Potential pitfalls are as follows: Lymph nodes. Contamination of a lymph node FNA by normal gastrointestinal mucosa is an important diagnostic pitfall. For example, EUS-FNA of a perigastric lymph node might produce a specimen containing sheets of normal gastric mucosa. EUS-FNA Inhibitors,research,lifescience,medical is increasingly being used for the diagnosis of gastrointestinal stromal tumors (GISTs), and other spindle cell tumors (for example, leiomyomas), as the technique permits sampling of deep-seated mural lesions. Pathologists need to be careful

to avoid over-interpreting normal gastrointestinal smooth muscle as a neoplastic process. Differentiation of GIST from other primary spindle cell tumors has important therapeutic Inhibitors,research,lifescience,medical implications; and immunohistochemical

(CD117, CD34, smooth muscle actin, muscle specific actin, S-100 protein) stains are useful for the differential diagnosis. Finally, the pathologist should remain Inhibitors,research,lifescience,medical aware that some spindle cell neoplasms of the gastrointestinal tract may be metastatic lesions; spindle cell melanoma is a classic example of a metastatic lesion Inhibitors,research,lifescience,medical that may be misinterpreted as GIST. Summary Interest in gastrointestinal

cytology has mirrored technical advances in this field over the last few decades. These advances allow the visualization of and simultaneous brushing of abnormal mucosa, obtaining needle aspirates and excising mucosal biopsy samples for pathologic evaluation. The use of EUS-FNA now helps in the diagnosis Inhibitors,research,lifescience,medical of submucosal and deeper seated lesions, preoperative staging of gastrointestinal tract malignancies, and determining further management of patients. EUS-FNA has thus revolutionalized the practice of gastrointestinal medicine and is rapidly becoming the technique of choice for sampling deep-seated all lesions that were previously accessible only by laparotomy. Such advances have brought pathologists to the forefront for the management of gastrointestinal tract lesions. These newer techniques have also presented ACY-1215 chemical structure challenges for pathologists. They can be time-consuming and therefore require an organized endoscopy service with good communication between endoscopist and pathologist so that the demands on the pathology laboratory and the pathologist’s time are minimized. There are also important issues related to reimbursement.