Multiple leiomyosarcomatous lesions arising from the mesentery in a young female: An unusual rare case presentation

Rationale: Primary mesenteric leiomyosarcoma is a very rare finding. It is seen predominantly in the seventh decade and is very rare in the young. Fine needle aspiration cytology is the initial diagnostic procedure in soft tissue lesions, followed by excision biopsy. Patient Concerns: Herein, we present a rare case of primary multiple mesenteric leiomyosarcoma in a 19 year old female, who presented with abdominal lump and pain since the last 4 months. Diagnosis: CT scan of abdomen showed multiple large multiloculated masses in the sub-hepatic space and sub-diaphragmatic region, which seemed to be arising from the mesentery. The uterus and cervix were normal. Fine needle aspiration cytology of the mass revealed fascicles of spindled cells with elongated, blunt ended fusiform nuclei admixed with dispersed cells or stripped nuclei. Some cells showed pleomorphism with occasional intranuclear vacuoles. Grossly the resected specimen was multiple nodular, brown, soft to firm, with the largest measuring 8.5x8x2.5 cm and the smallest 2.2x2.2x1 cm in size. On microscopic examination, sections showed fascicular pattern of atypical spindle cells having cigar shaped nuclei showing pleomorphism and eosinophilic fibrillary cytoplasm with 1-2 mitotic figures/10HPF. Immunohistochemistry with SMA showed strong diffuse cytoplasmic positivity and desmin showed mild focal cytoplasmic positivity in the tumor cells. A diagnosis consistent with primary multiple mesenteric leiomyosarcoma was given. Interventions: Wide surgical excision of the mass lesion was performed. The patient was subsequently administered 6 cycles of 5- Fluorouracil based chemotherapy. Outcomes: She is recovering well after 2 month of follow up period. Lessons: Our case will widen the vision of both physicians and pathologists to consider the possibility of primary mesenteric leiomyosarcoma in young females, presenting without any involvement of female genital tract, thus guide in the proper diagnosis and management of such lesions.