RESUMO
Porokeratosis (PK) is an epidermal disorder of keratinization, caused by a clone expansion of a mutated keratinocyte that generates a thin parakeratotic column: the cornoid lamella (CL). Depending on the clinical presentation, we differentiate up to 6 different types of PK. Most frequent locations for the lesions are limbs and trunk, while scalp is rarely affected. The possible origin of the CL in the epidermal appendages has been proposed (ostia of the eccrine glands and infundibulum of the follicle). The first case of PK limited to the scalp with exclusive involvement of the hair follicles is presented in this manuscript. It helps identify the clinical description and especially the trichoscopy as a diagnostic key in follicular PK and also to elucidate if it is an incidental histological finding or a new different clinical variant of PK.
RESUMO
Eccrine mucinous nevus is an uncommon hamartoma whose histological diagnosis is simple because of its peculiar morphological features, which include an increase in the number and/or size of the glands and eccrine ducts accompanied by abundant mucin deposits. When it presents with the typical symptom, focal hyperhidrosis, clinical suspicion is possible. El nevus mucinoso ecrino (NME) es un hamartoma escasamente reportado en la literatura cuyo diagnóstico histológico es sencillo debido a sus peculiares rasgos morfológicos, que incluye un aumento del número y/o tamaño de las glándulas ductos ecrinos acompañado de abundante depósito de mucina. Cuando presenta los hallazgos típicos, como la hiperhidrosis focal, es posible su sospecha clínica.