Ultrasound examination allows diagnosis, biopsy guidance, and follow-up of subcutaneous sarcoidosis. The typical pattern is lobular panniculitis with hypoechoic dermal or subcutaneous tissue nodules or pseudo-nodules with peripheral, internal, or global hypervascularity surrounded by hyperechogenic areas. We present a case of a 56-year-old female patient with firm, mobile, and painless cutaneous swellings on the dorsal aspect of wrists, hands, and elbows, on the anterior surface of legs, and in the gluteal regions. Ultrasonography shows hypoechoic subcutaneous tissue pseudo-nodules surrounded by hyperechogenic areas. Histopathological examination demonstrates noncaseating granulomas with epithelial macrophages and multinucleated giant cells surrounded by lymphocytes in subcutaneous tissue and dermis, typical of subcutaneous sarcoidosis, usually appearing in early or mild form of sarcoidosis. Darier–Roussy syndrome presents with subcutaneous nodules on the upper and lower limbs in patients with multiorgan alterations. Ultrasonography allows the diagnosis of early or mild forms of sarcoidosis, sparing unnecessary lung or mediastinal biopsies.
Pitrone et al. (Mon,) studied this question.