J Gastrointest Surg DOI 10.1007/s11605-014-2545-x
2014 SSAT POSTER PRESENTATION
Management of Non-Parasitic Splenic Cysts: Does Size Really Matter? Christopher D. Kenney & Yumiko E. Hoeger & Amy K. Yetasook & John G. Linn & Ervin W. Denham & Joann Carbray & Michael B. Ujiki
Received: 26 January 2014 / Accepted: 13 May 2014 # 2014 The Society for Surgery of the Alimentary Tract
Abstract Background Splenic cysts are relatively rare clinical entities and are often diagnosed incidentally upon imaging conducted for a variety of clinical complaints. They can be categorized as primary or secondary based on the presence or absence of an epithelial lining. Primary cysts are further subdivided into those that are and are not secondary to parasitic infection. The treatment of nonparasitic splenic cysts (NPSC) has historically been dictated by two primary factors: the presence of symptoms attributable to the cyst and cyst size greater or less than 5 cm. While it is appropriate to resect a symptomatic lesion, the premise of recommending operative intervention based on size is not firmly supported by the literature. Methods In the current study, we identified 115 patients with splenic cysts and retrospectively reviewed their management that included aspiration, resection, or observation. Results Our data reveal a negative overall growth rate of asymptomatic cysts, a high recurrence rate after percutaneous drainage, as well as demonstrate the safety of observing asymptomatic lesions over time. Conclusion We conclude that observation of asymptomatic splenic cysts is safe regardless of size and that aspiration should be reserved for those who are not surgical candidates or in cases of diagnostic uncertainty. Keywords Spleen . Splenic cyst . Cyst size . Cyst management . Surgery
Introduction Splenic cysts are relatively uncommon and often found incidentally. True, primary splenic cysts have an epithelial lining and often result from parasitic infection, while secondary splenic cysts (pseudocysts) lack an epithelial lining and are secondary to trauma, infarction, or infection.1 Primary nonparasitic splenic cysts (NPSC) can be either congenital or neoplastic in origin, most of which are congenital cysts found
The contents of this manuscript were presented in poster format at the Digestive Diseases Week (SSAT) annual meeting in Orlando, FL May 18–21, 2013. C. D. Kenney : Y. E. Hoeger : A. K. Yetasook : J. G. Linn : E. W. Denham : J. Carbray : M. B. Ujiki (*) Department of Surgery, NorthShore University HealthSystem, 2650 Ridge Avenue, Evanston, IL 60201, USA e-mail: [email protected]
in children. A small subset is neoplastic and range from benign hemangiomas to more malignant angiosarcomas.2 In the USA, post-traumatic splenic pseudocysts are thought to be much more common than true splenic cysts and derive from either unresolved subcapsular hematomas or degeneration of splenic infarcts that organize to develop fluid-filled cysts.3 This notion has been questioned however as the high incidence of post-traumatic cysts may be related to their erroneous classification as failure to identify an epithelial cyst lining on pathologic examination has been shown to not always be a reflection of its true absence.4, 5 Increased understanding of the spleen’s role in immunologic function has led to the development of spleen-preserving techniques for non-parasitic lesions.1, 6, 7 Traumatic or spontaneous rupture resulting in hemorrhage,8 intra-abdominal abscess formation, and hypertension secondary to mass effect on the left kidney9, 10 are all possible sequelae of untreated cysts and avoidance of these complications serve as the foundation for the present management of these lesions. Surgical intervention is a well-tolerated approach for truly symptomatic patients, and it is generally accepted that this can be done laparoscopically in a safe manner. Percutaneous intervention,
J Gastrointest Surg
while a relatively benign procedure, has a high recurrence rate9–12 and should be reserved for cases of diagnostic uncertainty as well as for the provision of symptomatic relief in those patients who are not surgical candidates. Current surgical management of NPSCs is dictated by the presence or absence of symptoms and cyst size. It is often difficult however to differentiate between the asymptomatic and symptomatic splenic cyst. As the use of computed tomography (CT) imaging becomes pervasive in the workup of the common presenting complaint of abdominal pain the incidence of splenic cysts is likely to rise; however, for many of these patients, alternative etiologies for their complaints are often elucidated and the finding of a splenic cyst is truly incidental in nature. Regarding cyst size, cysts less than 5 cm are thought to resolve spontaneously and can be serially observed.13 Much debate has surrounded the question of how to treat patients with a cyst size greater than 5 cm. By and large, it is accepted that these lesions should undergo operative drainage or resection out of concern for rupture or malignant degeneration whether the patient is symptomatic or not. Currently, there is a lack of sufficient evidence to support this practice. We sought to understand the natural history of splenic cysts by retrospectively analyzing a large cohort of patients with the diagnosis of NPSC. To our knowledge, this is the largest single series to date of patients with splenic cysts of varying sizes that were managed by aspiration, surgical intervention, or observation.
Methods We performed a retrospective review of the electronic medical records of all patients who presented to any of the four hospitals associated with the NorthShore University HealthSystem between September 1999 and April 2011. The database was searched using the keyword “splenic cyst” which returned 1,033 patient encounters. The records of these patients were reviewed individually, and we identified 115 patients with evidence of a splenic cyst by diagnostic imaging report. This cohort formed the study group. We restricted our analysis to splenic cysts greater than 1 cm in size upon initial detection as lesions below this cutoff were considered to small to characterize. In the event that serial imaging demonstrated a decrease in cyst size below our cutoff for a lesion previously shown to be greater than 1 cm in size the data was maintained. Patient records were reviewed for history, inpatient and outpatient encounters, relevant diagnostic and interventional studies, pathology reports, perioperative information, and outcomes. A history of a fall, motor vehicle collision, or other specified trauma was considered to be a positive trauma history. We subdivided the 115 patients into those who underwent any type of intervention and those who were observed. Seven
patients underwent some form of intervention and were analyzed separately. The 108 patients in the untreated group were further stratified by cyst size to compare those patients who had untreated cysts less than or greater than 5 cm in size. For all untreated patients who underwent subsequent imaging, we calculated the growth rate of the splenic cysts for a period of up to 120 months and noted any complications during the period of observation. Statistical analysis was conducted using Microsoft Excel for Mac 2011 and Prism version 5.0. Results are expressed as mean±SD. Demographic comparisons between patients with cysts less than 5 cm in size were compared to those with cysts greater than or equal to 5 cm using two-tailed Fisher exact testing at a confidence level of 0.95. Statistical significance was established at an alpha level of 0.05. This study was approved by the NorthShore University HealthSystem Institutional Review Board under protocol # EH11-120.
Results Over an 11-year period, 115 patients were retrospectively identified with the diagnosis of a splenic cyst as verified by diagnostic imaging. Seven patients (6.1 %) underwent intervention. Patient demographics and cyst characteristics of the intervention group are presented in Table 1. All seven were female with a mean age of 25.4 years (range 16–41 years). All of the patients in the intervention group were symptomatic as evidenced by complaints considered secondary to the presence of a splenic cyst including left upper quadrant pain, nausea, vomiting, early satiety, and shortness of breath associated with abdominal fullness. The mean cyst size at initial presentation was 7.0±1.3 cm. Follow-up imaging was conducted in five patients allowing us to calculate the cyst growth rate of patients in the intervention group. Rates were calculated based on cyst size at initial diagnosis compared to
Table 1 Patient demographics and cyst characteristics of the intervention group Patient Age Sex Initial size Pre-P size Change Interval GR (cm/mo) (cm) (cm) (cm) (mo) B
16
F
7.7
7.9
0.2
5.7
0.03
5.1
0.2
26.4
0.01
C
41
F
4.9
D
25
F
6.1
E
21
F
8.2
8.6
0.4
17.0
0.02
F
16
F
8.5
8.5
0
7.4
0
G
40
F
6
H
19
F
7.5
9.5
2
1.9
1.05
Mean
25.4
7.0
7.9
0.6
11.7
0.22
SD
10.8
1.3
1.7
0.8
9.9
0.46
Pre-P pre-procedure, GR growth rate, SD standard deviation
J Gastrointest Surg
measurements obtained prior to either percutaneous or operative intervention (pre-procedure size). Based on these data we observed a positive growth rate of 0.22±0.46 cm/month. We were unable to calculate growth rates for two patients in this group. One patient (patient D) underwent cyst aspiration at an outside institution (records not available) and the other (patient G) underwent aspiration 2 weeks after initial diagnosis followed shortly by laparoscopic intervention without imaging in the intervening period. Trauma history, symptoms, and procedural details of the intervention group are presented in Table 2. Four patients underwent percutaneous aspiration as a first intervention. The mean initial cyst size in these patients was 7.4±1.5 cm. Despite aspirating a mean of 128±50 ml, all patients whose cysts were aspirated had recurrent symptoms and eventually underwent definitive surgical therapy. The three patients who were not subjected to aspiration underwent observation for a mean of 17.6±13.7 months and were found to have either cyst enlargement or escalation of symptoms and opted for elective cyst resection. Of the patients who underwent operative intervention, six of the procedures were accomplished in a laparoscopic fashion. Two patients underwent laparoscopic partial cystectomy; three had total splenectomies (two laparoscopic, one open) for cysts located in the splenic hilum; and two had laparoscopic cystectomies. Complications included a wound infection, an overnight re-admission for pain control, an intra-operative bowel injury, and a post-operative small-bowel obstruction requiring laparoscopic adhesiolysis 4 months after discharge. Pathologic review of the operative specimens revealed benign lesions in all cases. One hundred eight patients diagnosed with splenic cysts did not undergo intervention and were subdivided into two groups based on cyst size of less than or greater than 5 cm. Eighty-six patients were found to have cysts less than 5 cm in size. The mean age was 55.3 years (range 7–84 years), and the male to female ratio was 1:2.1 (28:58). Mean cyst size at diagnosis was 2.1±0.9 cm. Thirty-nine of these patients with a mean cyst size of 2.0±0.8 cm underwent subsequent imaging over a mean period of 35.3±31 months. Mean cyst size increased to 2.1±1.1 cm; however, we noted an overall
Table 2 Trauma history, symptoms, and procedural details of the intervention group LUQ left upper quadrant, Abd abdomen, SOB shortness of breath, N nausea, V vomiting, ES early satiety, Lap PC laparoscopic partial cystectomy, Lap C laparoscopic cystectomy, Lap S laparoscopic splenectomy, Spl splenectomy
growth rate of −0.01±0.07 cm/month. In two instances, a cyst revealed on initial imaging was found to be undetectable during the follow-up period implying spontaneous resolution of the cyst. There were no complications related to the presence of the cyst during the follow-up period. Twenty-two patients were found to have cysts greater than or equal to 5 cm; six of whom were lost to follow-up. Demographics and cyst characteristics of the remaining 16 patients are shown in Table 3. The mean age in this group was 55.4 years (range 22–95), and the mean cyst size at diagnosis was 7.5±4.8 cm. The male to female ratio was 1:2.2 (5:11). Additional imaging over a mean period of 63.7±46.3 months revealed that cyst size increased to a mean of 7.6±3.0 cm, but an overall growth rate of −0.06±0.22 cm/month was observed. There was one complication in the follow-up period that consisted of the death of a 95-year-old female who fell at home, rupturing an asymptomatic cyst, who subsequently expired due to urosepsis. Table 4 presents the grouped demographic data, including gender, race, trauma history, abdominal surgery history, and anticoagulant use. Patients with a history of trauma were found to have a statistically significant higher likelihood of having a cyst greater than or equal to 5 cm. In addition, patients with a history of prior abdominal surgery were also at higher likelihood of having a large (≥5 cm) cyst that also reached statistical significance.
Discussion Splenic cysts are relatively rare clinical entities; however, their incidence is likely to increase as a result of the widespread use of diagnostic imaging to evaluate abdominal complaints. Numerous complications of splenic cysts have been described, although their low incidence calls into question whether or not they, in and of themselves, should provide the impetus for surgical intervention. Hypertension9, 10 and malignancy14 have been reported but are extraordinarily rare events. Spontaneous and traumatic cyst rupture has also been described in several case reports and small series. Nonetheless, this also seems to be a rare occurrence with
Patient
Trauma
Symptoms
Aspiration
Recurrence
Procedure
Pathology
B
No
LUQ, ES
Yes
Yes
Lap PC
Epithelial cyst
C D E F G H
No Yes Yes No No Yes
L flank, N LUQ L Abd, SOB LUQ, N/V Abd, N LUQ
No Yes Yes No Yes No
Lap S Lap C Lap PC Lap S Lap C Spl
Hilar cyst Epithelial cyst Mesothelial cyst Epithelial cyst Lymphangioma Epidermoid cyst
Yes Yes Yes Yes
J Gastrointest Surg Table 3 Patient demographics and cyst characteristics in patients with cyst size greater than 5 cm not undergoing intervention Patient Age Sex Initial size Final size Change Interval GR (cm/mo) (cm) (cm) (cm) (mo) 1
35
F
2.2
7.2
5.0
84.2
2
81
F
11.0
10.4
−0.6
97.7
0.06 −0.01
3
62
F
5.3
5.9
0.6
87.1
0.01
4
32
F
8.8
7.4
−1.4
64.3
−0.02
5
78
F
6.0
7.9
1.9
60.1
0.03
6
57
M
6.0
6.0
0.0
31.3
0.00
7
22
M
6.5
6.5
0.0
86.4
0.00
8
56
M
5.0
5.6
0.6
38.2
0.02
9
95
F
9.7
9.7
0.0
1.3
0.00
10
46
M
5.2
5.1
−0.1
121
0.00
11
41
F
12.0
7.8
−4.2
5.1
−0.83
12
59
F
2.0
5.8
3.8
120.3
0.03
13
79
F
5.1
5.1
0.0
156.5
0.00
14
28
F
22.0
17.0
−5.0
21.8
−0.23
15
56
M
5.4
5.6
0.2
13.4
0.02
16
60
F
7.0
7.8
0.8
30.6
0.03
Mean
55.4
7.5
7.6
0.1
63.7
−0.06
SD
20.8
4.8
3.0
2.4
46.3
0.22
GR growth rate, SD standard deviation
few cases identified in the literature.8, 15–17 An often-cited 25 % risk of spontaneous cyst rupture with an attendant mortality rate of 20–25 % refers specifically to splenic hemangiomas,18 which differ considerably from simple cysts and can be differentiated from them based on imaging characteristics.2 Based on these putative risks found in studies involving both children and adults, the current recommendations are to observe asymptomatic lesions less than 5 cm in size and intervene upon those that are either symptomatic or greater than 5 cm. The origin of the 5-cm cutoff point for surgical intervention is elusive but seems to have originated in the 1992 report by Musy13 who described the treatment of eight pediatric patients with splenic cysts by either surgical or non-surgical means. In the surgical group, the mean age and cyst size were 13.5 years and 10.2 cm, respectively. The non-operative group had a mean age and cyst size of 6.5 years (including one newborn)
and 1.6 cm, respectively. The cyst noted at birth as a mass in the left upper quadrant measured 3.4 cm and was followed for 7 years at which time it was found to have grown to 4.8 cm. No further follow-up information was provided; however, the authors stated “neonatal cysts, when they grow over 5 cm, should be operated on”. It is unknown whether or not the patient underwent resection. It is plausible that the case of this neonate forms the basis of the 5-cm cutoff that has become surgical dogma. If this is indeed the case, one might question its indiscriminate application across all patient age groups as it stands to reason that a 5-cm cyst in a newborn is a distinct clinical entity compared to the same lesion in an adult patient. A 5-cm cutoff was reinforced by Pachter and colleagues.19 In this study over a 3-year period, seven symptomatic adult patients with post-traumatic cysts ranging from 7 to 15 cm in size were intervened upon in an elective surgical fashion. None of these patients, with the exception of vague abdominal complaints, suffered any complications from the presence of the cyst (i.e., abscess formation, rupture, hypertension). Five underwent cyst resection soon after presentation; the other two patients waited 3–6 months prior to operative intervention without consequence. Reflecting on Musy’s earlier work,13 the authors noted that two of the cysts found in that study were initially discovered at laparotomy as a result of hemoperitoneum and infection. This observation was promulgated as evidence for the notion that cysts greater than 5 cm in size should be intervened upon as they have a higher propensity to result in complications. In reviewing these two patients, it should be noted that hemoperitoneum was seen in a 15-yearold with a 10 cm cyst who was involved in a pedestrian vs. motor vehicle accident sustaining blunt abdominal trauma. The patient was stable at presentation and clinically deteriorated eventually requiring a laparotomy and subtotal cystectomy. Given the mechanism of injury in this pediatric patient, the size of the splenic lesion was likely of little consequence, as it would likely have ruptured regardless of its size. A second patient, age 12, presented with cyclic fevers, abdominal pain, vomiting, and diarrhea. Her workup, which included an ultrasound and computed tomography, demonstrated a 13 cm splenic cyst. The patient subsequently underwent splenectomy, and on pathologic examination the cyst was found to be superinfected with Salmonella that was
Table 4 Grouped demographics (%) Cyst size
Female gender White race Trauma history* Abdominal surgery history Anticoagulant use** ASA class median±SE
2014 SSAT POSTER PRESENTATION
Management of Non-Parasitic Splenic Cysts: Does Size Really Matter? Christopher D. Kenney & Yumiko E. Hoeger & Amy K. Yetasook & John G. Linn & Ervin W. Denham & Joann Carbray & Michael B. Ujiki
Received: 26 January 2014 / Accepted: 13 May 2014 # 2014 The Society for Surgery of the Alimentary Tract
Abstract Background Splenic cysts are relatively rare clinical entities and are often diagnosed incidentally upon imaging conducted for a variety of clinical complaints. They can be categorized as primary or secondary based on the presence or absence of an epithelial lining. Primary cysts are further subdivided into those that are and are not secondary to parasitic infection. The treatment of nonparasitic splenic cysts (NPSC) has historically been dictated by two primary factors: the presence of symptoms attributable to the cyst and cyst size greater or less than 5 cm. While it is appropriate to resect a symptomatic lesion, the premise of recommending operative intervention based on size is not firmly supported by the literature. Methods In the current study, we identified 115 patients with splenic cysts and retrospectively reviewed their management that included aspiration, resection, or observation. Results Our data reveal a negative overall growth rate of asymptomatic cysts, a high recurrence rate after percutaneous drainage, as well as demonstrate the safety of observing asymptomatic lesions over time. Conclusion We conclude that observation of asymptomatic splenic cysts is safe regardless of size and that aspiration should be reserved for those who are not surgical candidates or in cases of diagnostic uncertainty. Keywords Spleen . Splenic cyst . Cyst size . Cyst management . Surgery
Introduction Splenic cysts are relatively uncommon and often found incidentally. True, primary splenic cysts have an epithelial lining and often result from parasitic infection, while secondary splenic cysts (pseudocysts) lack an epithelial lining and are secondary to trauma, infarction, or infection.1 Primary nonparasitic splenic cysts (NPSC) can be either congenital or neoplastic in origin, most of which are congenital cysts found
The contents of this manuscript were presented in poster format at the Digestive Diseases Week (SSAT) annual meeting in Orlando, FL May 18–21, 2013. C. D. Kenney : Y. E. Hoeger : A. K. Yetasook : J. G. Linn : E. W. Denham : J. Carbray : M. B. Ujiki (*) Department of Surgery, NorthShore University HealthSystem, 2650 Ridge Avenue, Evanston, IL 60201, USA e-mail: [email protected]
in children. A small subset is neoplastic and range from benign hemangiomas to more malignant angiosarcomas.2 In the USA, post-traumatic splenic pseudocysts are thought to be much more common than true splenic cysts and derive from either unresolved subcapsular hematomas or degeneration of splenic infarcts that organize to develop fluid-filled cysts.3 This notion has been questioned however as the high incidence of post-traumatic cysts may be related to their erroneous classification as failure to identify an epithelial cyst lining on pathologic examination has been shown to not always be a reflection of its true absence.4, 5 Increased understanding of the spleen’s role in immunologic function has led to the development of spleen-preserving techniques for non-parasitic lesions.1, 6, 7 Traumatic or spontaneous rupture resulting in hemorrhage,8 intra-abdominal abscess formation, and hypertension secondary to mass effect on the left kidney9, 10 are all possible sequelae of untreated cysts and avoidance of these complications serve as the foundation for the present management of these lesions. Surgical intervention is a well-tolerated approach for truly symptomatic patients, and it is generally accepted that this can be done laparoscopically in a safe manner. Percutaneous intervention,
J Gastrointest Surg
while a relatively benign procedure, has a high recurrence rate9–12 and should be reserved for cases of diagnostic uncertainty as well as for the provision of symptomatic relief in those patients who are not surgical candidates. Current surgical management of NPSCs is dictated by the presence or absence of symptoms and cyst size. It is often difficult however to differentiate between the asymptomatic and symptomatic splenic cyst. As the use of computed tomography (CT) imaging becomes pervasive in the workup of the common presenting complaint of abdominal pain the incidence of splenic cysts is likely to rise; however, for many of these patients, alternative etiologies for their complaints are often elucidated and the finding of a splenic cyst is truly incidental in nature. Regarding cyst size, cysts less than 5 cm are thought to resolve spontaneously and can be serially observed.13 Much debate has surrounded the question of how to treat patients with a cyst size greater than 5 cm. By and large, it is accepted that these lesions should undergo operative drainage or resection out of concern for rupture or malignant degeneration whether the patient is symptomatic or not. Currently, there is a lack of sufficient evidence to support this practice. We sought to understand the natural history of splenic cysts by retrospectively analyzing a large cohort of patients with the diagnosis of NPSC. To our knowledge, this is the largest single series to date of patients with splenic cysts of varying sizes that were managed by aspiration, surgical intervention, or observation.
Methods We performed a retrospective review of the electronic medical records of all patients who presented to any of the four hospitals associated with the NorthShore University HealthSystem between September 1999 and April 2011. The database was searched using the keyword “splenic cyst” which returned 1,033 patient encounters. The records of these patients were reviewed individually, and we identified 115 patients with evidence of a splenic cyst by diagnostic imaging report. This cohort formed the study group. We restricted our analysis to splenic cysts greater than 1 cm in size upon initial detection as lesions below this cutoff were considered to small to characterize. In the event that serial imaging demonstrated a decrease in cyst size below our cutoff for a lesion previously shown to be greater than 1 cm in size the data was maintained. Patient records were reviewed for history, inpatient and outpatient encounters, relevant diagnostic and interventional studies, pathology reports, perioperative information, and outcomes. A history of a fall, motor vehicle collision, or other specified trauma was considered to be a positive trauma history. We subdivided the 115 patients into those who underwent any type of intervention and those who were observed. Seven
patients underwent some form of intervention and were analyzed separately. The 108 patients in the untreated group were further stratified by cyst size to compare those patients who had untreated cysts less than or greater than 5 cm in size. For all untreated patients who underwent subsequent imaging, we calculated the growth rate of the splenic cysts for a period of up to 120 months and noted any complications during the period of observation. Statistical analysis was conducted using Microsoft Excel for Mac 2011 and Prism version 5.0. Results are expressed as mean±SD. Demographic comparisons between patients with cysts less than 5 cm in size were compared to those with cysts greater than or equal to 5 cm using two-tailed Fisher exact testing at a confidence level of 0.95. Statistical significance was established at an alpha level of 0.05. This study was approved by the NorthShore University HealthSystem Institutional Review Board under protocol # EH11-120.
Results Over an 11-year period, 115 patients were retrospectively identified with the diagnosis of a splenic cyst as verified by diagnostic imaging. Seven patients (6.1 %) underwent intervention. Patient demographics and cyst characteristics of the intervention group are presented in Table 1. All seven were female with a mean age of 25.4 years (range 16–41 years). All of the patients in the intervention group were symptomatic as evidenced by complaints considered secondary to the presence of a splenic cyst including left upper quadrant pain, nausea, vomiting, early satiety, and shortness of breath associated with abdominal fullness. The mean cyst size at initial presentation was 7.0±1.3 cm. Follow-up imaging was conducted in five patients allowing us to calculate the cyst growth rate of patients in the intervention group. Rates were calculated based on cyst size at initial diagnosis compared to
Table 1 Patient demographics and cyst characteristics of the intervention group Patient Age Sex Initial size Pre-P size Change Interval GR (cm/mo) (cm) (cm) (cm) (mo) B
16
F
7.7
7.9
0.2
5.7
0.03
5.1
0.2
26.4
0.01
C
41
F
4.9
D
25
F
6.1
E
21
F
8.2
8.6
0.4
17.0
0.02
F
16
F
8.5
8.5
0
7.4
0
G
40
F
6
H
19
F
7.5
9.5
2
1.9
1.05
Mean
25.4
7.0
7.9
0.6
11.7
0.22
SD
10.8
1.3
1.7
0.8
9.9
0.46
Pre-P pre-procedure, GR growth rate, SD standard deviation
J Gastrointest Surg
measurements obtained prior to either percutaneous or operative intervention (pre-procedure size). Based on these data we observed a positive growth rate of 0.22±0.46 cm/month. We were unable to calculate growth rates for two patients in this group. One patient (patient D) underwent cyst aspiration at an outside institution (records not available) and the other (patient G) underwent aspiration 2 weeks after initial diagnosis followed shortly by laparoscopic intervention without imaging in the intervening period. Trauma history, symptoms, and procedural details of the intervention group are presented in Table 2. Four patients underwent percutaneous aspiration as a first intervention. The mean initial cyst size in these patients was 7.4±1.5 cm. Despite aspirating a mean of 128±50 ml, all patients whose cysts were aspirated had recurrent symptoms and eventually underwent definitive surgical therapy. The three patients who were not subjected to aspiration underwent observation for a mean of 17.6±13.7 months and were found to have either cyst enlargement or escalation of symptoms and opted for elective cyst resection. Of the patients who underwent operative intervention, six of the procedures were accomplished in a laparoscopic fashion. Two patients underwent laparoscopic partial cystectomy; three had total splenectomies (two laparoscopic, one open) for cysts located in the splenic hilum; and two had laparoscopic cystectomies. Complications included a wound infection, an overnight re-admission for pain control, an intra-operative bowel injury, and a post-operative small-bowel obstruction requiring laparoscopic adhesiolysis 4 months after discharge. Pathologic review of the operative specimens revealed benign lesions in all cases. One hundred eight patients diagnosed with splenic cysts did not undergo intervention and were subdivided into two groups based on cyst size of less than or greater than 5 cm. Eighty-six patients were found to have cysts less than 5 cm in size. The mean age was 55.3 years (range 7–84 years), and the male to female ratio was 1:2.1 (28:58). Mean cyst size at diagnosis was 2.1±0.9 cm. Thirty-nine of these patients with a mean cyst size of 2.0±0.8 cm underwent subsequent imaging over a mean period of 35.3±31 months. Mean cyst size increased to 2.1±1.1 cm; however, we noted an overall
Table 2 Trauma history, symptoms, and procedural details of the intervention group LUQ left upper quadrant, Abd abdomen, SOB shortness of breath, N nausea, V vomiting, ES early satiety, Lap PC laparoscopic partial cystectomy, Lap C laparoscopic cystectomy, Lap S laparoscopic splenectomy, Spl splenectomy
growth rate of −0.01±0.07 cm/month. In two instances, a cyst revealed on initial imaging was found to be undetectable during the follow-up period implying spontaneous resolution of the cyst. There were no complications related to the presence of the cyst during the follow-up period. Twenty-two patients were found to have cysts greater than or equal to 5 cm; six of whom were lost to follow-up. Demographics and cyst characteristics of the remaining 16 patients are shown in Table 3. The mean age in this group was 55.4 years (range 22–95), and the mean cyst size at diagnosis was 7.5±4.8 cm. The male to female ratio was 1:2.2 (5:11). Additional imaging over a mean period of 63.7±46.3 months revealed that cyst size increased to a mean of 7.6±3.0 cm, but an overall growth rate of −0.06±0.22 cm/month was observed. There was one complication in the follow-up period that consisted of the death of a 95-year-old female who fell at home, rupturing an asymptomatic cyst, who subsequently expired due to urosepsis. Table 4 presents the grouped demographic data, including gender, race, trauma history, abdominal surgery history, and anticoagulant use. Patients with a history of trauma were found to have a statistically significant higher likelihood of having a cyst greater than or equal to 5 cm. In addition, patients with a history of prior abdominal surgery were also at higher likelihood of having a large (≥5 cm) cyst that also reached statistical significance.
Discussion Splenic cysts are relatively rare clinical entities; however, their incidence is likely to increase as a result of the widespread use of diagnostic imaging to evaluate abdominal complaints. Numerous complications of splenic cysts have been described, although their low incidence calls into question whether or not they, in and of themselves, should provide the impetus for surgical intervention. Hypertension9, 10 and malignancy14 have been reported but are extraordinarily rare events. Spontaneous and traumatic cyst rupture has also been described in several case reports and small series. Nonetheless, this also seems to be a rare occurrence with
Patient
Trauma
Symptoms
Aspiration
Recurrence
Procedure
Pathology
B
No
LUQ, ES
Yes
Yes
Lap PC
Epithelial cyst
C D E F G H
No Yes Yes No No Yes
L flank, N LUQ L Abd, SOB LUQ, N/V Abd, N LUQ
No Yes Yes No Yes No
Lap S Lap C Lap PC Lap S Lap C Spl
Hilar cyst Epithelial cyst Mesothelial cyst Epithelial cyst Lymphangioma Epidermoid cyst
Yes Yes Yes Yes
J Gastrointest Surg Table 3 Patient demographics and cyst characteristics in patients with cyst size greater than 5 cm not undergoing intervention Patient Age Sex Initial size Final size Change Interval GR (cm/mo) (cm) (cm) (cm) (mo) 1
35
F
2.2
7.2
5.0
84.2
2
81
F
11.0
10.4
−0.6
97.7
0.06 −0.01
3
62
F
5.3
5.9
0.6
87.1
0.01
4
32
F
8.8
7.4
−1.4
64.3
−0.02
5
78
F
6.0
7.9
1.9
60.1
0.03
6
57
M
6.0
6.0
0.0
31.3
0.00
7
22
M
6.5
6.5
0.0
86.4
0.00
8
56
M
5.0
5.6
0.6
38.2
0.02
9
95
F
9.7
9.7
0.0
1.3
0.00
10
46
M
5.2
5.1
−0.1
121
0.00
11
41
F
12.0
7.8
−4.2
5.1
−0.83
12
59
F
2.0
5.8
3.8
120.3
0.03
13
79
F
5.1
5.1
0.0
156.5
0.00
14
28
F
22.0
17.0
−5.0
21.8
−0.23
15
56
M
5.4
5.6
0.2
13.4
0.02
16
60
F
7.0
7.8
0.8
30.6
0.03
Mean
55.4
7.5
7.6
0.1
63.7
−0.06
SD
20.8
4.8
3.0
2.4
46.3
0.22
GR growth rate, SD standard deviation
few cases identified in the literature.8, 15–17 An often-cited 25 % risk of spontaneous cyst rupture with an attendant mortality rate of 20–25 % refers specifically to splenic hemangiomas,18 which differ considerably from simple cysts and can be differentiated from them based on imaging characteristics.2 Based on these putative risks found in studies involving both children and adults, the current recommendations are to observe asymptomatic lesions less than 5 cm in size and intervene upon those that are either symptomatic or greater than 5 cm. The origin of the 5-cm cutoff point for surgical intervention is elusive but seems to have originated in the 1992 report by Musy13 who described the treatment of eight pediatric patients with splenic cysts by either surgical or non-surgical means. In the surgical group, the mean age and cyst size were 13.5 years and 10.2 cm, respectively. The non-operative group had a mean age and cyst size of 6.5 years (including one newborn)
and 1.6 cm, respectively. The cyst noted at birth as a mass in the left upper quadrant measured 3.4 cm and was followed for 7 years at which time it was found to have grown to 4.8 cm. No further follow-up information was provided; however, the authors stated “neonatal cysts, when they grow over 5 cm, should be operated on”. It is unknown whether or not the patient underwent resection. It is plausible that the case of this neonate forms the basis of the 5-cm cutoff that has become surgical dogma. If this is indeed the case, one might question its indiscriminate application across all patient age groups as it stands to reason that a 5-cm cyst in a newborn is a distinct clinical entity compared to the same lesion in an adult patient. A 5-cm cutoff was reinforced by Pachter and colleagues.19 In this study over a 3-year period, seven symptomatic adult patients with post-traumatic cysts ranging from 7 to 15 cm in size were intervened upon in an elective surgical fashion. None of these patients, with the exception of vague abdominal complaints, suffered any complications from the presence of the cyst (i.e., abscess formation, rupture, hypertension). Five underwent cyst resection soon after presentation; the other two patients waited 3–6 months prior to operative intervention without consequence. Reflecting on Musy’s earlier work,13 the authors noted that two of the cysts found in that study were initially discovered at laparotomy as a result of hemoperitoneum and infection. This observation was promulgated as evidence for the notion that cysts greater than 5 cm in size should be intervened upon as they have a higher propensity to result in complications. In reviewing these two patients, it should be noted that hemoperitoneum was seen in a 15-yearold with a 10 cm cyst who was involved in a pedestrian vs. motor vehicle accident sustaining blunt abdominal trauma. The patient was stable at presentation and clinically deteriorated eventually requiring a laparotomy and subtotal cystectomy. Given the mechanism of injury in this pediatric patient, the size of the splenic lesion was likely of little consequence, as it would likely have ruptured regardless of its size. A second patient, age 12, presented with cyclic fevers, abdominal pain, vomiting, and diarrhea. Her workup, which included an ultrasound and computed tomography, demonstrated a 13 cm splenic cyst. The patient subsequently underwent splenectomy, and on pathologic examination the cyst was found to be superinfected with Salmonella that was
Table 4 Grouped demographics (%) Cyst size
Female gender White race Trauma history* Abdominal surgery history Anticoagulant use** ASA class median±SE
