Fine Needle Aspiration of Hematolymphoid Lesions of the Thyroid: Onsite Adequacy and Ancillary Testing

A 7-year-old girl presented with an enlargement of the thyroid gland. yroid hormones and serologic testing were normal. A thyroid ultrasound showed a right 0.8 cm thyroid nodule with microcalcifications and well-defined borders. Fine needle aspiration (FNA) revealed polymorphic lymphocytes without Hurthle cells [Figure 1a-d]. Flow cytometry showed a population of CD2+, CD5+, CD8+, CD7+, CD4+, and CD1a+ cells. Immunohistochemistry on cell block section showed immunoreactivity for TdT without immunoreactivity for CD34.