Vaginal stromal sclerosis: a distinctive stromal change associated with vaginal atrophy.

The author describes 3 cases of an unusual vaginal lesion, designated as "vaginal stromal sclerosis," that is believed to represent a clinically and pathologically distinct disease. The 3 patients, aged 62, 52, and 50 years, all presented with dyspareunia and had clinical evidence of vaginal atrophy. The lesions were either a solitary firm vaginal nodule (2 cases) or multiple firm distal vaginal plaques (1 case), each of which measured less than 1 cm. All were nontender and nonfluctuant. Microscopically, the lesions were characterized by poorly delineated, diffuse zones of stromal paucicellular hyalinization, comprising fine collagen and elastic fibers, which extended upward to the basement membrane layer of the overlying epithelium, and downward to the deepest portions of most of the biopsies. Constituent cells were largely monomorphic, with irregular, pyknotic nuclei and small cytoplasmic extensions. Mitotic figures or tissue necrosis were not identified. There were small, thin-walled, capillary-caliber vessels in the upper layers of the hyalinized zone, whereas the deeper areas displayed larger caliber arteries in addition to small vessels. Occasional plaques of eosinophilic collagen were observed in 2 cases. Epithelial changes included hyperkeratosis in 1 case, and mild-to-moderate atrophy with loss of normal rugae formation in all 3 cases. Histochemical studies for Congo-red (amyloid), Gomori-Methamine-Silver (fungal forms), and phosphotungstic acid hematoxylin (fibrin) were negative. An elastin histochemical study showed a marked increase in elastic fibers within the stromal compartment relative to the adjacent normal vaginal stroma. By immunohistochemistry, the stromal cells were diffusely positive for vimentin, and were negative for CD34, desmin, smooth muscle actin, muscle-specific actin, progesterone receptor, and p53 in all 3 cases. The paucicellular foci of hyalinization were similarly vimentin positive. The stromal cells displayed diffuse immunoreactivity for the estrogen receptor in 2 cases and were negative in the third case. The uniform clinical presentation of dyspareunia and vaginal atrophy, the notably firm consistency of the nodules and plaques, and the distinctive morphologic features, all suggest that this lesion is worthy of segregation. Potential differential diagnostic considerations are discussed. It is postulated that this lesion is an unusual reparative stromal change that may be related to atrophy-related vaginal irritation or injury.