The final diagnosis was a colloid signet-ring cell carcinoma of the colon with lymph node involvement.
The extreme rarity of a primary colorectal signet-ring cell carcinoma metastatic to the tonsil reflects the fact that this particular histologic type of cancer occurs in only about 1% of all cases of colorectal carcinoma.
172) Other malignant tumors should be considered if signet ring cells are present: (1) poorly differentiated adenocarcinoma with focal signet ring cells; (2) squamous cell carcinoma with signet ring-like cells; (3) clear cell carcinoma with signet ring cells; and (4) metastatic signet-ring cell carcinoma (more often gastrointestinal and breast origin).
Primary signet-ring cell carcinoma of the cervix: case report and review of the literature.
3,4] Saphir first described primary signet-ring cell carcinoma
of the bladder in 1955, and less than 200 cases have been reported in the literature since then.
In contrast, typical intracytoplasmic inclusions in signet-ring cell carcinoma
are slightly bluish and have a more-vacuolated appearance with a distinct border with the cytoplasm.
The only histologic types of colorectal carcinoma that have been shown to have adverse prognostic significance independent of stage are signet-ring cell carcinoma
(6) and small cell carcinoma (high-grade neuroendocrine carcinoma).
Primary signet-ring cell carcinoma
of lung: immunohistochemical study and comparison with non-pulmonary signet-ring cell carcinomas
Signet-ring cell carcinoma
([is greater than] 50% signet-ring cells)([sections])
Immunohistochemical characterization of signet-ring cell carcinomas
of the stomach, breast, and colon.
4,5) High-grade tumors, such as signet-ring cell carcinomas
, small cell carcinomas, and undifferentiated carcinomas, are associated with a poorer prognosis compared with adenocarcinoma.