Benign and malignant tumors of the rectum and perirectal region

Abstract

Although most rectal masses are histologically characterized as adenocarcinomas, the rectum and perirectal region can be affected by a wide variety of tumors and tumor-like conditions that can mimic the symptoms caused by rectal adenocarcinoma, including mucosal or submucosal rectal tumors such as lymphoma, gastrointestinal stromal tumor, leiomyosarcoma, neuroendocrine tumor, hemangioma, and melanoma, as well as tumors of the perirectal region such as developmental cyst, neurogenic tumor, osseous tumor, and other miscellaneous conditions. As a group, tumors of the rectum are considerably different from the group of tumors that arise in the perirectal region: they are most often neoplastic, symptomatic, and malignant, whereas tumors arising in the perirectal region are most commonly congenital, asymptomatic, and benign. Proctoscopy with biopsy is the most important method for the diagnosis of rectal tumors, but this procedure cannot determine the precise intramural extension of a rectal tumor and cannot accurately distinguish submucosal and intramural tumors from extramural tumors. Cross-sectional imaging, especially transrectal ultrasound and magnetic resonance imaging, allows evaluation of the entire bowel wall thickness and the perirectal tissues, helping further characterize these tumors. Recognition of the existence of these masses and their key clinical and imaging features is crucial for clinicians to accurately diagnose and appropriately manage these conditions.

Ectopic Prostatic Tissue in the Rectum: A Case Report

“…Moreover, a tailgut cyst usually presents adhering to the sacrum or rectum and has a multilocular shape, and as the internal protein concentration increases, the signal intensity will increase on T1WI and decrease on T2WI (6,7). In premenopausal women with endometriosis, usually affecting the anterior wall of the rectum, it shows hyperintensity on both T1WI and T2WI and obliterates the normal hyperintense fat plane between the uterus and the rectum on T2WI (6,7). With a recent history of infection, retrorectal abscess formation is possible.…”

Beyond hepatic hemangiomas: the diverse appearances of gastrointestinal and genitourinary hemangiomas

“…The majority of patients have concomitant cutaneous hemangiomas [59]. As in the small bowel, there is a reported male predominance [62][63][64]. The types and gross appearance are similar to the small bowel, with cavernous hemangiomas being the most prevalent [39].…”

“…Endoscopy is sometimes unable to detect hemangiomas [63]. When vessels are thrombosed, mucosal edema and inflammatory changes are often present and may be mistaken for proctitis [62,63].…”

Application of Endorectal Ultrasound in Evaluation of Anorectal Diseases

“…ERUS is very helpful for the follow up of this neoplasm during the treatment of RCT, because it can identify or exclude persistent or recurrent disease. Needle core biopsies under ultrasound guidance can be obtained to identify the persistent masses or abnormalities following treatment [89] . Under the enteroscope, intramural lesions or extramural compression from a pathologic process or an anatomic aberration causing subepithelial compression appear as a rectal subepithelial lesions.…”