Pilomatrixoma proliferante una rara variante histopatológica simulando un carcinoma de células escamosas.

Resumen: El Pilomatrixoma es un tumor anexial benigno. Presenta una variante histopatologica infrecuente denominada pilomatrixoma proliferante reportada en 1997 por Kaddu et al. Corresponde a una lesion compuesta predominantemente por una proliferacion lobular de celulas basaloides, con atipia nuclear variable y figuras mitoticas, areas focales que contienen material cornificado eosinofilo, junto con celulas sombra. Se propuso al pilomatrixoma proliferante como un subconjunto histopatologico distintivo del pilomatrixoma y se considero como una variante proliferativa con un perfil histopatologico benigno. La dermatoscopia en este tumor, sobre todo en pacientes de edad avanzada, puede llegar a constituir una trampa dermatoscopica, que es dificil de diferenciar de otras lesiones, como el melanoma o el carcinoma de celulas basales. Existen multiples reportes de casos en la literatura donde se informa de pilomatrixomas clasicos o proliferantes simulando otras neoplasias. Presentamos el caso de una paciente de 88 anos con pilomatrixoma proliferante facial que simulo clinicamente un carcinoma de celulas escamosas y llevo a confusion diagnostica inicial, se destacan las caracteristicas histopatologicas y clinicas de los pilomatrixomas proliferantes. Abstract: Pilomatrixoma is a benign adnexal tumor. It has an infrequent histopathological variant called proliferating pilomatrixoma reported in 1997 by Kaddu et al. It corresponds to a lesion composed predominantly by a lobar proliferation of basaloid cells, with variable nuclear atypia and mitotic figures, focal areas containing eosinophilic cornified material, together with shadow cells. The proliferating pilomatrixoma was proposed as a distinctive histopathological subset of the pilomatrixoma and was considered as a proliferative variant with a benign histopathological profile. Dermatoscopy in this tumor, especially in elderly patients, can result in a dermatoscopic trap, which makes it difficult to differentiate from other lesions, such as melanoma or basal cell carcinoma. There are multiple reports of cases in the literature where classic or proliferating pilomatrixomas were reported simulating other neoplasms. We present the case of an 88-year-old patient with a proliferating facial pilomatrixoma that clinically simulated a squamous cell carcinoma and led to an initial diagnostic confusion, highlighting the histopathological and clinical characteristics of the proliferating pilomatrixoma.