Diagnostic surprise on IHC: A rare case of intramuscular DLBCL in thigh region mimicking sarcoma

Abstract

Soft tissue sarcomas are broad group of malignant tumours that arise in tissues like fat, muscle, nerves, fibrous tissue and blood vessels. A variety of non mesenchymal neoplasms like sarcomatoid carcinomas, melanomas and extranodal lymphomas may also mimic soft tissue sarcoma. Diffuse Large BCell Lymphoma is the most common type of Non HodgkinsLymphoma accounting for around 30-40% of cases.DLBCL involving skeletal muscle is extremely rare accounting approximately <1% of the cases with most of the cases reported in the lower extremity involving calf and thigh region.Here we report a case of DLBCL of the left thigh mass in 60 years old male which was initially thought to be a sarcoma based on clinical findings and imaging, but was later diagnosed to be DLBCL after surgical excision of the mass with the help of histopathology and immunohistochemistry.