592017
research-article2015
IJSXXX10.1177/1066896915592017International Journal of Surgical PathologyRubin et al
Case Report
Novel Pathologic Finding of Digital Soft Tissue Chondroma in a Child: A Case Report and Review of Literature
International Journal of Surgical Pathology 1–4 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915592017 ijs.sagepub.com
Todd Rubin, MD1, Andrew Schwartz, BA1, Eric Fornari, MD1, and Jacob Schulz, MD1
Abstract Unlike osteochondromata that develop in the hand, soft tissue chondromata (STC) devoid of bone and tendinous attachments are exceedingly rare. They have been described in adult patients of middle age, though have not been previously reported in the pediatric population. We report the case of a 9-year-old female that presented with a tender digital mass 6 months following a minor hand injury. After an extensive workup, the mass was surgically excised and diagnosed as an STC. Our case is the first to identify a digital STC in a pediatric patient and expands on the pathologic differential diagnosis. While the true incidence in the pediatric population is unknown, STC should be included in the differential diagnosis when any patient, adult or child, presents with a digital mass. Keywords soft tissue chondroma, chondroma, osteochondroma, enchondroma, pediatric hand mass
Introduction Soft tissue chondromata (STC) of the digit/hand are extremely rare and have only been reported in the adult population. They are differentiated from other chondromata subtypes by their lack of bony or periosteal attachments. While the pathophysiology of such lesions is somewhat controversial, it is important to recognize how these unfamiliar growths present in order to differentiate from malignant tumors. In response to the presentation and findings of our patient, we conducted a literature review using the PubMed database through July 2014. Key words used were soft tissue chondroma, enchondroma, osteochondroma, hand, pediatric and child in various associations. Articles pertaining to STC, pediatric STC, and chondromata of the hand and/or upper extremity were evaluated for relevance. Six articles were identified using key words “soft tissue chondroma” and “pediatric.” One case report of a subungual soft tissue chondroma in a child was identified.1 However, our case is the first reported in the literature of a subcutaneous digital STC within the pediatric population.
discovered several weeks after being bitten by one of her younger siblings. The bite did not penetrate the skin and medical attention was not obtained. The growth was intermittently tender with subjective numbness on the radial side of the index finger. The patient denied local drainage or warmth. There was no history of fevers or chills during the 6-month period. All other past medical history was unremarkable. Physical examination demonstrated a mass just proximal to the PIP joint of the left index finger with moderate skin puckering at the flexion crease (Figure 1). Palpation revealed that the mass was mobile, tender, and perhaps adherent to the flexor mechanism. There was full range of motion of all joints of the finger, though mass effect prevented the patient from making a tight fist. Neurovascular examination was within normal limits. Plain films of the left index finger showed nonspecific soft tissue swelling on the volar surface of the proximal phalanx without obvious osseous involvement (Figure 2A and B). Ultrasound was obtained and revealed an avascular, heterogeneous soft tissue mass. Magnetic resonance imaging 1
Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
Case Report A 9-year-old female initially presented with a 6-month history of a volar mass on the proximal interphalangeal (PIP) joint of the left index finger. Per the patient, the mass was
Corresponding Author: Todd Rubin, Montefiore Medical Center/Albert Einstein College of Medicine, 1250 Waters Place, Bronx, NY 10461-2723, USA. Email: [email protected]
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
2
International Journal of Surgical Pathology benign, mature chondrocytes, absent of cellular atypia or mitoses. The tumor was remarkably well demarcated, with clear absence of any skeletal component or subcutaneous/ cutaneous tissue interruption in the sample’s borders. Aside from the classic chondrocyte, there were no other cell types in the tissue sample (ie, epithelial cells, glandular cells, collagen fibers, myocytes, or osteocytes). The myxoid matrix was uniform in nature without areas of necrosis. The background of the myxoid matrix consisted of both displaced subdermal and dermal tissue components (Figure 3B and C). On later follow-up, the incision was well healed and the mass had not recurred. She reported full sensation of the affected digit and demonstrated the ability to make a tight fist with all fingers.
Discussion
Figure 1. A) AP and B) lateral photographs of left index finger. Mass at black arrow.
demonstrated a well-demarcated mass that displaced the flexor tendon without tendinous or bony invasion. The mass was of low-to-intermediate signal density on T1-weighted imaging (with and without contrast), and high signal density on T2-weighted imaging (Figure 2C and D). These diagnostic findings are consistent with prior descriptions of STC.2 Six months after initial presentation, the patient reported increased tenderness and enlargement of the mass. Given the progression of symptoms and limited use of digit, the decision was made to proceed with surgical excision of the mass. A volar oblique incision was made overlying the mass, in the event that an extensile approach was required. The mass was noted to abut, but not adhere to, the flexor digitorum profundus tendon sheath, and easily separated with blunt dissection. On gross appearance, the mass was white-gray in color and had a rubbery texture. The mass measured 1.3 × 0.9 × 0.6 cm (Figure 3A) and was well circumscribed. On histopathologic evaluation, the tissue consisted of a hypocellular myxoid matrix with nests of
Chondromata are frequently diagnosed in the upper extremity and make up 69% of all hand tumors.3 Subtypes include enchondroma, periosteal chondroma, and soft tissue chondroma. The most common is the enchondroma, often diagnosed in the fourth and fifth decades, with an average age of incidence of 36.8 years.3 They typically form in the medulla of the long bones of the hand, three fourths of which are intraphalangeal.3 A periosteal chondroma is a cartilaginous mass derived from the surface of long bones that extends into the metaphyseal region of bone. They are generally diagnosed at an average age of 22.8 years and account for only 1.9% of all hand tumors.3,4 STC are among the rarest tumors of the hand and present at an average age of 42.1 years.5,6 Before this case, there were no known cases in the pediatric population, making pathologic identification a great challenge. The pathologic differential diagnosis includes typical chondromata, extension of primary osseous tumors with chondroid metaplasia, hamartomatous growth, fibromata, and poorly differentiated focal metastases of chondrosarcoma or osteochondroma.2 Appropriate radiographic and histologic exams are necessary to confirm the diagnosis. On clinical exam, STC are subcutaneous, dermal, or subdermal in nature and are distinct from the surrounding tissue. Temporally, they have a more insidious development than rapidly doubling sarcomata.2 On gross inspection, they lack periosteal and cortical attachments and usually develop outside a tendon sheath and/or joint capsule.7 They often measure less than 3 cm in greatest dimension and have a rubbery, firm texture. Histopathologic examination is critical in establishing the diagnosis. Initially, the tumor’s local anatomy is critical in raising suspicion: the mass should have subcutaneous, subdermal, or dermal involvement, with clear margins from local periosteal and tendious tissue. This allows for distinction from dermal or enchondromata. The unique
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
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Rubin et al
Figure 2. A) PA and B) lateral radiographs of the left index finger. C) Sagittal and D) axial T1-weighted MRI of the left index finger.
Figure 3. A) Surgically resected mass B) Uniform cartilaginous neoplasm; H&E stain, 200x magnification. C) Benign chondrocytes; H&E stain, 400x magnification.
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
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International Journal of Surgical Pathology
architecture of an STC includes lobules of chondrocytes in a matrix devoid of necrosis, epithelial cells, adenomatous tissue, collagen, or other metaplastic/anaplastic transformations.2 Immature chondroblasts and mature chondrocytes surround a hyaline myxoid matrix and lack significant atypia. The absence of nuclear mitoses further helps differentiate benign immature cells from malignant atypical cells.2 In addition, immunohistochemistry can aid in the diagnosis. STC stain positively for S-100 protein and vimentin filaments and importantly do not stain for epithelial or myoepithelial markers.2 The pathophysiology of STC is still currently debated, and a review of the literature reflects two theories. One suggests that they originate from synovial tissue as a result of a developmental defect, whereas another suggests they develop as a result of a metaplastic event.8 No specific genetic predisposition has been reported; rather, the literature supports a seemingly random, haphazard collection of translocations, structural changes, and deletions on a variety of different chromosomes.9 Given the history of trauma to the digit in our patient, it is possible that the mass developed in response to the tissue healing process, which resulted in a cell differentiation error and/or growth dysregulation. There is no published record of malignant transformation of an STC of the hand; however, surgical excision minimizes mass effect, discomfort, and the possibility of functional compromise. Removal may also help prevent local recurrence of the tumor. In summary, this case demonstrates a rare finding of a digital STC in a pediatric patient and expands on the pathologic differential diagnosis of any digital mass that presents in either the pediatric or adult population. This novel case emphasizes the need for an interdisciplinary approach between the surgeon and pathologist in order to render a timely and accurate diagnosis. Acknowledgments The authors thank Dr Esperanza Villanueva-Siles, pathologist at Montefiore Medical Center/Albert Einstein College of
Medicine, for the preparation of the pathology images of this patient’s biopsy.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Eun YS, Kim MR, Cho BK, Yoo G, Park HJ. Subungual soft tissue chondroma with nail deformity in a child. Pediatr Dermatol. 2015;32:132-134. 2. Gungor S, Kamali G, Canat D, Gokdemir G. Soft tissue chondroma of the index finger: clinical, histological and radiological findings in a unique case. Dermatol Online J. 2013;19:18176. 3. Simon MJ, Pogoda P, Hovelborn F, et al. Incidence, histopathologic analysis and distribution of tumours of the hand. BMC Musculoskel Disord. 2014;15:182. 4. Kosaka H, Nishio J, Matsunaga T, Aoki M, Iwasaki H, Naito M. Imaging features of periosteal chondroma manifesting as a subcutaneous mass in the index finger. Case Rep Orthop. 2014;2014:763480. 5. Hondar Wu HT, Chen W, Lee O, Chang CY. Imaging and pathological correlation of soft-tissue chondroma: a serial fivecase study and literature review. Clin Imaging. 2006;30:32-36. 6. Humphreys S, Pambakian H, McKee PH, Fletcher CD. Soft tissue chondroma—a study of 15 tumours. Histopathology. 1986;10:147-159. 7. Bansal M, Goldman AB, DiCarlo EF, McCormack R. Soft tissue chondromas: diagnosis and differential diagnosis. Skeletal Radiol. 1993;22:309-315. 8. Zlatkin MB, Lander PH, Begin LR, Hadjipavlou A. Softtissue chondromas. AJR. Am J Roentgenol. 1985;144: 1263-1267. 9. Sakai Junior N, Abe KT, Formigli LM, et al. Cytogenetic findings in 14 benign cartilaginous neoplasms. Cancer Genet. 2011;204:180-186.
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
research-article2015
IJSXXX10.1177/1066896915592017International Journal of Surgical PathologyRubin et al
Case Report
Novel Pathologic Finding of Digital Soft Tissue Chondroma in a Child: A Case Report and Review of Literature
International Journal of Surgical Pathology 1–4 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915592017 ijs.sagepub.com
Todd Rubin, MD1, Andrew Schwartz, BA1, Eric Fornari, MD1, and Jacob Schulz, MD1
Abstract Unlike osteochondromata that develop in the hand, soft tissue chondromata (STC) devoid of bone and tendinous attachments are exceedingly rare. They have been described in adult patients of middle age, though have not been previously reported in the pediatric population. We report the case of a 9-year-old female that presented with a tender digital mass 6 months following a minor hand injury. After an extensive workup, the mass was surgically excised and diagnosed as an STC. Our case is the first to identify a digital STC in a pediatric patient and expands on the pathologic differential diagnosis. While the true incidence in the pediatric population is unknown, STC should be included in the differential diagnosis when any patient, adult or child, presents with a digital mass. Keywords soft tissue chondroma, chondroma, osteochondroma, enchondroma, pediatric hand mass
Introduction Soft tissue chondromata (STC) of the digit/hand are extremely rare and have only been reported in the adult population. They are differentiated from other chondromata subtypes by their lack of bony or periosteal attachments. While the pathophysiology of such lesions is somewhat controversial, it is important to recognize how these unfamiliar growths present in order to differentiate from malignant tumors. In response to the presentation and findings of our patient, we conducted a literature review using the PubMed database through July 2014. Key words used were soft tissue chondroma, enchondroma, osteochondroma, hand, pediatric and child in various associations. Articles pertaining to STC, pediatric STC, and chondromata of the hand and/or upper extremity were evaluated for relevance. Six articles were identified using key words “soft tissue chondroma” and “pediatric.” One case report of a subungual soft tissue chondroma in a child was identified.1 However, our case is the first reported in the literature of a subcutaneous digital STC within the pediatric population.
discovered several weeks after being bitten by one of her younger siblings. The bite did not penetrate the skin and medical attention was not obtained. The growth was intermittently tender with subjective numbness on the radial side of the index finger. The patient denied local drainage or warmth. There was no history of fevers or chills during the 6-month period. All other past medical history was unremarkable. Physical examination demonstrated a mass just proximal to the PIP joint of the left index finger with moderate skin puckering at the flexion crease (Figure 1). Palpation revealed that the mass was mobile, tender, and perhaps adherent to the flexor mechanism. There was full range of motion of all joints of the finger, though mass effect prevented the patient from making a tight fist. Neurovascular examination was within normal limits. Plain films of the left index finger showed nonspecific soft tissue swelling on the volar surface of the proximal phalanx without obvious osseous involvement (Figure 2A and B). Ultrasound was obtained and revealed an avascular, heterogeneous soft tissue mass. Magnetic resonance imaging 1
Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
Case Report A 9-year-old female initially presented with a 6-month history of a volar mass on the proximal interphalangeal (PIP) joint of the left index finger. Per the patient, the mass was
Corresponding Author: Todd Rubin, Montefiore Medical Center/Albert Einstein College of Medicine, 1250 Waters Place, Bronx, NY 10461-2723, USA. Email: [email protected]
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
2
International Journal of Surgical Pathology benign, mature chondrocytes, absent of cellular atypia or mitoses. The tumor was remarkably well demarcated, with clear absence of any skeletal component or subcutaneous/ cutaneous tissue interruption in the sample’s borders. Aside from the classic chondrocyte, there were no other cell types in the tissue sample (ie, epithelial cells, glandular cells, collagen fibers, myocytes, or osteocytes). The myxoid matrix was uniform in nature without areas of necrosis. The background of the myxoid matrix consisted of both displaced subdermal and dermal tissue components (Figure 3B and C). On later follow-up, the incision was well healed and the mass had not recurred. She reported full sensation of the affected digit and demonstrated the ability to make a tight fist with all fingers.
Discussion
Figure 1. A) AP and B) lateral photographs of left index finger. Mass at black arrow.
demonstrated a well-demarcated mass that displaced the flexor tendon without tendinous or bony invasion. The mass was of low-to-intermediate signal density on T1-weighted imaging (with and without contrast), and high signal density on T2-weighted imaging (Figure 2C and D). These diagnostic findings are consistent with prior descriptions of STC.2 Six months after initial presentation, the patient reported increased tenderness and enlargement of the mass. Given the progression of symptoms and limited use of digit, the decision was made to proceed with surgical excision of the mass. A volar oblique incision was made overlying the mass, in the event that an extensile approach was required. The mass was noted to abut, but not adhere to, the flexor digitorum profundus tendon sheath, and easily separated with blunt dissection. On gross appearance, the mass was white-gray in color and had a rubbery texture. The mass measured 1.3 × 0.9 × 0.6 cm (Figure 3A) and was well circumscribed. On histopathologic evaluation, the tissue consisted of a hypocellular myxoid matrix with nests of
Chondromata are frequently diagnosed in the upper extremity and make up 69% of all hand tumors.3 Subtypes include enchondroma, periosteal chondroma, and soft tissue chondroma. The most common is the enchondroma, often diagnosed in the fourth and fifth decades, with an average age of incidence of 36.8 years.3 They typically form in the medulla of the long bones of the hand, three fourths of which are intraphalangeal.3 A periosteal chondroma is a cartilaginous mass derived from the surface of long bones that extends into the metaphyseal region of bone. They are generally diagnosed at an average age of 22.8 years and account for only 1.9% of all hand tumors.3,4 STC are among the rarest tumors of the hand and present at an average age of 42.1 years.5,6 Before this case, there were no known cases in the pediatric population, making pathologic identification a great challenge. The pathologic differential diagnosis includes typical chondromata, extension of primary osseous tumors with chondroid metaplasia, hamartomatous growth, fibromata, and poorly differentiated focal metastases of chondrosarcoma or osteochondroma.2 Appropriate radiographic and histologic exams are necessary to confirm the diagnosis. On clinical exam, STC are subcutaneous, dermal, or subdermal in nature and are distinct from the surrounding tissue. Temporally, they have a more insidious development than rapidly doubling sarcomata.2 On gross inspection, they lack periosteal and cortical attachments and usually develop outside a tendon sheath and/or joint capsule.7 They often measure less than 3 cm in greatest dimension and have a rubbery, firm texture. Histopathologic examination is critical in establishing the diagnosis. Initially, the tumor’s local anatomy is critical in raising suspicion: the mass should have subcutaneous, subdermal, or dermal involvement, with clear margins from local periosteal and tendious tissue. This allows for distinction from dermal or enchondromata. The unique
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
3
Rubin et al
Figure 2. A) PA and B) lateral radiographs of the left index finger. C) Sagittal and D) axial T1-weighted MRI of the left index finger.
Figure 3. A) Surgically resected mass B) Uniform cartilaginous neoplasm; H&E stain, 200x magnification. C) Benign chondrocytes; H&E stain, 400x magnification.
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
4
International Journal of Surgical Pathology
architecture of an STC includes lobules of chondrocytes in a matrix devoid of necrosis, epithelial cells, adenomatous tissue, collagen, or other metaplastic/anaplastic transformations.2 Immature chondroblasts and mature chondrocytes surround a hyaline myxoid matrix and lack significant atypia. The absence of nuclear mitoses further helps differentiate benign immature cells from malignant atypical cells.2 In addition, immunohistochemistry can aid in the diagnosis. STC stain positively for S-100 protein and vimentin filaments and importantly do not stain for epithelial or myoepithelial markers.2 The pathophysiology of STC is still currently debated, and a review of the literature reflects two theories. One suggests that they originate from synovial tissue as a result of a developmental defect, whereas another suggests they develop as a result of a metaplastic event.8 No specific genetic predisposition has been reported; rather, the literature supports a seemingly random, haphazard collection of translocations, structural changes, and deletions on a variety of different chromosomes.9 Given the history of trauma to the digit in our patient, it is possible that the mass developed in response to the tissue healing process, which resulted in a cell differentiation error and/or growth dysregulation. There is no published record of malignant transformation of an STC of the hand; however, surgical excision minimizes mass effect, discomfort, and the possibility of functional compromise. Removal may also help prevent local recurrence of the tumor. In summary, this case demonstrates a rare finding of a digital STC in a pediatric patient and expands on the pathologic differential diagnosis of any digital mass that presents in either the pediatric or adult population. This novel case emphasizes the need for an interdisciplinary approach between the surgeon and pathologist in order to render a timely and accurate diagnosis. Acknowledgments The authors thank Dr Esperanza Villanueva-Siles, pathologist at Montefiore Medical Center/Albert Einstein College of
Medicine, for the preparation of the pathology images of this patient’s biopsy.
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Eun YS, Kim MR, Cho BK, Yoo G, Park HJ. Subungual soft tissue chondroma with nail deformity in a child. Pediatr Dermatol. 2015;32:132-134. 2. Gungor S, Kamali G, Canat D, Gokdemir G. Soft tissue chondroma of the index finger: clinical, histological and radiological findings in a unique case. Dermatol Online J. 2013;19:18176. 3. Simon MJ, Pogoda P, Hovelborn F, et al. Incidence, histopathologic analysis and distribution of tumours of the hand. BMC Musculoskel Disord. 2014;15:182. 4. Kosaka H, Nishio J, Matsunaga T, Aoki M, Iwasaki H, Naito M. Imaging features of periosteal chondroma manifesting as a subcutaneous mass in the index finger. Case Rep Orthop. 2014;2014:763480. 5. Hondar Wu HT, Chen W, Lee O, Chang CY. Imaging and pathological correlation of soft-tissue chondroma: a serial fivecase study and literature review. Clin Imaging. 2006;30:32-36. 6. Humphreys S, Pambakian H, McKee PH, Fletcher CD. Soft tissue chondroma—a study of 15 tumours. Histopathology. 1986;10:147-159. 7. Bansal M, Goldman AB, DiCarlo EF, McCormack R. Soft tissue chondromas: diagnosis and differential diagnosis. Skeletal Radiol. 1993;22:309-315. 8. Zlatkin MB, Lander PH, Begin LR, Hadjipavlou A. Softtissue chondromas. AJR. Am J Roentgenol. 1985;144: 1263-1267. 9. Sakai Junior N, Abe KT, Formigli LM, et al. Cytogenetic findings in 14 benign cartilaginous neoplasms. Cancer Genet. 2011;204:180-186.
Downloaded from ijs.sagepub.com at FLORIDA INTERNATIONAL UNIV on August 27, 2015
