Pseudogranulomatous Spitz nevus: a variant of Spitz nevus with heavy inflammatory infiltrate mimicking a granulomatous dermatitis
Article first published online: 18 SEP 2012
Copyright © 2012 John Wiley & Sons A/S.
Journal of Cutaneous Pathology
Volume 40, Issue 3, pages 330–335, March 2013
How to Cite
Pseudogranulomatous Spitz nevus: a variant of Spitz nevus with heavy inflammatory infiltrate mimicking a granulomatous dermatitis., , , , .
- Issue published online: 20 FEB 2013
- Article first published online: 18 SEP 2012
- Manuscript Accepted: 25 FEB 2012
- Manuscript Revised: 17 NOV 2011
- Manuscript Received: 24 MAR 2011
- granulomatous dermatitis;
- pseudogranulomatous Spitz nevus;
- regression of melanocytic nevus
Spitz nevus is a benign melanocytic proliferation that shows relatively characteristic clinicopathologic features. Despite this, Spitz nevus is clinically confused with many other lesions, and histopathologically it is sometimes difficult to distinguish it from melanoma. However, Spitz nevus rarely causes differential diagnostic problems with granulomatous dermatitis. This article describes an 8-year-old girl who presented with a nodule on her right arm, a clinical appearance of a pyogenic granuloma. Histopathologically, there was a dermal lesion composed of aggregates of large epithelioid cells surrounded by a heavy inflammatory infiltrate, mimicking a sarcoid-like granulomatous dermatitis. Immunohistochemistry showed epithelioid cells with strong nuclear and cytoplasmic staining with S-100 protein, thus establishing the diagnosis of a melanocytic tumor. The heavy T-cell lymphocytic infiltrate that accompanies the large epithelioid cells caused its granulomatous appearance. Molecular assessment showed H27H mutation in the HRAS gene. We suggest the term ‘pseudogranulomatous’ for this variant of Spitz nevus because it indicates that the lesion is not authentically granulomatous and simply mimics a granulomatous dermatitis.