Microscopic uterine lymphangioleiomyomatosis perivascular epithelioid cell neoplasm: a case report with the earliest manifestation of this enigmatic neoplasm.

Lymphangioleiomyomatosis (LAM) is part of a family of lesions collectively known as perivascular epithelioid cell neoplasms (PEComas). Though these lesions are comprised of histologically and immunohistochemically distinctive perivascular epithelioid cells, their diagnosis is controversial and some investigators question their existence entirely. We present a unique case of perhaps the earliest microscopic example of a LAM PEComa in the uterine myometrium, and contrast its features to that of intravascular adenomyosis, intravascular endometrial stromal sarcoma, and intravascular leiomyoma.