The cytological findings were studied in four cases of carcinoid of digestive organs; one case each of gastric, pancreatic, small intestinal and rectal carcinoid.
The following were found cytologically; in gastric, pancreatic and rectal carcinoid, the tumor cells were arranged flat and slowed partly a trabecular, ribbon like, rosette-like formation or columnar appearance; the cytoplasm was clearly demarcated, shaped like a columnar epithelial cell or polygonal; the nucleus was round or oval in shape, and the nuclear border was smooth and thin; the nucleocytoplasmic ratio was not increased, and the size and shape were neither various; the chromatin pattern was finely granular, and exhibited an almost normal limit in distribution; the chromation arrangement was not increased in amount; thce nucleolus was small, and not prominent in shape; in general, the tumor cells were uniform.
In the case of small intestinal carcinoid, the tumor cells were scattered or overlapping, and arranged irregularly. The cytoplasmic border was unclear. The nucleus was usually round. The nucleocytoplasmic ratio was increased and anisonucleosis was observed. The nucleus was in part shaped irregular and large.
Polynucleated large cells and inclusion cells were also seen. The nucleolus was not usually prominent, but partly large and prominent. In this case, cellular atypia was more conspicuous than in the others.
It is interesting that prognosis in this case was poorer than in the others.
