Clinicopathologic and DNA cytometric analysis of carcinoid tumors of the thymus

K. Goto et al., Clinicopathologic and DNA cytometric analysis of carcinoid tumors of the thymus, MOD PATHOL, 14(10), 2001, pp. 985-994
Citations number
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research Diagnosis & Treatment
Journal title
ISSN journal
0893-3952 → ACNP
Year of publication
985 - 994
SICI code
Twelve cases of carcinoid tumors of the thymus were reviewed in terms of cl inicopathologic, histochemical, and immunohistochemical features and DNA pl oidy patterns. The collective consisted of nine male and three female patie nts, aged 34 to 74 years, of whom five (42%) had symptoms. Eleven patients underwent surgical resection, and one with systemic metastases was autopsie d. In the 11 resected patients, tumors had invaded surrounding structures i n four cases, and mediastinal lymph node metastases were detected in six. R ecurrence occurred in two of the resected patients (18%), and the 5-year su rvival rate was 82%. Histologically, all tumors showed an organoid growth p attern with delicate fibrovascular stroma. In addition, three tumors had un usual morphologic features such as combined features of carcinoid tumor and thymoma and solid growth pattern with occasional large tumor cells. Mitoti c counts ranged from 1 to 14 per 10 high-power fields with a mean count of 4.9. Central necrosis within solid nests was observed in nine tumors. Class ification of this series using the WHO histologic classification system res ulted in categorization of all 12 tumors as atypical carcinoids. All tumors were positive for Grimelius staining and for cytokeratin. Immunohistochemi cal staining documented the presence of moderately to strongly positive neu roendocrine markers such as neuron-specific enolase, chromogranin A, synapt ophysin, and neural cell adhesion molecule. No correlation between prolifer ative activity based on the Ki67 labeling index and prognosis or lymph node metastasis was found. Concerning DNA ploidy patterns, only one tumor with multiple lymph node metastases was considered to be aneuploid. In conclusio n, although all of our cases were histologically classified as atypical car cinoid tumors of the thymus, most were diploid, and the patients enjoyed a relatively good prognosis.