Preoperative diagnosis of a mediastinal granular cell tumor by EUS-FNA : A case report and review of the literature

Abstract

We report the first case of a posterior mediastinal granular cell tumor initially diagnosed on cytologic material obtained via endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in a 51-year-old male with a prior history of colon cancer. Aspirates obtained were cellular and composed of polygonal cells with abundant granular cytoplasm and small, round dark nuclei. An immunoperoxidase stain performed on the cell block for antibodies to S-100 protein showed strong, diffuse staining of the cytoplasmic granules. Electron microscopy performed on the cell block revealed numerous cytoplasmic lysosomes. This is the first case report in the English literature of a definitive preoperative diagnosis of a mediastinal granular cell tumor utilizing material obtained via EUS-FNA.

The Cytology of a Thyroid Granular Cell Tumor

“…The cytological findings of non-thyroid GCT have been previously described [8,9]. The tumor cells are large, containing abundant grayish, granular cytoplasms, which are very fragile, causing a dirty, granular background intermixed with naked nuclei.…”

“…Preoperative diagnosis of GCT, especially deep-seated tumors, using cytological material is difficult [9]. Cytologically, GCT should be differentiated from tumors containing cytoplasmic granules according to the anatomic location.…”

Mesenchymal tumours of the mediastinum—part II

“…GrCT occurs in the posterior mediastinum, in keeping with its proposed neuroectodermal/neural derivation. Less than 20 cases of GrCT have been reported in the mediastinum [ 1 , 4 , 8 , 15 , 40 , 76 , 87 , 95 , 98 , 117 , 137 , 159 , 168 , 170 , 179 , 184 , 185 , 224 ], including cases with malignant behaviour or atypical features suggestive of malignant GrCT [ 40 , 76 , 137 , 185 ]. Benign mediastinal GrCT occurred twice as frequently in females as in males; malignant GrCT (four cases) were equally distributed in males and females.…”

Mediastinal granular cell tumor diagnosed with endoscopic ultrasound‐guided fine needle aspiration via a modified technique based on wet suction: A case report and literature review

“…Several cases related to GCT of the mediastinum can be found in the literature, and in most the definitive diagnosis of GCT was achieved only following resection by surgical means as well as supplementary investigations (such as immunohistochemical methods and electron microscope examinations) that were carried out on sections of tissues, but only a few have been diagnosed by EUS‐FNA 11,12 . It is reported that GCT—from any body parts—can be confidently diagnoses on cytology smears, and the cellblock may be used for ancillary studies 13 .…”