The group of 35 carcinoid tumours obtained from 34 patients was reviewed according to recent histopathological criteria. Consequently, evaluation of the Grimelius staining and immunohistochemical detection of chromogranin A (CgA), Leu-7 (CD-57), synaptophysin, neuron-specific enolase (NSE), (
-III tubulin, Ki-67 and proliferating cell nuclear antigen (PCNA) was performed. The majority of tumours (29, i.e. 83 %) were classified as typical carcinoids composed predominantly of mixed solid and trabecular or solid and tubular growth patterns. Six tumours (17 %) revealed more prominent cytological abnormalities corresponding with the diagnosis of atypical carcinoid. The majority of tumours (31, i. e. 93.9 %) showed granular cytoplasmic positivity in Grimelius staining and diffuse cytoplasmic positivity of NSE (34, i. e. 97.1 %). All of the 32 stained tumour samples showed positive immunoreactivity for synaptophysin. A high percentage of tumours (32, i. e. 91.4 %) revealed also a positive reaction with antibody TU-20 detecting (
-III tubulin, a marker of an early stage of neuronal differentiation. Thirty-four tumours (97.1 %) showed granular cytoplasmic positivity for both markers of neuroendocrine granules (CgA and Leu-7). One tumour (2.9 %) was positive only for Leu-7. Tumour cells revealed predominantly low proliferative activity evaluated by PCNA and Ki-67 immunodetection. Higher degree of proliferation was observed especially in atypical carcinoids.

        Key words: gastrointestinal carcinoids – histology – immunohistochemistry – differentiation markers – proliferation