Introduction: Hibernomas are rare benign soft tissue tumours arising from brown adipose tissue, typically occurring in areas where brown fat persists, most commonly the thigh. They represent less than 2% of benign lipomatous tumours and are characterised by a rich vascular supply and distinctive brown fat histology. Although benign, hibernomas can mimic malignant soft tissue neoplasms such as liposarcoma on imaging due to their heterogeneous appearance and FDG uptake. Cervical hibernomas are uncommon, making clinical recognition important to prevent unnecessary aggressive management. Background: A 24-year-old male presented with a painless left neck mass, first noticed two months prior. He reported sharp pain during biopsy and transient paraesthesia on palpation. His medical history included hayfever and previous lipomas. He was a social smoker, binge drank on weekends and was independent in daily activities. Examination and Imaging: Clinical examination revealed a soft, mobile, 5 cm lesion in the left supraclavicular fossa with intact cranial nerve and limb function. Ultrasound-guided core biopsy was non-diagnostic. MRI demonstrated a 40 × 49 × 48 mm T2-hyperintense lesion with heterogeneous enhancement, not continuous with the brachial plexus, and no cervical lymphadenopathy. Differential diagnoses included nerve sheath tumour or soft tissue sarcoma. Histology: Excisional biopsy revealed lobules of brown adipocytes admixed with white adipocytes, rich vascularity, and absence of atypia or necrosis. These features are diagnostic of a benign hibernoma. Fourteen lymph nodes were benign. Conclusion: Hibernoma is a rare benign tumour that can mimic more aggressive soft tissue neoplasms on imaging. Awareness of this entity is essential to avoid overtreatment and guide appropriate management. 1.Furlong MA, Fanburg–Smith JC, Miettinen M. The Morphologic Spectrum of Hibernoma: A Clinicopathologic Study of 170 Cases. The American Journal of Surgical Pathology. 2001;25(6):809-14