Primary Uterine Alveolar Rhabdomyosarcoma: A Rare Entity

Primary alveolar rhabdomyosarcoma arising in the uterus is an extremely uncommon entity and is often a diagnosis of exclusion. Rapid uterine enlargement and per-vaginal bleeding are the commonest clinical presentations of this tumour. In the absence of such symptoms, diagnostic delays are not uncommon. An elderly woman presented with abdominal distention and weight loss of 12 months duration with no prior gynaecological symptoms. Imaging showed a large, heterogeneous uterine mass reaching up to the epigastrium, with no evidence of distant metastases. An image-guided biopsy suggested a high-grade sarcoma. She underwent standard surgical staging, which included total abdominal hysterectomy, bilateral salphingo-oophorectomy and pelvic lymphadenectomy. The histopathological examination and immunohistochemical studies established the diagnosis of a primary uterine rhabdomyosarcoma, which was later confirmed to be of the alveolar subtype by a positive translocation of the FOXO1 gene on fluorescence in situ hybridization. Primary uterine alveolar rhabdomyosarcoma is rare in adults. The immunohistochemistry and translocation studies are important to establish the diagnosis, especially when presenting symptoms are non -specific.