Apoplectic leiomyomas of the uterus

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/ 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. Leiomyomas of the uterus are extremely common tumors that occur in 20-25% of adult women.(13) They may exhibit a variety of histologic appearances and are subject to numerous types of secondary degenerative changes. Considerable attention has been directed to such variants as cellular leiomyoma and pleomorphic (“bizarre”) leiomyoma and their distinction from leiomyosarcoma. The effects of oral contraceptives and progestational hormones on uterine leiomyomas have also been studied.(1, 6, 7, 8, 9, 14, 16) Although several alterations have been identified in myomas removed from women taking such hormonal preparations, the presence of cellular atypia has been most disconcerting. A definite relation between oral contraceptive hormones and atypical myomas, however, remains to be demonstrated.(8) Acute hemorrhage or hemorrhagic necrosis of leiomyomas has also been described in women taking oral contraceptive medications or receiving progestin therapy but has only rarely been documented. (4, 7) We have studied five cases of a histologically distinctive uterine leiomyoma with multifocal hemorrhages and hypercellularity which we have designated “apoplectic leiomyoma.” Each occurred in a woman using an oral contraceptive hormonal medication. The hemorrhages and accompanying hypercellularity occasioned some concern as to whether the tumors were sarcoma. In our opinion, such apoplectic leiomyomas have been incompletely characterized and have not been sufficiently delineated from so-called “red degeneration.” This clinicopathologic study of five examples of apoplectic leiomyoma is presented to alert clinicians and pathologists to this lesion.