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The clinicopathologic significance of mucus production by adenocarcinoma of the colon and rectum was analyzed in retrospective study with stage matched non‐mucus producing control carcinomas. Mucinous carcinoma of the colon and rectum comprised 132 (15%) of 893 cases of colorectal carcinoma. The rectum was the most common site (33% of cases). While 120 mucinous cancers had a poorer five‐year survival than non‐mucinous tumors (34% vs. 53%, p <.005), these had a particularly bad prognosis in the rectum (18% 5 year survival vs. 49% for the non‐mucinous tumor controls, p <.005). The theoretical basis for this location‐dependent behavior is considered. From this study, distinctive clinico‐pathologic features emerge. There were seven documented cases of ulcerative colitis and 8 additional patients gave a history of “colitis”. An additional five patients had received prior pelvic irradiation. Of particular note was the fact that 31% of mucinous carcinomas were associated with villous adenomas, implying a histogenetic relationship. Moreover, this finding again emphasizes the neoplastic potential of the villous adenoma, especially in the rectum where the development of mucinous carcinoma is particularly ominous.

Inactivation of the RB gene is common in parathyroid carcinoma and is likely to be an important contributor to its molecular pathogenesis. The presence of such inactivation may help to distinguish benign from malignant parathyroid disease and may have useful diagnostic, prognostic, and therapeutic implications.

Current models for tumorigenesis propose that a series of genetic alterations occur during the progression from the normal cell to the malignant phenotype. Mutations in each of the three ras genes (K-ras, H-ras, and N-ras) have been identified in many human neoplasms, including thyroid cancer. In this study we examined genomic DNA from benign and malignant thyroid neoplasms for mutations that are known to activate the ras oncogenes (codons 12, 13, and 61). DNA from frozen surgically excised tissue (n = 8) and from formalin-fixed paraffin-embedded tissue (n = 30) was amplified by the polymerase chain reaction and screened for mutations using oligonucleotide-specific hybridization. No mutations were identified in follicular adenomas (n = 9). In follicular carcinomas, 2 of 14 tumors contained mutations (N-ras 61, Gln to Arg), and both of these patients had bone metastases. One of 15 papillary carcinomas had a ras mutation (H-ras 12, Gly to Ser). In contrast to other studies, we found that ras mutations are relatively uncommon in both benign and malignant thyroid neoplasms. Studies of larger numbers of tumors and comparisons of different patient populations will be required to assess a possible association of mutations in N-ras 61 with clinically aggressive follicular cancer.

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Among 237 patients with grossly noninvasive (intrathyroidal) papillary carcinoma of the thyroid treated by surgery at the Massachusetts General Hospital and followed for a median of 14 years, no patient had tumor recurrence either in the thyroid bed or opposite lobe. There were 12 metastatic recurrences with risks of recurrence 4.0% and 6.9% at 10 years and 20 years respectively. Eight of these recurrences were restricted to cervical lymph nodes and did not herald the development of more serious recurrent disease. The remaining recurrences were lung metastases in four patients, two of whom died, accounting for the only deaths from thyroid carcinoma in this series. Factors that influenced the risk of recurrence included lymph node metastases at initial surgery, large tumor size, and to a lesser extent, male sex. The majority of patients (176) had subtotal thyroidectomies, mostly lobectomy (131 patients). There was no evidence that the 61 patients who underwent total thyroidectomy fared better than those with similar patient and tumor characteristics on whom subtotal procedures were performed. The overall findings of this study strongly support the concept that intrathyroidal thyroid carcinoma can be successfully treated by conservative surgery.