NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810 Volume 3│Issue 2│Apr – June 2013 Page 193 CASE REPORT CLEAR CELL SARCOMA OF GLUTEAL REGION MALIGNANT MELANOMA OF SOFT PARTS Haren V. Oza 1 , Jignasa N Bhalodia 2 , Kinara A. Patel 3 , Palak J. Modi 4 Authors’ Affiliation: 1 Professor & Head; 2 Associate Professor; 3 Assistant Professor; 4 Tutor, Department of Pathology, G.M.E.R.S. Medical College, Sola, Ahmedabad Correspondence: Dr. Haren V. Oza, Email: drharenoza@yahoo.co.in ABSTRACT Clear cell sarcoma (CCS) is described as variant of sarcoma characterized by prominent clear cells showing features similar to malignant melanoma of soft parts. This neoplasm was first described by Dr. Franz m. Enzinger. Primary CCS usually arises in deeper soft tissues, in association with fascia, tendons, or aponeuroses. Clear cell sarcoma (CCS) is a rare malignant tumor with a propensity for slow progressive invasion. It is a tumor derived from Melanoblast like cell. They occur most commonly in the extremities, with a predilection for young females. Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts) and conventional malignant melanoma may demonstrate significant morphologic overlap at the light microscopic and ultra structural level. The tumor is very rare and can pose clinical challenges in early diagnosis. This case report demonstrates an unusual site of occurrence for clear cell sarcoma. Key words: Clear cell sarcoma (C C S), Malignant melanoma (M M) of soft part, gluteal region. INTRODUCTION Described in 1968 by Enzinger, clear cell sarcoma has become a well-accepted clinicopathologic entity. Clear cell sarcoma (CCS) is a rare neoplasm with a difficult clinical and histological differential diagnosis. The entity of CCS is also known as malignant melanoma of soft parts and it represents about 1% of soft tissue tumors. Because of the presence of melanin, pre-melanosomes, S-100 protein and the tendency for regional nodal metastasis, it has been suggested that this entity may be considered as malignant melanoma rather than soft tissue sarcoma. Although it produces melanin, it differs from the conventional melanoma in several important aspects. It is a deeply situated tumor that is nearly always intimately associated with tendons and aponeuroses. It lacks junctional changes and rarely involves epidermis. Cytogenetic analysis showing characteristic translocation t(12;22) (q13;q12) has been considered pathognomonic for CCS. This translocation has been observed in neither cutaneous Malignant Melanoma. This genetic translocation demonstrates that CCS resembles MM but has a different pathogenesis. Although the term malignant melanoma of soft parts is used as synonym for this tumor, it is important that this lesion not loosely be considered malignant melanoma but rather a unique lesion. 1 Clinically, most cases present as a slowly progressive, painless mass on the lower limbs. The tumor increases in size followed by metastatic dissemination to lymph nodes and lungs. Malignant melanoma (MM) is the most important differential diagnosis to exclude. CASE REPORT A Twenty three years old woman presented with fever and discharge from wound over right buttock near perianal region since one month. Physical examination revealed right perianal lesion with discharge was present giving clinical impression of perianal abscess or fistula. There was no change in bowel, bladder habits. On systemic examination RS, CVS, AS, CNS were normal. No organomegaly or lymphadenopathy found. Routine investigations show Hb. 9.0 gm%,Total count 7800/ cumm, platelet count 3,90,000/cumm, Renal function test and Liver function test were normal. She was treated with wide local excision & tissue was submitted for histopathological examination. The gross specimen measured 6 cm. in aggregate with skin covered fibro fatty soft tissue. On cut section it shows lobulated mass with dark brown patchy areas seen. Microscopic examination on H & E stain revealed there are round to polyhedral cells arranged in groups, nests, and trabecular formation. The tumor cells are separated by fibrous septa. The cells are having round nucleus with nucleoli and minimal cytological atypia with clear cytoplasm. (FIG 1). There are brownish pigment laden tumor cells and macrophages present in the deeper tissue. (FIG2). No junctional activity seen. At places tumor cells also