Resumen

ROJAS-FERNANDEZ, MV; UMERES-FRANCIA, GE; UMERES-ALVARO, JF  y  BENITES-ZAPATA, VA. PRIMARY AMELANOTIC ANO-RECTAL MELANOMA. A CASE REPORT. Rev. argent. dermatol. [online]. 2018, vol.99, n.4, pp.1-7. ISSN 1851-300X.

We present the case of a 37-year-old woman, who came to the clinic for a sensation of anal bulge and hematochezia of 3 months of evolution, with a history of chronic constipation. No pruritus, anal pain or weight loss. On inspection, she presented a 3 cm tumor in the upper left quadrant of the anal region, pink and denuded in appearance. The adjoining mucosa was hyperpigmented. Histopathology reports a round cell tumor, suggestive of melanoma. Immunohistochemistry finally confirms the diagnosis, since it reports positivity to S100, HMB45 and vimentin markers. When performing the disease extension study, implants of the neoplasm are found at the pulmonary and inguinal level, which demonstrates the aggressiveness and poor prognosis of this pathology.

Palabras clave : anorectal melanoma; metastasis; mucosal melanoma; rectum; anus.