The role of fine needle aspiration cytology in the diagnosis and management of thymic neoplasia.

BACKGROUND: Fine needle aspiration biopsy is commonly used to document the metastasis to the mediastinum. It is less often used to make the primary diagnosis of tumors, particularly thymic neoplasms. This is due to fear of sampling error, rarity of thymic tumors, multiplicity of lesions in the mediastinum, and inexperience on the part of the cytopathologist. We show that needle aspiration sampling of thymic tumors, both thymoma and thymic carcinoma, is an accurate method of diagnosis. METHODS AND RESULTS: In our series of 22 thymic tumors aspirated preoperatively and compared with the subsequent surgical resection, the accuracy of a diagnosis of thymoma was 100%, and the accuracy of a diagnosis of carcinoma was 100%. Difficulties were encountered when vague terminology was used, and insufficient information was conveyed. Immunohistochemical stains can be applied to cytologic material to aid in the identification of the epithelial and lymphocytic components of thymoma. DISCUSSION: Correlation with clinical and radiographic information is necessary, and wording of the cytology report should be as complete and clear as possible.

Immunoprofile of adenocarcinomas of the endometrium, endocervix, and ovary with mucinous differentiation.

Primary mucinous tumors of the female genital tract have morphologic features similar to primary gastrointestinal adenocarcinomas, and distinguishing these malignancies may be extremely difficult. The purpose of this study was to characterize the immunostaining patterns of tumors of the female genital tract that show mucinous differentiation using cytokeratin 7 (CK7), CK20, and CDX2 and to evaluate the usefulness of these markers in differentiating these tumors from gastrointestinal tract adenocarcinomas and also from each other. A total of 64 cases were collected, including adenocarcinomas of the ovary (n=13), endocervix (n=16), endometrium (n=34), and vagina (n=1), all of which showed predominant mucinous differentiation. Intestinal mucinous differentiation was present in 11 of the cases (6 endocervical, 4 ovarian, and 1 vaginal adenocarcinoma). All tumors were at least focally positive for CK7 with the exception of 3 cases. The majority of tumors were negative for CK20 and CDX2. However, 25% of endocervical, 24% of ovarian, and 3% of endometrial adenocarcinomas were positive for CDX2, CK20, or both. The positivity for CDX2 and CK20 correlated with intestinal differentiation: 73% of all intestinal mucinous adenocarcinomas and 4% of all Müllerian mucinous adenocarcinomas showed positivity for the hindgut markers. In 70% of the tumors positive for CK20/CDX2, the intensity of CK7 stain was stronger than the intensity of either CK20 or CDX2 stain. In conclusion, immunostaining for CK7/CK20/CDX2 is helpful in distinguishing Müllerian subtype of mucinous gynecologic tumors from lower gastrointestinal tract malignancies. In gynecologic mucinous tumors with intestinal differentiation, the overlap of staining positivity may be a limiting factor. However, a dominant CK7 staining pattern was observed.