MICROSCOPIC DESCRIPTION: Sections show fragment of skeletal muscle together with fragments of dense fibrous tissue and loose myxoid fibrous tissue. The cells in the myxoid tissue are spindled or stellate, with bland oval nuclei. No mitoses are seen and there is no necrosis. In immunostains, the spindle cells are CD34+, smA+ (patchy), S100-. There is no nuclear staining for Ki67 .

DIAGNOSIS: Core biopsy of right thigh mass: Paucicellular myxoid tissue with features consistent with an intramuscular myxoma.

The patient underwent to complete local excision. The final pathology report confirmed an intramuscular myxoma with no lymphovascular or perineural invasion and showed complete excision of the thigh skin scar and carbon tract (consistent with previous biopsy site).  

Case courtesy of Associate Professor Pramit Phal and Dr Beng Lim from the RMH Radiology Department.