FINAL DIAGNOSIS: AGGRESSIVE ANGIOMYXOMA WITH FOCAL MARKED VASCULAR SMOOTH MUSCLE PROLIFERATION
Aggressive angiomyxoma (AAM) is typically a fibromyxoid tumor of adult women under the age of 50 years. It shows a predilection for pelvic and perineal regions and tendency for local recurrence. Usually, it presents as a slow-growing mass mimicking Bartholin gland cyst, vaginal cyst, hernia or lipoma. Imaging studies demonstate iso- or hypoattenuating mass growing around pelvic floor structures. A small number of cases were also reported in men, with a median age of 52 years.
The neoplasm has a very distinctive morphology; however, recurrent lesions can be more cellular and occasionally pose a differential diagnostic challenge. Differential diagnosis includes angiomyofibroblastoma (<5cm, delicate capilaries, epitheloid perivascular cells, well circumscribed), superficial angiomyxoma (paucicellular with abundant mucopolysaccharide matrix, perivascular inflammation, ER-/PR-), intramuscular myxoma, myxoid liposarcoma, myxoid MFH (prominent arborizing vessels) and myxoid leiomyoma (bundles of smooth muscle cells). Cytogenetic and molecular studies demonstrate frequent rearrangement of chromosome 12 q15 involved in various translocations. The HMGIC gene localized in this region is a DNA architectural organizer protein with expression restricted to fetal tissues; it has been shown to be aberrantly expressed in the aggressive angiomyxoma cells.
As of 11/07, the patient is disease-free. Sequelae of pelvic exenteration include permanent colostomy, urethroperineal fistula with recurrent UTIs and neurogenic bladder requiring frequent self-catheterizations.
Contributed by M. Dvorakova, M.D. and A. Palekar, M.D.