Kinase fusion-related thyroid carcinoma, classic papillary thyroid carcinoma with follicular-patterned component, multinodular, well-circumscribed and focally encapsulated with intratumoral fibrosis and with invasion into adjacent parenchyma, 5.8 cm, right thyroid lobe. See note.
Lymphovascular invasion is identified and with intrathyroidal spread with satellite tumor nodules present.
The tumor infiltrates adjacent thyroid.
Multiple levels are examined.
Immunohistochemistry performed at MGH shows that that the lesional cells have strong membranous immune expression of HBME-1. HBME-1 also highlights the multinodularity and the invasive component present in adjacent thyroid. Immunohistochemistry for p53 shows a wild-type pattern. Cyclin D1 is multifocally positive, wild-type pattern. Immunohistochemistry for CD31 highlights lymphatic invasion. D2-40 immunostain confirms the lymphatic invasion. Ki-67 proliferative index is focally up to 4%.
Immunohistochemistry for pan-TRK is positive in tumor cells, suggestive of an NTRK fusion. Subsequent molecular evaluation is recommended.
Immunohistochemistry for ALK TR shows a lack of cytoplasmic ALK expression. The finding is unlikely to be associated with an ALK fusion gene product.
Immunohistochemistry performed at the outside institution and reviewed at MGH to assess for BRAF p.V600E is negative.
Lymphocytic thyroiditis.
Thyroid with multifocal granulomatous inflammation.
Metastatic kinase fusion-related thyroid carcinoma to 1 out of 1 perithyroidal lymph node (1/1). The tumor focus measures 0.4 cm. No extranodal extension is seen.
Lymph node with focal giant cells with noncaseating granulomatous inflammation.
One intrathyroidal cellular parathyroid gland (block A13).
