Nevoid melanoma of the vagina: report of one case diagnosed on thin layer cytological preparations

Abstract

Background: Primary melanoma of the vagina is an extremely rare neoplasm with approximately 250 reported cases in the world literature 1234. In its amelanotic variant this lesion may raise several differential diagnostic problems in cytological specimens 5. In this setting, the usage of thin layer cytopathological techniques (Liquid Based Preparations = LBP) may enhance the diagnostic sensitivity by permitting immunocytochemical study without having to repeat the sampling procedure. The aim of this paper is to describe the cytomorphological presentation of primary vaginal melanoma on LBP since it has not previously been reported up to now, to our knowledge.

Case presentation: a 79-y-o female complaining of vulvar itching and yellowish vaginal discharge underwent a complete gynaecological evaluation during which a LBP cytological sample was taken from a suspicious whitish mass protruding into the vaginal lumen. A cytopathological diagnosis of amelanotic melanoma was rendered. The mass was radically excised and the patient was treated with alpha-Interferon.

Conclusion: amelanotic melanoma may be successfully diagnosed on LBP cytological preparations. Thin layer preparations may enhance the diagnostic cytomorphological clues to its diagnosis and may permit an adequate immunocytochemical characterization of the neoplasm.

Figure 1

Thin layer preparation, vaginal melanoma. Note the dispersed proliferation of highly atypical medium sized cells with ovoid or kidney-shaped, nucleolated nuclei. The neoplastic cells display a scarce to moderate amount of greyish granular cytoplasm with peripheral condensation and cytoplasmic projections suggestive of hyperplastic microvilli (Papanicolaou stain, 600×, original magnification).

Figure 2

Thin layer preparation, vaginal melanoma: immunocytochemical stain for HMB 45 showing diffuse cytoplasmic positivity in neoplastic cells.

Figure 3

Thin layer preparation, vaginal melanoma: immunocytochemical stain for S-100 protein showing diffuse cytoplasmic positivity in neoplastic cells. Figs. 2 and 3: immunoperoxidase, 400×, original magnification.

Figure 4

Vaginal melanoma, cross-section of surgical sample. A 5 × 4 × 4 cm whitish solid mass can be observed lined by partly ulcerated vaginal mucosa. The left cervical fornix is visible in the upper center of the picture.

Figure 5

Vaginal melanoma: histopathological section showing an infiltrating dispersed cell population with alveolar pattern of growth (Hematoxylin and Eosin, 250×, original magnification).

Figure 6

Immunocytochemical staining for MART-1 demonstrating diffuse cytoplasmic positivity of the neoplastic cells (Immunoperoxidase, 250×).