A young man with a mass on the neck.

A 25 year old man was referred to the oncology unit with a three week history of a neck lump that was progressively increasing in size, and atypical lymphoid cells on fine needle aspiration cytology. The patient also reported mild exertional dyspnoea and drenching night sweats, but no weight loss, occupational exposure to harmful substances, recent travel, or high risk sexual behaviour. He had smoked cigarettes since he was 16.On examination, the right supraclavicular lymph node was palpable and measured 3 cm in diameter. Chest radiography showed a widened mediastinum but no lung lesions. Contrast enhanced computed tomography of the thorax was performed (fig 1). Core biopsy of the node showed partial effacement of nodal architecture by scattered large cells in a background of reactive lymphocytes, eosinophils, and plasma cells with some collagen fibrosis. These large cells stained positive for CD15 and CD30 and negative for CD45. Figure 2 shows an example micrograph from biopsy (not from the patient described).Fig 1 Axial contrast enhanced computed tomography of the thorax showing an anterior mediastinal mass, with a central hypodense area suggestive of necrosis (red arrow)Fig 2 Micrograph showing a Reed-Sternberg cell and normal lymphocytes. Reed-Sternberg cells are often binucleated with prominent nucleoli, having an …