Abstract
A 2-year-old male with no significant medical history presented with an 8-month history of a growing, painful occipital mass. Physical examination was remarkable for a multilobulated subcutaneous mass on the occipital scalp. Surgical excision was performed and multiple masses in the periosteal subgaleal space were present. Histopathologic examination showed fragments of subcutaneous tissue with no overlying epidermis consisting of dense aggregates of histiocytes forming palisaded granulomas with central foci of necrobiosis. Immunohistochemical stains performed with CD68 and SMA highlighted the histiocytic infiltrate. Given the clinical history and histopathological findings, the final diagnosis was consistent with subcutaneous granuloma annulare (SGA). SGA, also known as pseudorheumatoid nodule, is an uncommon clinicopathological subtype of granuloma annulare, which is a benign, self-limited inflammatory disorder. It affects children two to five years of age and the prevalence is difficult to access due to its rarity. One of the most relevant differential diagnoses includes epithelioid sarcoma, a soft tissue malignant neoplasm. We submit this case to highlight the importance of proper clinicopathological recognition of this uncommon condition. It is paramount to properly evaluate lesions of this nature due to the similarity of clinical and histopathological features to epithelioid sarcoma. Accurate identification will prevent unnecessary aggressive intervention and mitigate the risks of the associated procedures.
Financial Disclosure:
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