Solid variant of papillary thyroid carcinoma - Incidence, clinical-pathologic characteristics, molecular analysis, and biologic behavior

Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45267-0529, USA.
American Journal of Surgical Pathology (Impact Factor: 4.59). 12/2001; 25(12):1478-84. DOI: 10.1097/00000478-200112000-00002
Source: PubMed

ABSTRACT Solid variant is a rare and poorly characterized variant of papillary thyroid carcinoma. In this study we analyzed 20 primary cases of the solid variant of papillary carcinoma found in a series of 756 papillary carcinomas operated at the Mayo Clinic between 1962 and 1989. The criteria for classification included predominantly (>70%) solid growth pattern of primary tumor, retention of cytologic features typical of papillary carcinoma, and absence of tumor necrosis. For each case of the solid variant, a control case of classical papillary carcinoma matched by age, sex, tumor size, and length of follow-up was selected. The follow-up ranged from 6 to 32 years. Two patients with the solid variant of papillary carcinoma (10%) died from disease 7 and 10 years after initial surgery, while another two patients (10%) are alive with lung metastases. In contrast, the control group had no cases with distant metastases or death from disease. Molecular analyses showed a similar prevalence of RET /PTC rearrangements in both groups. In conclusion, the solid variant of papillary carcinoma is associated with a slightly higher frequency of distant metastases and less favorable prognosis than classical papillary carcinoma. However, it should be distinguished from poorly differentiated thyroid carcinoma, which has a reported lower survival rate compared with the solid variant of papillary carcinoma.

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    ABSTRACT: Some of the numerous examples that can be quoted are those on dysplasia in Barrett's esophagus, 6 grading of prostatic carcinoma, 7 grading of breast carcinoma, 8 diagnosis of hydatidiform mole, 9 and classification of thymic tumors. 10 On first sight, these results make surgical pathology look like a subjective, arbitrary, unscientific discipline, and therefore many surgical pathologists don't like them. I still get occasional snotty remarks about a study of the kind I did many years ago on proliferative ductal lesions of the breast. 11 Yet, I doubt whether burying our head in the sand is the solution. Perhaps it is the nature of the beast, and nothing can be done about it. 12 As Vickery 13 stated, some of the criteria on which we base those distinctions "may be indefinite and vulnerable to subjective morphologic interpretation." Or perhaps some of these studies will identify a specific problem that can be addressed. The various thyroid studies above quoted mainly deal with the diagnostic significance of certain morphologic nuclear features (herein referred to as PTC-type nuclei) in the diagnosis of papillary thyroid carcinoma (PTC). It is obvious from the results obtained that some experts have a much lower threshold for the identification and/or diagnostic significance of PTC-type nuclei than others. It may be of some interest to briefly recount the evolution that PTC-type nuclei have had in thyroid pathology until reaching their presently exalted status. Originally, and for the many decades that followed its description, PTC was diagnosed primarily on the basis of the presence of papillae, hence its name. Then people began noticing that these tumors had peculiar nuclei, which looked empty or optically clear. Ronald DeLellis 14 gave credit to Nancy Warner for drawing the amusing analogy between these nuclei and the eyes of Harold Gray's comic strip character, "Little Orphan Annie". Thus, the expression "Orphan Annie's eyes nuclei" became popular when referring to PTC, although the presence of papillae and other cytoarchitectural features (carefully listed and discussed in Vickery's authoritative review on the subject 13 ) were still regarded as important criteria for the diagnosis of PTC. However, with the passing of the years, PTC-type nuclei rose through the ranks, so to speak, to become the paramount criterion for the diagnosis of PTC. At present, a thyroid tumor can have a papillary, follicular, solid, trabecular or cribriform pattern of growth; it can be composed of large, small, oncocytic, clear, round, spindle or columnar cells; it can be encapsulated, minimally invasive or widely invasive; in sum, it can have any of those features and more, but as long as it has PTC-type nuclei it is thought to be a PTC or one of its innumerable variants.
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    ABSTRACT: Ret rearrangements are common in papillary thyroid carcinoma (PTC), with ret/PTC-3 commonly seen in children exposed to ionizing radiation. In this context ret/PTC-3 has been correlated with solid variant morphology, poorer prognosis, and aggressive tumor behavior. We aimed to assess the prevalence of the common ret chimeric transcripts (ret/PTC-1 and ret/PTC-3) in a group of sporadic PTC and correlate them with tumor morphology. Thyroid follicular cells were laser capture microdissected from sections of archival PTC (n = 28). Total RNA was extracted and analyzed for expression of glyceraldehyde 3-phosphate dehydrogenase, ret/PTC-1, and ret/PTC-3 using TaqMan PCR. Ret/PTC rearrangements were detected in 60% of PTCs. Specifically transcripts of ret/PTC-1 and ret/PTC-3 were detected in 43% and 18% of PTCs, respectively. Ret/PTC-3 was detected in only follicular variant subtype (60%) and was not detected in classic PTC. One case of tall cell variant demonstrated chimeric expression of both ret/PTC-1 and ret/PTC-3 transcripts within the same tumor. This study demonstrated a high prevalence of the two common ret rearrangements in an Irish cohort of PTCs. A correlation of tumor morphology with these common ret rearrangements is suggested.
    Journal of Clinical Endocrinology &amp Metabolism 03/2003; 88(2):938-41. DOI:10.1210/jc.2002-021239 · 6.31 Impact Factor
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