ª Springer Science+Business Media New York 2014
Abdominal Imaging
Abdom Imaging (2014) DOI: 10.1007/s00261-014-0142-9
Retroperitoneal lobular capillary hemangioma with synchronous ipsilateral renal cell carcinoma David W. Brandel, Mahmoud M. Al-Hawary, Ashish P. Wasnik Division of Abdominal Imaging, Department of Radiology, University of Michigan Health System, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA
Abstract Lobular capillary hemangiomas (LCH) are acquired benign vascular tumors of skin and mucosal spaces of head and neck. Very few cases of LCH have been reported in the abdomen, predominantly occurring as mucosal polyps in the bowel. We present CT imaging features of solitary retroperitoneal LCH in a patient with synchronous ipsilateral renal cell carcinoma and review the available literature and imaging features in abdominal and extraabdominal LCH. To our knowledge, there is no other case of retroperitoneal LCH available in the English literature. Key words: Lobular capillary hemangioma—Benign tumor—Retroperitoneum—Retroperitoneal tumor—CT imaging
Case report A 56-year-old woman presented to the emergency department for acute onset chest pain, warranting a CT evaluation, which was positive for acute pulmonary embolism, thereby prompting admission and treatment. The abdominal portion of the CT scan revealed a solid enhancing 2.5-cm mass in the lower pole of the left kidney (Fig. 1), most concerning for renal cell carcinoma. There was no evidence of renal vein invasion, lymph node enlargement, or distant metastases. However, there was a 3.3-cm well-circumscribed mass in the left para-aortic region caudal to left renal vein (Fig. 2a, b), demonstrating peripheral avid enhancement and central heterogeneous hypodensity with web-like septations/speckled appearance. Differential consideration of the solitary retroperitoneal mass included paraganglioma and other benign and malignant retroperitoneal tumors, Correspondence to: Ashish P. Wasnik; email: [email protected]
including sarcoma. In light of the differences in imaging appearance with respect to the renal parenchymal lesion, metastasis was considered less likely. Biochemical workup, including a plasma metanephrine level, was within normal limits. Given uncertain clinical and imaging findings, as well as the presumed renal malignancy, the patient elected to undergo excisional biopsy. Laparoscopic surgery was performed, revealing a 2.8 9 2.5 9 1.8 cm gelatinous mass with fleshy and hemorrhagic appearing parenchyma. The lesion was completely excised with negative margins. Immunohistochemical analysis yielded a final diagnosis of lobular capillary hemangioma. Subsequent percutaneous imageguided biopsy of the left kidney lesion was positive for renal cell carcinoma, which was later treated by radiofrequency ablation.
Discussion Lobular capillary hemangiomas (LCH), formerly known as pyogenic granuloma, are acquired benign mucocutaneous vascular tumors [1]. They are a subtype of capillary hemangioma characterized by lobules of capillaries surrounding angular vessels lined by bland endothelial cells [2]. LCH are predominantly found in the pediatric population, with peak incidence occurring in the second decade of life [3]. There is some variation in the available literature regarding gender predilection, although the overall data suggest that LCH are more common in males within the pediatric age group, and females thereafter [1, 4]. The most common etiology is idiopathic, although local trauma and pregnancy have occasionally been implicated in etiopathogenesis [4]. Cutaneous involvement accounts for approximately 86% of cases [4]. These lesions can also affect the mucosal spaces of the head and neck, most commonly the lips, nose, and oral cavity [2]. In the available literature, there are only a handful of reported cases of LCH occurring within the abdomen
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
and pelvis. Several of these presented as intraluminal polyps along the mucosal surface of the bowel [5–9], two were intravascular [10, 11], and one intrahepatic [12]. Although imaging may be able to play an important role in characterizing abdominal LCH, their scarce nature has, thus far, precluded a definitive analysis of their imaging features. In the bowel lumen, where the majority has occurred, endoscopy is superior in both its capacity to visualize the lesion and obtain tissue sampling for histologic diagnosis. Mucocutaneous LCH are usually clinically visible and, thus, uncommonly imaged. In some instances,
sinonasal LCH are evaluated by CT when the diagnosis is uncertain, or to further define their extent. In 2010, Lee et al characterized the CT appearance of nasal LCH in a small group of six adult patients [13]. On unenhanced imaging, the lesions all appeared isodense or hypodense to the masticator muscle. Following contrast administration, nearly all (5/6) LCH demonstrated two distinct morphologic components: a lobular, intensely enhancing portion, and a low attenuation portion with speckled internal enhancement [13]. Our case demonstrates a similar pattern of peripheral avid enhancement and central heterogeneity with speckled appearance. Puxeddu et al. [14] described sinonasal LCH as an intensely enhancing lesion, with no mention of internal heterogeneity. Lee et al. [13] have postulated that the enhancing component may represent the radiographic appearance of the lobular capillary tissue which defines this pathologic entity and that the low-attenuation/speckled component may represent ulceration. This hypothesis is strengthened by Smith et al, who performed a clinicopathologic analysis of 34 cases of LCH, finding ulceration to occur in 68% of cases [2]. However, until now, no radiopathologic analysis has been performed to investigate this supposition. Intravascular LCH (IVLCH) is a rare variant developing from the vasa vasorum, first described by Cooper et al in 1979 [15]. IVLCH almost exclusively involve the veins of the head and neck, where ultrasound is useful in evaluation, typically demonstrating a heterogeneously echoic, intensely vascular mass within the vessel lumen [16, 17]. Until now, only two reports of IVLCH within the abdomen and pelvis exist. One arising within the right internal iliac vein, described by Pradhan et al. in 2008 [10] demonstrated incomplete obstruction of the
Fig. 2. A Axial and B coronal reformatted contrast enhanced CT image shows a retroperitoneal left para-aortic mass (arrow) with peripheral enhancement and more heterogeneous
hypodense central portion. Laparoscopic resection with immunohistochemical staining confirmed lobular capillary hemangioma (Ao aorta).
Fig. 1. Coronal reformatted contrast enhanced CT image shows a heterogeneous hyperdense mass (arrowhead) in the lower pole of left kidney (LK), biopsy proven to be renal cell carcinoma.
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
vessel lumen and appeared well-circumscribed, with heterogeneous central enhancement, and avid peripheral enhancement. In 2012, a 10 9 5.1 9 4.6 cm LCH originating within and occluding the left renal vein, with extension into the renal hilum and IVC, was described [11]. Although the large size of this neoplasm is atypical of LCH, it also demonstrated avid peripheral and heterogeneous central enhancement. There is a single documented case of intrathoracic IVLCH, arising in the azygos vein, which demonstrated intense peripheral enhancement, akin to the abdominal IVLCH [18]. This case was unique in demonstrating multiple post-contrast phases, showing progressive central enhancement over time. Similar to the more typical venous and cavernous hemangiomas, this LCH displayed progressive central enhancement, although whether this follows the wellestablished doctrine of discontinuous, nodular, centripetal filling remains to be seen. MRI has been used to study IVLCH, as well as those occurring within the head/neck, digits, and central nervous system. LCH within the spinal cord are most likely to occur near the lower thoracic and lumbar spine, a predisposition that may be related to the common mesodermal elements shared by the distal neuroepithelium and LCH [19]. On T1 weighted imaging, LCH appear isointense to muscle and vascular structures; on T2 weighted sequences, they are markedly hyperintense; and following gadolinium administration, they are homogeneously avidly enhancing [16–20]. These features are consistent with the vascular nature of LCH. Within the abdomen, a single case of intrahepatic LCH presented as a 5-cm mass within the right lobe of the liver [11]. This demonstrated MRI characteristics similar to those above, with the exception of a T2 hypointense central scar that demonstrated progressive contrast enhancement over time, similar to focal nodular hyperplasia (FNH). Unlike FNH, however, LCH would not be expected to enhance with a hepatocyte specific intravascular contrast agent. This case also further serves to illustrate that larger LCH may contain a central fibrotic component that does not rapidly enhance on CT or MRI, but may fill-in with contrast over time. In formulating the differential diagnosis of a primary retroperitoneal mass, consideration should always be given to malignant entities, which are much more common. A large population based study in the Netherlands found that 80% of non-visceral retroperitoneal neoplasms were malignant, with sarcoma, lymphoma, and carcinomas of unknown primary predominating [21]. Less common considerations include paraganglioma, arteriovenous malformation, and hemangioma. Among primary retroperitoneal hemangiomas, which are extremely rare as a group, the cavernous and venous subtypes are most likely, with only a few documented reports of capillary subtypes, including LCH [22].
Conclusion Although classically a mucocutaneous lesion, the radiologist should be aware that LCH can manifest within the abdomen and pelvis. LCH may be seen within the lumen of the bowel and veins or may present as a lesion within the spinal canal, abdominal viscera, and retroperitoneum. Although limited data regarding the imaging appearance of abdominal LCH are available, their characteristics are thus far consistent with those of LCH seen elsewhere in the body. On CT, they appear as low attenuation lesions with avid peripheral and heterogeneous central enhancement. On MRI, they are T2 hyperintense and demonstrate avid post-contrast enhancement. Further analysis with larger patient population may lead to a more concrete imaging pattern that can help to more reliably distinguished from malignant lesions.
References 1. Patrice SJ, Wiss K, Mulliken JB (1991) Pyogenic granuloma (lobular capillary hemangioma): a clinicopathologic study of 178 cases. Pediatr Dermatol 8(4):267–276 2. Smith SC, Patel RM, Lucas DR, McHugh JB (2013) Sinonasal lobular capillary hemangioma: a clinicopathologic study of 34 cases characterizing potential for local recurrence. Head Neck Pathol 7(2):129–134 3. Mills SE, Cooper PH, Fechner RE (1980) Lobular capillary hemangioma: the underlying lesion of pyogenic granuloma. A study of 73 cases from the oral and nasal mucus membranes. Am J Surg Pathol 4(5):470–479 4. Harris MN, Desai R, Chuang TY, Hood AF, Mirowski GW (2000) Lobular capillary hemangiomas: an epidemiologic report, with emphasis on cutaneous lesions. J Am Acad Dermatol 42(6):1012– 1016 5. Stojsic Z, Brasanac D, Kokai G, et al. (2008) Intestinal intussusception due to a pyogenic granuloma. Turk J Pediatr 50(6):600–603 6. Carmen Gonza´lez-Vela M, Fernando Val-Bernal J, Francisca Garijo M, Garcı´ a-Sua´rez C (2005) Pyogenic granuloma of the sigmoid colon. Ann Diagn Pathol 9(2):106–109 7. van Eeden S, Offerhaus GJ, Morsink FH, et al. (2004) Pyogenic granuloma, an unrecognized cause of gastrointestinal bleeding. Virchows Arch 444(6):590–593 8. Nagoya H, Tanaka S, Tatsuguchi A, et al. (2010) Rare cause of obscure gastrointestinal bleeding due to pyogenic granuloma in the ileum detected by capsule endoscopy and treated by double balloon endoscopy. Dig Endosc 22(1):71–73 9. Val-Bernal JF, Mayorga M, Garcia-Somacarrera E (2012) Pyogenic granuloma of the large intestine: case report and review of reported cases in the adult. Pathol Res Pract 208(11):687–690 10. Pradhan S, Bazan H, Salem R, Gusberg RJ (2008) Intravenous lobular capillary hemangioma originating in the iliac veins: a case report. J Vasc Surg 47(6):1346–1349 11. Takeuchi M, Hara S, Itoh T (2012) A case of intravenous lobular capillary hemangioma of the renal vein mimicking renal cell carcinoma. Pathol Int 62(6):441–443 12. Abaalkhail F, Castonguay M, Driman DK, Parfitt J, Marotta P (2009) Lobular capillary hemangioma of the liver. Hepatobiliary Pancreat Dis Int 8(3):323–325 13. Lee DG, Lee SK, Chang HW, et al. (2010) CT features of lobular capillary hemangioma of the nasal cavity. AJNR Am J Neuroradiol 31(4):749–754 14. Puxeddu R, Berlucchi M, Ledda GP, et al. (2006) Lobular capillary hemangioma of the nasal cavity: a retrospective study on 40 patients. Am J Rhinol 20(4):480–484 15. Cooper PH, McAllister HA, Helwig EB (1979) Intravenous pyogenic granuloma. A study of 18 cases. Am J Surg Pathol 3:221–228
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
16. Ahn SE, Park JS, Ryu KN, Jin W, Park SY (2013) Intravenous lobular capillary hemangioma occurring in the cephalic vein of a 39-year-old adult. J Clin Ultrasound. doi:10.1002/jcu.22110 17. Maher A (2010) Intravenous lobular capillary hemangioma. Ann Vasc Surg 24(7):951 18. Nyugen BD (2014) Imaging of intravenous lobular capillary hemangioma of azygos vein. Clin Nucl Med 39(1):114–116 19. Andaluz N, Balko MG, Stanek J, Morgan C, Schwetschenau PR (2002) Lobular capillary hemangioma of the spinal cord: case report and review of the literature. J Neurooncol 56(3):261–264
20. Baek HJ, Sun JL, Kil HC, et al. (2010) Subungual tumors: clinicopathologic correlation with US and MR imaging findings. Radiographics 30(6):1621–1636 21. Dalen T, Coebergh JW, Casparie MK, et al. (2001) Soft tissue sarcoma: the predominant primary malignancy in the retroperitoneum. Sarcoma 5(1):5–8 22. Godar M, Yuan Q, Shakya R, Xia Y, Zhang P (2013) Mixed capillary venous retroperitoneal hemangioma. Case Rep Radiol 2013:258352
Abdominal Imaging
Abdom Imaging (2014) DOI: 10.1007/s00261-014-0142-9
Retroperitoneal lobular capillary hemangioma with synchronous ipsilateral renal cell carcinoma David W. Brandel, Mahmoud M. Al-Hawary, Ashish P. Wasnik Division of Abdominal Imaging, Department of Radiology, University of Michigan Health System, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA
Abstract Lobular capillary hemangiomas (LCH) are acquired benign vascular tumors of skin and mucosal spaces of head and neck. Very few cases of LCH have been reported in the abdomen, predominantly occurring as mucosal polyps in the bowel. We present CT imaging features of solitary retroperitoneal LCH in a patient with synchronous ipsilateral renal cell carcinoma and review the available literature and imaging features in abdominal and extraabdominal LCH. To our knowledge, there is no other case of retroperitoneal LCH available in the English literature. Key words: Lobular capillary hemangioma—Benign tumor—Retroperitoneum—Retroperitoneal tumor—CT imaging
Case report A 56-year-old woman presented to the emergency department for acute onset chest pain, warranting a CT evaluation, which was positive for acute pulmonary embolism, thereby prompting admission and treatment. The abdominal portion of the CT scan revealed a solid enhancing 2.5-cm mass in the lower pole of the left kidney (Fig. 1), most concerning for renal cell carcinoma. There was no evidence of renal vein invasion, lymph node enlargement, or distant metastases. However, there was a 3.3-cm well-circumscribed mass in the left para-aortic region caudal to left renal vein (Fig. 2a, b), demonstrating peripheral avid enhancement and central heterogeneous hypodensity with web-like septations/speckled appearance. Differential consideration of the solitary retroperitoneal mass included paraganglioma and other benign and malignant retroperitoneal tumors, Correspondence to: Ashish P. Wasnik; email: [email protected]
including sarcoma. In light of the differences in imaging appearance with respect to the renal parenchymal lesion, metastasis was considered less likely. Biochemical workup, including a plasma metanephrine level, was within normal limits. Given uncertain clinical and imaging findings, as well as the presumed renal malignancy, the patient elected to undergo excisional biopsy. Laparoscopic surgery was performed, revealing a 2.8 9 2.5 9 1.8 cm gelatinous mass with fleshy and hemorrhagic appearing parenchyma. The lesion was completely excised with negative margins. Immunohistochemical analysis yielded a final diagnosis of lobular capillary hemangioma. Subsequent percutaneous imageguided biopsy of the left kidney lesion was positive for renal cell carcinoma, which was later treated by radiofrequency ablation.
Discussion Lobular capillary hemangiomas (LCH), formerly known as pyogenic granuloma, are acquired benign mucocutaneous vascular tumors [1]. They are a subtype of capillary hemangioma characterized by lobules of capillaries surrounding angular vessels lined by bland endothelial cells [2]. LCH are predominantly found in the pediatric population, with peak incidence occurring in the second decade of life [3]. There is some variation in the available literature regarding gender predilection, although the overall data suggest that LCH are more common in males within the pediatric age group, and females thereafter [1, 4]. The most common etiology is idiopathic, although local trauma and pregnancy have occasionally been implicated in etiopathogenesis [4]. Cutaneous involvement accounts for approximately 86% of cases [4]. These lesions can also affect the mucosal spaces of the head and neck, most commonly the lips, nose, and oral cavity [2]. In the available literature, there are only a handful of reported cases of LCH occurring within the abdomen
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
and pelvis. Several of these presented as intraluminal polyps along the mucosal surface of the bowel [5–9], two were intravascular [10, 11], and one intrahepatic [12]. Although imaging may be able to play an important role in characterizing abdominal LCH, their scarce nature has, thus far, precluded a definitive analysis of their imaging features. In the bowel lumen, where the majority has occurred, endoscopy is superior in both its capacity to visualize the lesion and obtain tissue sampling for histologic diagnosis. Mucocutaneous LCH are usually clinically visible and, thus, uncommonly imaged. In some instances,
sinonasal LCH are evaluated by CT when the diagnosis is uncertain, or to further define their extent. In 2010, Lee et al characterized the CT appearance of nasal LCH in a small group of six adult patients [13]. On unenhanced imaging, the lesions all appeared isodense or hypodense to the masticator muscle. Following contrast administration, nearly all (5/6) LCH demonstrated two distinct morphologic components: a lobular, intensely enhancing portion, and a low attenuation portion with speckled internal enhancement [13]. Our case demonstrates a similar pattern of peripheral avid enhancement and central heterogeneity with speckled appearance. Puxeddu et al. [14] described sinonasal LCH as an intensely enhancing lesion, with no mention of internal heterogeneity. Lee et al. [13] have postulated that the enhancing component may represent the radiographic appearance of the lobular capillary tissue which defines this pathologic entity and that the low-attenuation/speckled component may represent ulceration. This hypothesis is strengthened by Smith et al, who performed a clinicopathologic analysis of 34 cases of LCH, finding ulceration to occur in 68% of cases [2]. However, until now, no radiopathologic analysis has been performed to investigate this supposition. Intravascular LCH (IVLCH) is a rare variant developing from the vasa vasorum, first described by Cooper et al in 1979 [15]. IVLCH almost exclusively involve the veins of the head and neck, where ultrasound is useful in evaluation, typically demonstrating a heterogeneously echoic, intensely vascular mass within the vessel lumen [16, 17]. Until now, only two reports of IVLCH within the abdomen and pelvis exist. One arising within the right internal iliac vein, described by Pradhan et al. in 2008 [10] demonstrated incomplete obstruction of the
Fig. 2. A Axial and B coronal reformatted contrast enhanced CT image shows a retroperitoneal left para-aortic mass (arrow) with peripheral enhancement and more heterogeneous
hypodense central portion. Laparoscopic resection with immunohistochemical staining confirmed lobular capillary hemangioma (Ao aorta).
Fig. 1. Coronal reformatted contrast enhanced CT image shows a heterogeneous hyperdense mass (arrowhead) in the lower pole of left kidney (LK), biopsy proven to be renal cell carcinoma.
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
vessel lumen and appeared well-circumscribed, with heterogeneous central enhancement, and avid peripheral enhancement. In 2012, a 10 9 5.1 9 4.6 cm LCH originating within and occluding the left renal vein, with extension into the renal hilum and IVC, was described [11]. Although the large size of this neoplasm is atypical of LCH, it also demonstrated avid peripheral and heterogeneous central enhancement. There is a single documented case of intrathoracic IVLCH, arising in the azygos vein, which demonstrated intense peripheral enhancement, akin to the abdominal IVLCH [18]. This case was unique in demonstrating multiple post-contrast phases, showing progressive central enhancement over time. Similar to the more typical venous and cavernous hemangiomas, this LCH displayed progressive central enhancement, although whether this follows the wellestablished doctrine of discontinuous, nodular, centripetal filling remains to be seen. MRI has been used to study IVLCH, as well as those occurring within the head/neck, digits, and central nervous system. LCH within the spinal cord are most likely to occur near the lower thoracic and lumbar spine, a predisposition that may be related to the common mesodermal elements shared by the distal neuroepithelium and LCH [19]. On T1 weighted imaging, LCH appear isointense to muscle and vascular structures; on T2 weighted sequences, they are markedly hyperintense; and following gadolinium administration, they are homogeneously avidly enhancing [16–20]. These features are consistent with the vascular nature of LCH. Within the abdomen, a single case of intrahepatic LCH presented as a 5-cm mass within the right lobe of the liver [11]. This demonstrated MRI characteristics similar to those above, with the exception of a T2 hypointense central scar that demonstrated progressive contrast enhancement over time, similar to focal nodular hyperplasia (FNH). Unlike FNH, however, LCH would not be expected to enhance with a hepatocyte specific intravascular contrast agent. This case also further serves to illustrate that larger LCH may contain a central fibrotic component that does not rapidly enhance on CT or MRI, but may fill-in with contrast over time. In formulating the differential diagnosis of a primary retroperitoneal mass, consideration should always be given to malignant entities, which are much more common. A large population based study in the Netherlands found that 80% of non-visceral retroperitoneal neoplasms were malignant, with sarcoma, lymphoma, and carcinomas of unknown primary predominating [21]. Less common considerations include paraganglioma, arteriovenous malformation, and hemangioma. Among primary retroperitoneal hemangiomas, which are extremely rare as a group, the cavernous and venous subtypes are most likely, with only a few documented reports of capillary subtypes, including LCH [22].
Conclusion Although classically a mucocutaneous lesion, the radiologist should be aware that LCH can manifest within the abdomen and pelvis. LCH may be seen within the lumen of the bowel and veins or may present as a lesion within the spinal canal, abdominal viscera, and retroperitoneum. Although limited data regarding the imaging appearance of abdominal LCH are available, their characteristics are thus far consistent with those of LCH seen elsewhere in the body. On CT, they appear as low attenuation lesions with avid peripheral and heterogeneous central enhancement. On MRI, they are T2 hyperintense and demonstrate avid post-contrast enhancement. Further analysis with larger patient population may lead to a more concrete imaging pattern that can help to more reliably distinguished from malignant lesions.
References 1. Patrice SJ, Wiss K, Mulliken JB (1991) Pyogenic granuloma (lobular capillary hemangioma): a clinicopathologic study of 178 cases. Pediatr Dermatol 8(4):267–276 2. Smith SC, Patel RM, Lucas DR, McHugh JB (2013) Sinonasal lobular capillary hemangioma: a clinicopathologic study of 34 cases characterizing potential for local recurrence. Head Neck Pathol 7(2):129–134 3. Mills SE, Cooper PH, Fechner RE (1980) Lobular capillary hemangioma: the underlying lesion of pyogenic granuloma. A study of 73 cases from the oral and nasal mucus membranes. Am J Surg Pathol 4(5):470–479 4. Harris MN, Desai R, Chuang TY, Hood AF, Mirowski GW (2000) Lobular capillary hemangiomas: an epidemiologic report, with emphasis on cutaneous lesions. J Am Acad Dermatol 42(6):1012– 1016 5. Stojsic Z, Brasanac D, Kokai G, et al. (2008) Intestinal intussusception due to a pyogenic granuloma. Turk J Pediatr 50(6):600–603 6. Carmen Gonza´lez-Vela M, Fernando Val-Bernal J, Francisca Garijo M, Garcı´ a-Sua´rez C (2005) Pyogenic granuloma of the sigmoid colon. Ann Diagn Pathol 9(2):106–109 7. van Eeden S, Offerhaus GJ, Morsink FH, et al. (2004) Pyogenic granuloma, an unrecognized cause of gastrointestinal bleeding. Virchows Arch 444(6):590–593 8. Nagoya H, Tanaka S, Tatsuguchi A, et al. (2010) Rare cause of obscure gastrointestinal bleeding due to pyogenic granuloma in the ileum detected by capsule endoscopy and treated by double balloon endoscopy. Dig Endosc 22(1):71–73 9. Val-Bernal JF, Mayorga M, Garcia-Somacarrera E (2012) Pyogenic granuloma of the large intestine: case report and review of reported cases in the adult. Pathol Res Pract 208(11):687–690 10. Pradhan S, Bazan H, Salem R, Gusberg RJ (2008) Intravenous lobular capillary hemangioma originating in the iliac veins: a case report. J Vasc Surg 47(6):1346–1349 11. Takeuchi M, Hara S, Itoh T (2012) A case of intravenous lobular capillary hemangioma of the renal vein mimicking renal cell carcinoma. Pathol Int 62(6):441–443 12. Abaalkhail F, Castonguay M, Driman DK, Parfitt J, Marotta P (2009) Lobular capillary hemangioma of the liver. Hepatobiliary Pancreat Dis Int 8(3):323–325 13. Lee DG, Lee SK, Chang HW, et al. (2010) CT features of lobular capillary hemangioma of the nasal cavity. AJNR Am J Neuroradiol 31(4):749–754 14. Puxeddu R, Berlucchi M, Ledda GP, et al. (2006) Lobular capillary hemangioma of the nasal cavity: a retrospective study on 40 patients. Am J Rhinol 20(4):480–484 15. Cooper PH, McAllister HA, Helwig EB (1979) Intravenous pyogenic granuloma. A study of 18 cases. Am J Surg Pathol 3:221–228
D. Brendel et al.: Retroperitoneal lobular capillary hemangioma
16. Ahn SE, Park JS, Ryu KN, Jin W, Park SY (2013) Intravenous lobular capillary hemangioma occurring in the cephalic vein of a 39-year-old adult. J Clin Ultrasound. doi:10.1002/jcu.22110 17. Maher A (2010) Intravenous lobular capillary hemangioma. Ann Vasc Surg 24(7):951 18. Nyugen BD (2014) Imaging of intravenous lobular capillary hemangioma of azygos vein. Clin Nucl Med 39(1):114–116 19. Andaluz N, Balko MG, Stanek J, Morgan C, Schwetschenau PR (2002) Lobular capillary hemangioma of the spinal cord: case report and review of the literature. J Neurooncol 56(3):261–264
20. Baek HJ, Sun JL, Kil HC, et al. (2010) Subungual tumors: clinicopathologic correlation with US and MR imaging findings. Radiographics 30(6):1621–1636 21. Dalen T, Coebergh JW, Casparie MK, et al. (2001) Soft tissue sarcoma: the predominant primary malignancy in the retroperitoneum. Sarcoma 5(1):5–8 22. Godar M, Yuan Q, Shakya R, Xia Y, Zhang P (2013) Mixed capillary venous retroperitoneal hemangioma. Case Rep Radiol 2013:258352
