B.R. Valitov¹, B.I. Gataullin1–3, A.I. Ivanov1–3, I.G. Gataullin1, 3, A.A. Valiev¹, Ya.F. Shamsutdinova1, 2, Z.M. Toichuev1
1Republic Clinical Oncological Dispensary named after Prof. M.Z. Sigal, Kazan
2Kazan Federal University, Kazan
3Kazan State Medical Academy — branch of the Russian Medical Academy of Continuing Professional Education, Kazan
Gataullin B.I. — PhD (Medicine), Associate Professor of the Department of Surgery
76 Karl Marks St., 420012 Kazan, tel.: +7-962-553-31-08, e-mail: bulatg@list.ru, ORCID ID: 0000-0003-1695-168X
Abstract. Colorectal cancer (CRC) remains one of the leading causes of cancer morbidity and mortality. Early diagnosis and accurate staging are crucial for choosing the optimal treatment strategy. Endoscopic ultrasonography (EUS) combined with colonoscopy (EUS-colonoscopy) allows for endoscopic examination with ultrasound imaging and assessment of the depth of tumor invasion, involvement of the intestinal wall and regional structures.
The purpose — to demonstrate the diagnostic capabilities and advantages of endoscopic ultrasonography combined with fibrocolonoscopy (EUS) in detecting colorectal neoplasms, using a series of clinical cases.
Material and methods. The study was conducted at the Republic Clinical Oncology Dispensary (Kazan, Russia) and included three clinical cases of rectal neoplasms with different histological types (MALT lymphoma, adenocarcinoma, and adenomatous polyp). All patients underwent standard clinical and instrumental examinations, including EUS with a radial 5–10 MHz probe, followed by histological and immunohistochemical verification.
Results. EUS-FCS accurately determined the depth of tumor invasion and the local extent of the disease, which clarified the stage and guided treatment decisions. In Case 1, EUS allowed the diagnosis of primary extranodal rectal MALT lymphoma (stage IE); in Case 2, invasive adenocarcinoma (pT2N1M0) was confirmed; in Case 3, a benign adenomatous polyp without submucosal invasion was verified.
The accuracy of EUS in determining the depth of invasion (T-stage) reaches 85–90%, exceeding that of CT and MRI for early stages. The method is particularly valuable for differentiating between T1–T2 and T3 lesions. EUS is relatively affordable and less time-consuming than MRI but requires specialized equipment and trained personnel. The findings are consistent with both international and Russian clinical guidelines (Ministry of Health of the Russian Federation, RUSSCO), which recommend EUS for preoperative assessment and planning of local excision in early rectal cancer.
Conclusion. EUS is a highly informative and accessible method of diagnosing and staging rectal tumors. It complements conventional imaging techniques (MRI, CT), improves preoperative staging accuracy, facilitates individualized surgical planning, and enhances treatment outcomes in patients with colorectal cancer. The presented experience supports the feasibility of wider implementation of EUS in routine colorectal oncology practice.
Key words: colorectal cancer, differential diagnosis, ultrasonography, endoscopy, clinical case