The differential diagnosis of thyroid gland enlargement with systemic symptoms includes lymphoma, tuberculosis, fungal infection, sarcoidosis, palpation thyroiditis, and de Quervain thyroiditis. Granulomatous thyroid gland enlargement with systemic symptoms is typical of de Quervain thyroiditis; however, it usually produces a painful goiter, with derangements in thyroid function test results. Negative acid-fast bacilli and India ink stains essentially rule out mycobacterial and fungal infections. Palpation thyroiditis is defined as glandular inflammation that is induced by mechanical trauma and can be disregarded as a diagnosis if there is no history of neck surgery, glandular trauma, or recent serial thyroid examinations. In this case, mediastinal lymphoma with thyroid involvement was also suspected; however, thyroid and transbronchial lymph node biopsy specimens failed to show malignant cells. Histopathologic examination of the biopsy specimens revealed nonnecrotizing granulomas, suggesting a diagnosis of sarcoidosis with thyroid gland involvement. Serum angiotensin-converting enzyme levels as high as 103 U/L (reference range, 9-67 U/L) provided additional evidence to support this diagnosis.
Pathology Quiz Case 1: Diagnosis. Arch Otolaryngol Head Neck Surg. 2007;133(7):730. doi:10.1001/archotol.133.7.730-a