Squamous syringometaplasia in association with annular elastolytic granuloma.

Squamous syringometaplasia, squamous metaplasia of eccrine glands, is considered to be an important component of pseudoepitheliomatous hyperplasia, which can be a response to a variety of conditions. Recently, squamous syringometaplasia was described as occurring in lobular panniculitis, pancreatic panniculitis, and pyoderma gangrenosum. We report a case of annular elastolytic granuloma with associated squamous syringometaplasia. The initial biopsies were superficial, and the squamous syringometaplasia extended to the base of the specimen, closely resembling squamous cell carcinoma. Immunohistochemical stains for carcinoembryonic antigen outlined eccrine structures. The special stains and an excisional biopsy helped confirm the diagnosis. In addition, the clinical course has been consistent with the diagnosis of annular elastolytic granuloma. It is postulated that the dense granulomatous inflammatory infiltrate in annular elastolytic granuloma damages the eccrine structures, and this damage initiates the process.