Diagnostic findings of ultrasound‐guided fine‐needle aspiration cytology for gastrointestinal stromal tumors: Proposal of a combined cytology with newly defined features and histology diagnosis

Abstract

Recently, endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) has been applied for diagnosis of gastrointestinal submucosal tumors. There have been no definite criteria, however, for the adequate cytological diagnosis of gastrointestinal stromal tumor (GIST) in practice. To facilitate this a novel method is proposed that combines cytology and histology. For 49 cases of submucosal tumor of gastrointestinal tract, EUS-FNA was performed. The aspirated materials were processed for cytology and histology. Both cytological and histological findings were examined on immunocytochemical and immunohistochemical staining of c-kit. Of 49 cases, 40 (81.6%) proved adequate for cytological and/or histological examination. On cytology, cluster types were classified into type A (piled clusters with high cellularity showing a fascicular pattern), type B (thin layered clusters with high cellularity showing a fascicular pattern), and type C (mono-layered clusters or scattered cells). Types A and B were strongly associated with histological diagnosis of GIST. Type C clusters needed confirmation on c-kit positivity and histology. Thus, the combined cytology with newly defined features, and classification and histological diagnostic method for EUS-FNA materials can contribute to improved routine diagnosis for GIST.

Cytological Findings of Gastrointestinal Stromal Tumor-Derived Bone Metastasis

“…In addition, the characteristic cytological findings of GIST have already been well described, and they do not differ markedly from our findings [12, 14, 15]. In particular, marked pleomorphism is not seen in cases of GIST-derived bone metastasis.…”

Endoscopic Ultrasound-Guided Fine Needle Aspiration in Submucosal Lesion

“…Diagnosis is done with smear cytology, histology, and immunohistochemical staining of the cell blocks 4. Yoshida et al8 proposed several preparation methods of EUS-FNA specimen for good results. First, maintaining negative pressure of needle many times is necessary to get sufficient tissue because GIST cells have tight cell to cell adhesion.…”

“…In handling specimens by EUS-FNA in GISTs, it is important to prepare aspirated tissues for cytology and histology in two ways 8. In cases of SMTs, aspirated materials using EUS-FNA were processed for cytology and histology including immunocytochemical and immunohistochemical staining for C-KIT, and 81.6% of the cases were found adequate for cytological and histological examinations.…”

“…About 95% of GISTs have a positive reaction for C-KIT on immunohistochemistry, and 78% to 88% have mutations of the c-kit gene 8. Molecular analysis for c-kit mutation can be done on cell block materials from EUS-FNA 5…”

Diagnosis of an Accessory Spleen Mimicking a Gastric Submucosal Tumor Using Endoscopic Ultrasonography-guided Fine-needle Aspiration

“…[14][15][16][17] To date, there are no reports describing the use of EUS-guided FNA for diagnosing an accessory spleen mimicking a gastric SMT which is located on the fourth layer of the stomach in EUS findings.…”