A diagnostic dilemma: a young boy with loss of weight, pulmonary infiltrates and cervical lymphadenitis.

Cervical lymphadenitis is a common finding in young adults in a country like India, where tuberculosis is endemic. We are presenting the case of a young boy who presented with low grade fever, dry cough, weight loss, and a cervical swelling. His chest X-ray showed diffuse reticulonodular infiltrates. Contrast enhanced CT of chest showed bilateral multiple ring shadows. Cervical lymph node fine needle cytology suggested a metastatic thyroid carcinoma. He was evaluated extensively and a final diagnosis of a familial medullary thyroid carcinoma was made. Medullary thyroid carcinoma should be considered in the differential diagnosis of cervical lymphadenitis with lung infiltrates in young adults. It may be sporadic or a part of an inherited autosomal dominant disorder like multiple endocrine neoplasia. Genetic testing should be done for all patients with a diagnosis of medullary thyroid carcinoma.