Cytologic and histological features of rare nonepithelial and nonlymphoid tumors of the thyroid

Abstract

Thyroid tumors can be classified into epithelial, nonepithelial, and nonprimary lesions. Nonepithelial thyroid tumors are rare. They can be of primary origin within the thyroid gland, arise secondary to contiguous growth from adjacent tissues, or represent metastatic disease. The incidence of nonepithelial tumors of the thyroid is only 1% to 2%, most of which are lymphomas; the remainder includes mesenchymal and histiocytic tumors. This review examines the cytohistological features of various nonepithelial and nonlymphoid tumors of the thyroid, including vascular lesions, neural tumors (including granular cell tumor and paraganglioma), smooth muscle tumors, solitary fibrous tumor, histiocytic neoplasms (eg, Langerhans cell histiocytosis and Rosai‐Dorfman disease), and follicular dendritic cell sarcoma. Their differential diagnosis is discussed, including recommendations to prevent the pitfall of mistaking these rare tumors for more common epithelial thyroid neoplasms.

Histopathological Characteristics and Incidence of Thyroid Carcinoma in a Tertiary Care Hospital of Pakistan - A retrospective study

“…Thyroid carcinoma is the most frequently occurring cancer of endocrine organs 9 . Non-epithelial tumors and lymphomas of the thyroid are extremely rare 10,11 . High incidence of thyroid tumors has been perceived in different areas of the world.…”