Wegener's granulomatosis presenting as a thyroid mass.

A 71-year-old patient was referred for suspected hyperthyroidism because of a 15-kg weight loss, suppressed thyroid stimulating hormone (TSH), and a 4-cm nodule in the left thyroid lobe. Both free T4 and T3 were normal. Antithyroglobulin, anti-TSH receptor and antimicrosomal antibodies were absent. Thyroid scintigraphy showed a cold nodule in the left thyroid lobe. CAT scan of the neck revealed a 4-cm inhomogeneous nodule at the left side. An elevated sedimentation rate suggested bacterial thyroiditis, localized Quervain thyroiditis, malignancy, and the fibrosing variant of Hashimoto's thyroiditis or Riedel's thyroiditis. A fine needle biopsy of the thyroid nodule showed no malignant cells but was inconclusive. A true cut biopsy demonstrated atypical inflammation and also failed to reveal the diagnosis. Therefore, the patient was admitted to the hospital for further work-up and was unexpectedly found to have nodular lesions in the lung on a chest X-ray. Additional blood analysis revealed a positive cytoplasmic ANCA-titer. After inconclusive peripheral lung biopsies, a left hemithyroidectomy and a very large video-assisted thoracoscopic lung biopsy were performed, both revealing extensive zones of necrosis surrounded by granulomatous foci pointing to the diagnosis of Wegener's granulomatosis (WG) disease. To our knowledge, this is the first report of a well-documented WG of the thyroid gland. Although extremely rare, WG should be included in differential diagnosis of inflammatory lesions of the thyroid gland.