Chest wall and axillary lipomatosis in association with cystic hygroma, thyroid nodules, and vascular complications—a comprehensive case study

Lipomas, benign proliferations of mature adipose tissue, are the most common subcutaneous mesenchymal tumors and typically remain asymptomatic unless they enlarge significantly or involve critical structures. Lipomatosis, the diffuse formation of multiple lipomas, is a rare condition that can affect atypical anatomical sites, posing diagnostic and therapeutic challenges. We present a rare case of a 22-year-old female with diffuse lipomatosis involving the thyroid, axilla, anterior chest, and left breast, presenting with progressive swelling, compressive symptoms, and functional limitations. Imaging and histopathology confirmed benign adipose proliferation without malignancy. Surgical management included total thyroidectomy, level V neck dissection, and excision of 13.57 kg of lipomatous tissue. Postoperatively, the patient developed a left upper limb deep vein thrombosis (DVT), successfully managed with anticoagulation. Follow-up showed no recurrence or residual lipomatosis. This case highlights the unusual presentation of extensive lipomatosis involving the thyroid and emphasizes the need for thorough diagnostic workup and careful surgical planning to optimize patient outcomes.