Intramuscular Myxoma of the Penis: A Case Report

Intramuscular myxoma (IMM) is a rare benign mesenchymal tumour, characterised by hypocellularity, sparse vascularity, and abundant myxoid stroma, most commonly arising in large skeletal muscles such as the thigh and shoulder girdle. It typically presents as a slow-growing, painless mass in middle-aged adults and is thought to originate from fibroblastic or mesenchymal cells, with GNAS mutations identified in many cases. Although benign, its clinical and radiological features may mimic low-grade myxoid sarcomas, creating diagnostic challenges. Penile involvement is exceptionally rare, with very few cases reported in the literature, and this unusual location often raises concern for malignant soft tissue tumours. Accurate diagnosis, therefore, relies on histopathological evaluation, supported by imaging, to avoid overtreatment. Complete surgical excision is curative, with recurrence being uncommon, and reporting such cases contributes to improved recognition and management of this rare penile tumour. This case concerns a 27-year-old man with a slow-growing mass on the ventral aspect of the distal penile shaft, present for over 10 years, which posed a diagnostic dilemma. However, with the aid of imaging and histology, a confirmation of this rare pathology was made.