SECTION EDITOR: MARY S. STONE, MD; ASSISTANT SECTION EDITORS: SOON BAHRAMI, MD; CARRIE ANN R. CUSACK, MD; MOLLY A. HINSHAW, MD; ARNI K. KRISTJANSSON, MD; LORI D. PROK, MD
Histopathologic examination revealed pronounced epidermal papillary architecture and prominent dermal fibrosis with dense, sclerotic collagen bundles (Figure 2). Large epithelioid cells with granular cytoplasm and pustulo-ovoid bodies of Milian (arrows) were found between collagen bundles and tracking into deep subcutaneous fat along fibrous septae (Figure 3). These cells stained positively with S-100, calretinin, and inhibin, confirming a diagnosis of granular cell tumor.1 No high-risk histologic or clinical features of malignant granular cell tumor were identified (see Discussion section). During standard surgical excision, the base of the tumor was found attached to the medial cutaneous nerve of the forearm or branch thereof. The patient experienced sharp pain when the nerve was physically irritated. Given the discomfort under local anesthesia, the tumor was dissected from the nerve. The patient later underwent reexcision with orthopedic surgery. No evidence of residual granular cell tumor was detected, and there was no clinical recurrence at the 14-month follow-up.
Solitary Cerebriform Nodule—Diagnosis. JAMA Dermatol. 2013;149(5):609-614. doi:10.1001/jamadermatol.2013.3058b