[561] Perianal Verrucous Porokeratosis, a Rare Lesion Mimicking Inflammatory and Neoplastic Conditions

Rebecca M Ziegler, Kamruz Darabi, Joseph S Roy, Colleen S Embi, Sara B Peters. The Ohio State University Medical Center, Columbus, OH

Background: Porokeratosis (PK) represents a heterogenous group of lesions with disordered keratinization with a distinctive ridge-like border. The key histologic feature of PK is the cornoid lamella with a column of parakeratotic cells overlying epidermis with a decreased to absent granular layer and dyskeratotic cells in the stratum spinosum. A verrucous variant of PK involving the gluteal cleft has recently been described.
Design: To assess the frequency of perianal verrucous PK, we retrospectively searched our institutional pathology database from 2001-2011 for perianal skin lesions with one of the following diagnostic/microscopic terms, “porokeratosis”, “hyperkeratosis”, “cornoid lamella”, “columnar parakeratosis”, “atypical squamous proliferation”, “verrucous” and “benign keratosis”. Carcinomas, intraepithelial neoplastic lesions, melanocytic nevi, ulcers/abscesses/fistula tracts, and spongiotic dermatitides were excluded. Eighty-seven cases were available for review. The pre-biopsy clinical impression for each case was also collected.
Results: Of the 87 cases reviewed, four cases were identified as diagnostic of verrucous PK, and no misdiagnoses were found. The patients ranged in age from 50 to 75 (mean: 60; median: 58) and included 2 males and 2 females. The clinical impressions included inflamed seborrheic keratoses, malignant neoplasms, condyloma acuminata and inflammatory skin conditions, such as psoriasis, papular eczema, and lichen simplex chronicus. Histologically the four biopsies showed hyperkeratosis and acanthosis with cornoid lamellae overlying dyskeratotic cells, a decreased to absent granular layer and irregular papillomatosis. The remaining 83 patients ranged in age from 9 to 93 (mean: 44; median:45) and included 47 males and 36 females. The diagnoses included 5 (6%) psoriasis, 25 (30%) viral-associated keratoses and 53 (65%) variants of benign keratoses.
Conclusions: Gluteal verrucous PK is an uncommon variant of PK. In order to avoid a misdiagnosis, dermatologists and dermatopathologists must consider PK in the differential diagnosis of persistent verrucous, psoriasiform or lichenified perianal/gluteal plaques.
Category: Dermatopathology

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 129, Wednesday Afternoon


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