COLLOID (mucoid) carcinoma is an adenocarcinoma, a columnar-cell carcinoma in which the cells are arranged in the form of glands.
According to the nature of the glandular formations, these tumors are often classified into an alveolar (Fig 1) and a pseudopapillary type, but between the two there are transitional varieties.
Colloid carcinomas occur mainly among the alveolar types. An adenocarcinoma is designated as a colloid carcinoma if there is a violent production of mucoid substance filling and transforming the columnar cells to such an extent that they form typical signet-ring cells with nuclei which are flattened and of a peripheral situation. The mucoid substance may also transform the alveoli into large cysts, in some cases completely splitting up the alveolar structure.
Colloid carcinomas may be grouped into (1) primary colloid carcinoma arising from mucussecreting cells and (2) secondary colloid carcinoma arising from mucoid degeneration of an existing adenocarcinoma. This
J. WORSOE-PETERSEN. Colloid Carcinoma of the Nasal Cavity and Sinuses. Arch Otolaryngol. 1965;82(2):181–185. doi:10.1001/archotol.1965.00760010183018