HANDLING OF PATHOLOGICAL SPECIMENS AND INTERPRETATION OF PATHOLOGICAL DIAGNOSIS IN GASTROENTEROLOGICAL ENDOSCOPY

Abstract

The endoscopist plays an important role in pathological diagnosis because the endoscopist collects tissue samples. Biopsied specimens should be immediately fixed, while endoscopically resected specimens should be properly stretched, pinned on a board, and fixed. Recently, fixation with 10％ neutral buffered formalin has been recommended for examination of protein expression and/or gene mutation. In endoscopically resected specimens, the depth of tumor invasion, histology, infiltration pattern, lymphovascular invasion, and excision margin are commonly evaluated, and these findings are necessary to determine whether endoscopic treatment is completed or whether additional excision is needed. On the other hand, there are several organ-specific aspects such as Lugolʼs staining (esophagus), identification of the esophagogastric junction, mixed-type histology (stomach), and tumor budding (large intestine). The handling of pancreatic tissue obtained by endoscopic ultrasound-guided fine needle aspiration requires cooperation from multiple individuals including the endoscopist, nurse and cytotechnologist, and the combined use of histological and cytological examinations is useful for making an accurate diagnosis. As a result of additional resection after diagnosis of the endoscopically resected specimen, most patients have neither residual cancer nor lymph node metastasis. It is necessary to improve the evaluation of predictive factors related to the risk of metastasis and/or recurrence. This warrants detailed examination, and cooperation between endoscopists and pathologists is indispensable.