PENS hamartoma or “papular epidermal nevus with "skyline" basal cell layer” is a congenital epidermal hamartoma, which is characterized by specific histopathological features. We report a diagnosis of PENS hamartoma that was made in an 18-month-old girl.
Initially described by Torrelo et al. in 2011 (1), PENS hamartoma exhibits particular clinical features consisting of coalescent, verrucous, and light brown polygonal papules (2). The diagnosis is confirmed by histological examination, which, in the majority of cases, shows an alignment of epidermal basal cells and palissadic disposition of nuclei evoking a "skyline". In 2012, the term PENS Syndrome was retained, owing to new clinical descriptions associating light neurological abnormalities with these cutaneous lesions (2). PENS syndrome is a rare neuro-cutaneous syndrome, which involves one or more congenital epidermal hamartomas of PENS type, as well as non-specific neurological abnormalities (1-3). Neurological manifestations begin to occur during the first two years of life (1). A review of the literature identified 27 reported cases of PENS hamartomas (1-12), including some familial cases and other cases associated with neurological abnormalities (PENS syndrome). The physiopathology of PENS hamartoma and PENS syndrome remains unclear, whereas several hypotheses have been advanced (7).
What do we know about the topic?
- PENS hamartoma is a congenital skin lesion that consists of coalescent, verrucous, and light brown polygonal papules.
- The histology is pathognomonic.
- Neurological abnormalities may be associated with these skin lesions as part of PENS syndrome.
What does this article bring up for us?
- This illustrated article describes the clinical aspects of PENS hamartoma in an effort to help clinicians diagnose this pathology.
- It is crucial to recognize these skin lesions is important and search for potential associated neurological abnormalities.
Key Words
PENS, epidermal nevus, skyline