Porokeratoma Case Study

Background: Porokeratoma is a relatively new entity with a different pattern of cornoid lamella from Porokeartosis. First described by Walsh in 2007 as a solitary lesions, since then there has been only one case report of multiple Porokeratomas on the lower extremities. Herein we report a case of multiple Porokeratomas on the upper extremities.
Case report: A 43-year-old man, presents with a 6 months history of multiple asymptomatic lesion on his left forearm. Ineffectively tried treating the lesion with a cream ??? On physical exam, there were two hyperkeratotic skin colored nodules with adherent scales on the left extensor forearm. Also noted a single annular, pink plaque with raised border on the left arm. The differential diagnosis included were Nummular eczema, Squamous cell carcinoma, Hyperkeratotoic Lichen Planus and Porokeratosis. The largest lesion was removed by excisional biopsy. The specimen exhibited
Discussion: Porokeratoma is a separate form of Porokeratosis, both clinically and histologically. The term Porokeratoma was first described in 2007 by Walsh, as an acanthoma with distinct pattern of cornoid lamellation from Porkeratosis.(5) The findings in our patient where similar to what was described by Walsh, except in our case the lesions were of a shorter duration, multiple and also presented with a single satellite lesion of Porokeratosis. To the best of our knowledge, there have been case reports of multiple lesion after the entity of Porokeratoma was introduced, but none of which were on the upper extremities. ( 1,3,4)
Clinically, Porokeratomas can present as scaly plaques or nodules with central hyperkeratosis, some of which can look verrucous. (5) While, Porokeratosis presents as scaling annular plaques of various sizse with ridge – like hyperkeratotic edges, centeral hypopigmenation, and atrophy.