Indian Journal of Pathology and Microbiology

CASE REPORT
Year
: 2020  |  Volume : 63  |  Issue : 2  |  Page : 301--304

Spindle cell lipoma, dorsum of hand in a 4 year old child: A rare entity


Parveen Kumar1, Nidhi Mahajan2, Rishabh Jain1, Arti Khatri2,  
1 Department of Pediatric Surgery, Chacha Nehru Bal Chikitsalya, New Delhi, India
2 Department of Pathology, Chacha Nehru Bal Chikitsalya, New Delhi, India

Correspondence Address:
Nidhi Mahajan
Department of Pathology, Chacha Nehru Bal Chikitsalya, New Delhi
India

Abstract

Lipogenic tumors are an uncommon entity in children. There are several variants of lipoma, of which spindle cell lipoma is an extremely rare and accounts for only 1.5% of all lipoma diagnosis. Spindle cell lipoma rarely involves distal extremities. We report a 4-year old boy with swelling over dorsum of hand operated for aesthetic purposes. The report also highlights the salient cytological features, which can help differentiate this entity from other closer mimics on aspiration cytology, guiding the surgeon for appropriate management.



How to cite this article:
Kumar P, Mahajan N, Jain R, Khatri A. Spindle cell lipoma, dorsum of hand in a 4 year old child: A rare entity.Indian J Pathol Microbiol 2020;63:301-304


How to cite this URL:
Kumar P, Mahajan N, Jain R, Khatri A. Spindle cell lipoma, dorsum of hand in a 4 year old child: A rare entity. Indian J Pathol Microbiol [serial online] 2020 [cited 2020 Jul 13 ];63:301-304
Available from: http://www.ijpmonline.org/text.asp?2020/63/2/301/282696


Full Text



 Introduction



Lipogenic masses are common soft tissue lesions (50%) in adults but are a rare occurrence in children.[1] They can appear at ubiquitous sites and show varied areas of histological overlap. Superficial lesions are well defined, encapsulated, and are usually amenable to surgical excision. According to WHO recent Classification of soft tissue tumors, lipomas are categorized into eleven subtypes. Spindle cell lipoma (SCL) is an extremely rare variant, constituting 1.5% of all lipomas.[2] Usually presents as subcutaneous swelling in sites like head and neck, shoulder, upper back, thigh, face and upper arm in middle-aged men. Involvement of the dorsum of the hand and wrist is uncommon. To the best of our knowledge, this is the youngest case reported of SCL on the dorsum of hand.[3] Though histopathology provides the final diagnosis, an attempt should be made to look for clues in cytology and raise suspicion of SCL, as wide local excision is generally curative with no recurrence.

 Case Report



A 4-year-old boy presented to the Department of Pediatric Surgery with complaints of left-hand swelling for 2 years, which was progressively increasing in size. The swelling was not painful however was associated with restricted movements at the wrist owing to the big size of the swelling. On examination, there was a well-defined non-tender superficial solitary swelling measuring 5 cm in diameter, mobile with a firm consistency. There was no fluctuation, erythema, or ulceration [Figure 1]. FNAC was done outside in private and was reported as a benign lesion of adipocytic origin. Parents requested excision on aesthetic grounds. The swelling was subcutaneous, so well excised and sent for histopathological examination [Figure 2]a. Microscopic sections revealed a well encapsulated, moderate to highly cellular lesion, comprising of sheets of mature adipocytes with interspersed mildly pleomorphic spindle cells in a myxoid and fibrous background. Also seen were ropy collagen bundles, lymphocytes, and mast cells [Figure 2]b. No lipoblast was seen [Figure 2]c. No necrosis, mitosis, or nuclear pleomorphism was seen [Figure 2]a. On immunohistochemistry, spindle cells were positive for CD 34 [Figure 2]d. They were S-100 negative (control adipocytes-positive) and focally weak positive for Bcl-2. In view of histopathological features and immunohistochemical findings, a final diagnosis of SCL was given [Figure 2]b. The cytological correlation could not be made as the patient could not retrieve slides from the private lab. The postoperative period was uneventful. There is no recurrence to date.{Figure 1}{Figure 2}

 Discussion



Lipomas account for 50% of all mesenchymal tumors.[1] There are many variants of lipomas of which SCL is relatively rare and accounts for 1.5% of all lipogenic neoplasms.[2] SCL typically presents as a solitary subcutaneous swelling in the shawl area of middle-aged men (40–70 years). Rare atypical locations include the face, upper arm, breast, buttocks, orbit, oral mucosa, perineum, and inguinal region.[3],[4] This case is a toddler who presented with a swelling on the dorsum of the left hand; age and site both being uncommon. This site has not been reported in the pediatric age group so far. [Table 1] summarizes all the cases of SCL arising in hand and wrist.{Table 1}

Radiological investigations like Doppler Ultrasound or Magnetic Resonance Imaging (MRI) may be helpful in many cases. The appearance on the latter may vary from nonfatty, heterogeneous to homogenous lipoma-like depending upon the proportion of mature fat. Hence, these investigations are useful in defining the extent of the disease but not providing a specific diagnosis. Radiology was not performed in our case as the swelling was superficial in location, mobile and also amenable to complete excision.

Histopathology is the gold standard for establishing the diagnosis, though fine needle aspiration cytology can give clues. Typical lipomas do not pose much diagnostic difficulty on cytology, yet the unusual variants including SCL may be mistaken for a grave diagnosis like liposarcomas or other spindle cell mimics like schwannoma, neurofibroma, lipoblastoma, angiolipoma, dermatofibroma, solitary fibrous tumor, fibrous hamartoma of infancy, and myxoma.[4],[5] Though the cytological features of SCL are less discussed in the literature, one should be aware of them to propose a diagnosis. Cytological features described are varying proportions of bland-looking spindle cells, adipocytes, and variably sized collagen bundles and presence of mast cells. There is minimal nuclear pleomorphism and the background may show myxoid change and no necrosis. On histopathology, SCL shows all the three components: mature adipocytes, monomorphic spindle cells, and thick collagen bundles in variable proportions. Spindle cells are arranged in short fascicles and sometimes may show nuclear palisading. Hemangiopericytic vascular pattern may be seen. Sometimes, a prominent myxoid matrix may be seen. Mast cells and lymphocytes are a frequent finding and an important clue to the diagnosis. No mitosis/storiform pattern/necrosis/lipoblasts seen.

There is a wide list of differential diagnosis of SCL more so on cytology than histology [Table 2]. The closer differentials which also express CD 34 are angiolipomas, neurofibroma, SFT, mammary type myofibroblastoma and lipomatous hemangiopericytoma. These entities can be differentiated from SCL on the basis of age of clinical, cytological, histopathological features (highlighted in [Table 2]). SCL was first described in the literature by Enzinger and Harvey in 1975.5 They emphasized its differentiation from liposarcoma (LPS) by the absence of the hallmark cell, lipoblast. They noticed that SCL is more superficial than LPS. Comunoglu et al. noted CD34 positivity as a characteristic feature of SCL, which is rarely seen in liposarcoma.[6] Uehara et al. went one step ahead and studied the molecular signature of these tumors with monoallelic 13q14 deletion and demonstrated a link between FOXO1 status and p38MAPK Pathway.[7],[8]{Table 2}

The management of SCL includes surgical excision with adequate margins. The overall prognosis of this benign entity is good with a very low recurrence rate.[5]

 Conclusion



Spindle cell lipoma can be seen in childhood and can affect rare sites like the hand. Increased awareness of this entity amongst pediatric surgeons and updating cytological and histopathological features amongst pathologists is of paramount importance in reaching a correct diagnosis. Appropriate management of these cases involves a wide local excision with removal of the entire capsule to prevent a recurrence.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Skinner H, Mcmahon P. Current Diagnosis and Treatment in Orthopedics. 5th ed. New York, NY, USA: McGraw Hill Education; 2014.
2Fletcher CDM, Martin-Bates E. Spindle cell lipoma: A clinicopathologic study with some original observations. Histopathology 1987;11:803-17.
3Akaike K, Suehara Y, Takagi T, Kaneko K, Yamashita A, Yao T, et al. Spindle cell lipoma of the wrist; occurring in a distinctly rare location: A case report with review of literature. Int J Clin Exp Pathol 2015;8:3299-303.
4Ud Din N, Zhang P, Sukov WR, Sattler CA, Jenkins SM, Doyle LA, et al. Spindle cell lipomas arising at atypical locations. Am J Clin Pathol 2016;146:487-95.
5Enzinger FM, Harvey DA. Spindle cell lipoma. Cancer 1975;36:1852-9.
6Comunoglu N, Comunoglu C, Ekici AI, Ozkan F, Dervişoglu S. Spindle cell lipoma. Pol J Pathol 2007;58:7-11.
7Chrisinger JS. Update on Lipomatous Tumors with Emphasis on Emerging Entities, Unusual Anatomic Sites, and Variant Histologic Patterns. Surg Pathol Clinics 2019;12:21-33.
8Uehara K, Ikehara F, Shibuya R, Nakazato I, Oshiro M, Kiyuna M, et al. Molecular signature of tumors with monoallelic 13q14 deletion: A case series of spindle cell lipoma and genetically-related tumors demonstrating a link between FOXO1 status and p38 MAPK pathway. Pathol Oncol Res 2018;24:861-9.
9Shogo E, Ikuko O, Kiichi I, Yoshinori S, Tomomi K. Spindle cell lipoma of the thumb. Plast Reconstr Surg Glob Open 2018;6:1671.
10Goldblum JR, Folpe AL, Weiss W, Enzinger FM. Enzinger and Weiss' Soft Tissue Tumors (Sixth Edition). Philadelphia, PA: Elsevier Saunders; 2014.