Intriguing Subcutaneous Nodules – A Panic-Stricken Panniculitis

A 13-year-old boy presented with multiple transient painless swellings over the body for the past 6 months. Lesions would persist for 6–8 weeks and spontaneously resolve leaving behind discolouration and altered skin texture. Clinical examination revealed a single soft, non-tender mobile nodule of 2 × 2 cm over left arm, along with multiple discrete well defined post-inflammatory hypopigmented patches with hyperpigmented scaly papules over the arms, thighs and trunk. Skin biopsy showed lobular panniculitis composed of lymphoid cells, histiocytes and plasma cells with characteristic rimming of fat cells by lymphoid cells suggestive of cytophagic histiocytic panniculitis. Immunohistochemistry showed positive CD3, CD5, CD7 and CD8, negative CD20, CD4, CD56, Ki67 – 75–80%, CD68 highlighting the histiocytes and C30 negative. Positron emission tomography–magnetic resonance imaging showed multiple fluorodeoxyglucose (FDG) avid cutaneous and subcutaneous nodules throughout the body and minimally FDG avid axillary and inguinal lymph nodes. Thereby, a final diagnosis of subcutaneous panniculitis like T-cell lymphoma was concluded. Our patient was started on tapering dose of oral prednisolone and cyclosporine, following which the lesions significantly improved.