Hyalinizing trabecular tumor

Hyalinizing trabecular tumors are typically positive for TGB and may occasionally exhibit positivity for some NE markers including chromogranin A and hormonal peptides (neurotensin, endorphins). These tumors have plasma membrane patterns of staining with the monoclonal antibody MIB-1 however, this pattern of reactivity occurs only when staining is performed at room temperature rather than at 37° C (Fig. 10.6). The most likely explanation for the plasma membrane pattern of reactivity is that the antibody cross-reacts with an epitope present in the plasma membrane under these conditions. ... 

FIGURE 10.6 A, Hyalinizing trabecular tumor of thyroid (FH E stain). B, Immunoperoxidase stain for MIB-1 performed at room temperature. There is prominent staining of the plasma membranes of tumor cells. 

There is considerable controversy with respect to the presence of CK19 in hyalinizing trabecular tumors of the thyroid. Fonseca and coworkers reported CK19 in all cases of hyalinizing trabecular tumors and suggested that this tumor represented a peculiar encapsulated variant of papillary carcinoma. Hirokawa and colleagues, in contrast, found no or minimal CK19 in their series of cases. 

The ret oncogene protein has been demonstrated by immunohistochemistry both in papillary carcinomas and in a subset of hyalinizing trabecular tumors." " However, additional studies are required to ascertain the sensitivity and specificity of currently available ret antibodies in immunohistochemical formats for the identification of papillary carcinomas. 

Cheung CC, Boerner SL, MacMillan CM, et al. Hyalinizing trabecular tumor of the thyroid A variant of papillary carcinoma proved by molectrlar genetics. Am J Surg Pathol. 2000 24 1622-1626. 

Mixed medullary and follicular cell carcinoma Spindle cell tumor with thymus-like differentiation Carcinoma showing thymus-like differentiation Thyroid adenoma and related tumors Follicular adenoma Hyalinizing trabecular tumor... 

Bocker W, Dralle H, Dorn G. Thyroglobulin An immunohistochemical marker in thyroid disease. In DeLellis RA, ed. Diagnostic Immunohistochemistry. New York Masson 1981 37-60. Sambade C, Franssila K, Cameselle-Teijeiro J, et al. Hyalinizing trabecular adenoma A misnomer for a peculiar tumor of the thyroid gland. Endocr Pathol. 1991 2 83-91. 

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