Myxoid Leiomyosarcoma of the Uterus -A Case Report with Light Microscopic and Ultrastructural Appraisal

Abstract

A case of an infiltrating myxopolypoid tumor of the uterus is presented. Histologically, the tumor revealed spindle-shaped cells with mitotic counts ranging between 1-4/hpf, myxoid stroma, and multinucleated giant cells mimicking syncitial giant cells of pregnancy trophoblast. Conventional light microscopic methods failed to establish the histogenesis of the tumor. At the ultrastructural level the tumor showed three main cellular components; myoblasts, myofibroblasts and collagen-producing fibroblasts. On the basis of light microscopic and electron microscopic findings, the tumor was labelled myxoid leiomyosarcoma. This variant of leiomyosarcoma is rare. This is the seventh case reported in the international literature.

Immunohistochemistry (Ki‐67 and p53) as a tool in determining malignancy in smooth muscle neoplasms (exemplified by a myxoid leiomyosarcoma of the uterus)

“…Myxoid leiomyosarcoma of the uterus is a rare neoplasm: only 16 cases (1, 3,6,8,12,13,[18][19][20] have previously been reported in the English literature. It has a highly malignant course although the microscopic criteria for malignancy in smooth muscle neoplasms (e.g.…”

Myxoid leiomyosarcoma of the uterus

“…Since then, a number of individual case reports of uterine MLMSs and small series have been published (Table 3). 2–23 Occurring in a wide age range (20–86 years, with a median of 57 years), a majority of patients present with uterine bleeding, uterine mass, or abdominal pain.…”

“…The usual clues for malignancy for smooth muscle tumours, such as prominent nuclear pleomorphism and high mitotic index, are often absent; furthermore, the presence of TCN is quite difficult to ascertain in MLMS. Among the approximately 50 reported cases, 2–23 some have relied on tumour recurrence to confirm the diagnosis of malignancy for myxoid smooth muscle tumours. Interestingly, in the original series reported by King et al 2 it was noted that all tumours had infiltrative margins, and two also invaded lumens of large veins.…”