Poorly differentiated (‘insular’) carcinoma of the thyroid
Article first published online: 12 DEC 2008
© 1995 Cambridge Philosophical Society
Volume 45, Issue 9, pages 663–668, September 1995
How to Cite
Mizukami, Y., Nonomura, A., Michigishi, T., Noguchi, M., Ohmura, K., Nakamura, S. and Hoso, M. (1995), Poorly differentiated (‘insular’) carcinoma of the thyroid. Pathology International, 45: 663–668. doi: 10.1111/j.1440-1827.1995.tb03519.x
- Issue published online: 12 DEC 2008
- Article first published online: 12 DEC 2008
- Received 18 October 1994. Accepted for publication 8 May 1995.
- nisular carcinoma;
- thyroid gland
Three cases of unusual poorly differentiated (‘insular’) carcinoma of the thyroid gland are presented. These three thyroid carcinomas were large; the tumors from patients 1 and 3 were encapsulated, and that from patient 2 showed invasive growth. Microscopically the tumors were characterized by welldefined solid nests (insulae), which were composed of rather small and uniform tumor cells with round to oval nuclei. Formation of small and colloid-containing follicles was associated with these nests to varying degrees. The tumors of patients 1 and 3 were composed entirely of insular components, but that of patient 2 was associated with small areas of welldifferentiated follicular carcinoma. The metastatic tumors of patients 1 and 2 were essentially similar to the primary with small foci of follicular carcinoma.
Patient 1 is alive with local and mediastinal node recurrences, but patient 2 died of the disease with local recurrences and metastases to lungs, bones and skin. Patient 3 had no recurrences and died of unrelated disease 5 years after surgery. The present study indicates that insular carcinomas have characteristic histologic features and a less favorable prognosis, confirming the findings of previous studies.