Cells of squamous cell carcinoma in pleural, peritoneal and pericardial fluids. Origin and morphology.

The records of two cytopathology laboratories, covering an aggregate of 33 years, were searched for pleural, peritoneal and pericardial fluids reported as containing cells of squamous cell carcinoma (SCC). This search embraced 9,297 serous fluids from 7,389 patients. Cells of SCCs were found in the fluids from only 46 patients, illustrating the infrequency of such a finding, with most of the SCC cells originating in primary neoplasms of the lung (16), female genital tract (8) or larynx (6). All of the recognized types of SCC cells were found in these fluids. Even so, SCC cells may be mistaken for cells of other neoplasms, such as adenocarcinoma and malignant mesothelioma. SCC cells in serous fluids should be identifiable if careful attention is paid to the morphologic features characteristic of SCC.

Cytopathology of follicular lesions of the thyroid gland.

Fine needle biopsy is generally considered unreliable in the differential diagnosis of follicular lesions of the thyroid gland. To test this hypothesis, we correlated fine needle biopsy diagnoses with surgical diagnoses in 379 follicular lesions. From nuclear characteristics (especially size) and the architectural pattern of tissue fragments, the following observations were made. Differentiation of goiters (including hyperplastic ones) from neoplastic thyroid disease is quite accurate and no more than 1 to 2% of cancers should be missed. The specific cytologic diagnosis of follicular carcinoma is 75% accurate, and that of follicular variant of papillary carcinoma is over 95% accurate. Of histologically proved follicular carcinomas, almost three-quarters should be diagnosed as such or strongly suspected by fine needle biopsy. The remainder will be identified as cellular follicular adenomas, reaffirming the overlap of cytologic features of benign and malignant neoplastic disease. From cytologic and surgical pathologic data for each fine needle biopsy diagnosis of follicular lesion, a probability of cancer can be stated that is useful in management decisions.