Endorectal Ultrasound Guided Fine Needle Aspiration (ERUS-FNA): A Diagnostic Tool for Immunohistochemical and Molecular Studies in Rectal and Perirectal Lesions.
Zahra Maleki, Yener Erozan, Qing Kay Li. The Johns Hopkins Hospital, Baltimore, MD
Background: Currently, the targeted therapy demands molecular study of the tumors in addition to an accurate morphological diagnosis. Colorectal endoscopic brushing and CT/ultrasound-guided FNA is commonly used in diagnosing and staging of colorectal and perirectal cancers. Endorectal ultrasound (ERUS) represents one of the most significant developments in endoscopy over the past 20 years. It allows highly detailed assessment of the gastrointestinal wall layers as well as visualization of the extraluminal structures. Furthermore, ERUS-FNA is gaining more clinical attention for obtaining material for molecular studies of tumors. Herein, we have reviewed the utility of ERUS-FNA in diagnosing of cancers and providing samples for immunohistochemical (IHC) and molecular studies in cancer patients.
Design: 47 perirectal FNAs were retrospectively retrieved from the cytopathology archives of a major academic medical center over a period of 20 years. 20 CT or ultrasound guided FNA cases were excluded. The cytomorphologic features of those 27 ERUS-FNA cases along with their corresponding histology were correlated with ancillary studies including IHC, and clinical information.
Results: The patients' age ranged from 17 to 79 years (mean=51.5 years), with a male to female ratio of 10:11. Among 27 ERUS- FNA cases, there were 3 cystic and 24 solid masses. The aspirated site included perirectal lymph nodes (n=7) and perirectal soft tissue (n=20). Metastatic carcinoma detected in 4 lymph nodes. Two lymph nodes were benign and one was non-diagnostic. Soft tissue FNAs showed carcinomas (n=9), benign glandular epithelium (n=9), one case diagnosed as cellular atypia and one was non-diagnostic. Past medical history of 18 cases was significant for carcinoma. The primary site of the tumors included colorectal, urinary bladder, prostate, pancreas, ovary and lower female genital tract. Multiple IHC stains were performed on cell block of 3 cases.
Conclusions: ERUS-FNA is a valuable diagnostic tool in diagnosing of perirectal lesions. ERUS-FNA can be utilized for 1) appropriately staging of cancer patients by evaluation of nodal metastasis or local tumor spread particularly in colorectal adenocarcionmas, 2) prevention of unnecessary surgical intervention in benign conditions, 3) providing diagnostic material for molecular and IHC studies.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 58, Tuesday Morning