Abstract

Darier-Roussy sarcoidosis (subcutaneous sarcoidosis) is a rare variant of sarcoidosis that clinically presents as firm, deep nodules on the trunk or extremities in 1-12% of patients with sarcoidosis. We present a case of a 46-year-old female who underwent screening breast mammography showing mixed echogenic masses in both breasts, categorized as BI-RADS 4 (“suspicious”).  Subsequently, she noted numerous painful subcutaneous nodules over her trunk and extremities.  She had recent extensive cross-country travel and endorsed a 15-pound weight loss and intermittent night sweats, which she attributed to complicated COVID-19 and urinary tract infections. Ultrasound-guided core-needle biopsy of the breast nodule showed numerous well-formed, non-caseating granulomas with a variable background infiltrate of lymphocytes and plasma cells. Histochemical stains were negative for fungus and acid-fast bacilli. Subsequent punch biopsy of one of the back nodules showed similar findings of dense subcutaneous granulomatous and lymphoplasmacytic inflammation. Histochemical stains and microbiologic cultures excluded an infectious etiology.  Additional immunohistochemical stains were not supportive of a lymphoproliferative disorder with secondary granulomatous inflammation. With the exclusion of other causes of granulomatous inflammation, and clinicopathologic correlation, a diagnosis of Darier-Roussy sarcoidosis was rendered.  Computerized tomography of the chest revealed no enlarged mediastinal or hilar lymph nodes.  The patient was started on a three-week prednisone taper and showed marked improvement with near-complete resolution of the cutaneous lesions. This case highlights a unique presentation of subcutaneous sarcoidosis diagnosed on breast needle-core biopsy, following screening mammography, and emphasizes the variable clinical manifestations of sarcoidosis.