Apoplectic leiomyomas of the uterus. A clinicopathologic study of five distinctive hemorrhagic leiomyomas associated with oral contraceptive usage.

Five histologically distinctive uterine smooth muscle neoplasms with multifocal hemorrhages termed apoplectic leiomyomas were studied. All patients were found to have been taking a combination-type oral contraceptive hormonal medication containing the progestin norethindrone for 2-4 years. Abdominal pain was the most frequent presenting symptom. The tumors ranged in size from about 1.1 to 4 cm and had multiple gross hemorrhages. Microscopically, they were characterized by stellate zones of recent hemorrhage within nodules of hypercellular smooth muscle. Coagulative necrosis, as seen in "red degeneration," was inconspicuous. Mitotic figures were sparse, not exceeding 2/10 HPF, and were mostly located in the perihemorrhagic areas. Abnormal blood vessels of various sizes were frequent and may have led to the hemorrhages. No recurrences developed up to 12 years after operation. A causal relationship between apoplectic leiomyomas and oral contraceptive usage is strongly suggested. Recognition of their distinctive pathologic features will prevent misdiagnosis as leiomyosarcoma.