Aggressive angiomyxoma: The first case report in skull

Nine case of a distinctive soft tissue tumor of the female pelvis and perineum are described. They were characterized by their occurrence in young women (ages 21-38), large size (up to 60 X 20 cm), locally infiltrative nature, and grossly gelatinous appearance. The initial clinical impression was usually that of a Bartholin gland cyst. The microscopic appearance was that of spindle or stellate cells widely separated by a loose myxoid stroma focally rich in collagen fibrils, a prominent vascular component, including many large thick-walled vessels without an arborizing pattern, and foci of proliferating glandular elements in two cases. Mitotic activity was exceedingly low. Ultrastructural study of the spindle cells showed features consistent with myofibroblastic differentiation. Four patients developed large local recurrences; one tumor recurred twice, 14 and 15 years after initial excision. No distant metastases have been documented to date, and all patients are alive and well. The differential diagnosis of this unusual tumor includes myxoma, myxoid liposarcoma, sarcoma botryoides, myxoid variant of malignant fibrous histiocytoma, nerve sheath myxoma, and other soft tissue tumors with secondary myxoid changes. We have chosen the term "aggressive angiomyxoma" for this neoplasm to emphasize the neoplastic nature of the blood vessels and its locally infiltrative and recurrent nature.

Aggressive angiomyxoma is a rare tumor that predominates in the female genital tract. Multiple relapses may occur in adjacent organs and tissues, but metastases have not been reported. We present a case of aggressive angiomyxoma in a young woman with multiple local recurrences that metastasized to the lungs, killing the patient. We document this case and report a similar one, found in the literature, of a postmenopausal woman with pulmonary and mediastinic metastases. These cases may expand the current concepts of potential behavior of aggressive angiomyxoma.

Cytogenetically visible aberrations of chromosomal region 12q14-15 in a variety of frequent benign human tumors reflect rearrangements of the HMGI-C gene. The mechanisms by which the HMGI-C gene contributes to tumorigenesis are mostly unknown, although frequently aberrant transcripts containing exons 1 to 3 of HMGI-C and ectopic sequences from other genes due to breaks within the third intron of HMGI-C are detectable. This is the first report analyzing human tissue samples mainly of mesenchymal origin by a highly sensitive polymerase-chain-reaction-based approach detecting HMGI-C expression. We found HMGI-C expression in embryonic tissue but no expression in any of several adult tissues tested except for two myometrial tissues. These data suggest that HMGI-C is mainly expressed in human tissues during embryonal and fetal development. Thus, its particular role for tumor development may be due to the expression of at least exons 1 to 3 rather than to the formation of fusion transcripts.