Role of computed tomography in gastrointestinal lymphoma: diagnosis, monitoring and complications

Introduction

Gastrointestinal lymphoma accounts for 5-20% of extranodal lymphomas, with the following segments affected, in the descending order of frequency: stomach, ileum, jejunum, duodenum and colon^(1-3). Patients typically present with nonspecific symptoms, leading to a delayed diagnosis. The most common symptoms include epigastric pain, weight loss and anorexia. Additionally, gastrointestinal bleeding, palpable abdominal masses and intestinal perforation may also be observed^(3,4). The diagnosis primarily relies on histopathological examination of biopsy samples obtained via upper or lower gastrointestinal endoscopy^(2,5). Imaging plays a crucial role in diagnosing and monitoring patients with gastrointestinal lymphoma. It aids in differentiating it from other gastrointestinal tumors, which require distinct treatments and have varying prognoses. More­over, imaging helps identify complications such as perforations, obstructions or gastrointestinal fistulas^(4,6,7). Hybrid imaging techniques like FDG-PET-CT (fluorodeoxyglucose positron emission tomography–computed tomography) are essential for staging and evaluating the therapeutic response of lymphomas according to the Lugano criteria. Contrast-enhanced CT serves as a complementary investigation, providing additional diagnostic information^(8-12).

Case report

A 55-year-old female patient, with no significant personal or family medical history, presented with progressive periorbital edema over the past six months, initially affecting the right side before becoming bilateral. Additionally, she reported abdominal distension, asthenia and an unintentional weight loss of approximately 10 kg over the past year. Laboratory tests at admission revealed severe microcytic hypochromic anemia (Hb 3.7 g/dL, MCV 60 fL), grade II lymphopenia (450/mL), and normal platelet levels. Immunochemical analysis showed elevated IgM levels (15.2 g/L) and an increased kappa/lambda ratio (5.35). Electrophoresis demonstrated a mild, non-quantifiable banding in the gamma1 region and a compact banding in the gamma2 region corresponding to 0.5 g/dL. A contrast-enhanced CT scan of the chest, abdomen and pelvis revealed circumferential and relatively symmetrical parietal thickening of the terminal ileum and cecum, accompanied by secondary aneurysmal dilation (Figure 1). Bilateral periorbital soft tissue masses (Figure 2), splenomegaly, multiple confluent retroperitoneal lymphadenopathies, a right lumbar subcutaneous tissue nodule, and a pelvic soft tissue mass in the right iliac fossa (Figure 3) were also identified.

An excisional biopsy of a left inguinal lymph node was performed, with histopathological and im­­mu­no­his­to­che­­mi­­cal findings confirming a small B-cell marginal zone lymphoma with follicular colonization and secondary follicular helper T-cell hyperplasia. The patient was started on immunochemotherapy following the R-CHOP protocol. After three cycles, an abdominal ultrasound revealed tumor progression, prompting a switch to R-GEMOX therapy (rituximab 500 mg, gemcitabine 1400 mg, oxaliplatin 140 mg) with G-CSF administration. A subsequent abdominal CT scan demonstrated a large intraperitoneal fluid collection (Figure 4A). The patient was discharged at her request, but she was readmitted three weeks later for the drainage of the intraabdominal collection (Figure 4B), which was confirmed as an intraabdominal abscess through fluid analysis.

Following drainage, chemotherapy was temporarily halted until the resolution of the infectious process. Shortly after, the patient presented with an intestinal obstruction, confirmed by emergency CT imaging (Figure 5). The patient underwent a surgical procedure, during which extensive intraabdominal adhesions were identified, leading to an obstruction secondary to a dense fibrous band.

The patient subsequently resumed chemotherapy without further complications. Follow-up CT scans demonstrated a reduction in the size of the ileocecal thickening (Figure 6), along with decreased splenomegaly, lymphadenopathy and secondary lesions.

Discussion

The small intestine is primarily evaluated using endoscopic methods (upper gastrointestinal endoscopy, colonoscopy, or capsule endoscopy) or imaging techniques^(1,13). Traditional radiological methods such as enterography and enteroclysis have largely been abandoned due to their limitations in detecting subtle intestinal wall changes⁽¹⁴⁾. Advanced imaging techniques like entero-CT/MR play a crucial role in evaluating small bowel tumors due to their high spatial resolution, which allows for the direct visualization of the intestinal wall and adjacent structures^(15-17). These techniques involve the administration of neutral oral contrast to delineate the intestinal wall following intravenous contrast injection, with the density of the contrast medium opposing that of the enhanced intestinal wall^(13,17). The distal ileum is the second most common site of extranodal lymphoma, after the stomach⁽¹¹⁾. Imaging findings in ileal lymphoma vary widely, with presentations ranging from polypoid/nodular, infiltrative, aneurysmal, exophytic mass-like or, rarely, stenotic lesions⁽¹¹⁾. Our case highlights an aneurysmal form of intestinal lymphoma, observed in approximately one-third of cases. This occurs due to mesenteric plexus destruction, muscular layer infiltration leading to loss of contractility, or vascular invasion causing ischemic necrosis and secondary dilation⁽¹¹⁾. Imaging is essential not only for diagnosing and staging intestinal lymphoma, but also for differentiating it from inflammatory bowel diseases (e.g., Crohn’s disease, ulcerative colitis, tuberculosis) and other tumors – e.g., adenocarcinoma, gastrointestinal stromal tumors (GISTs) and neuroendocrine tumors (NETs). The differential diagnosis is based on intestinal wall involvement patterns, presence/absence of lymphadenopathy, and associated complications^(11,18,19). Complications of intestinal lymphoma include ulceration, hemorrhage, perforation, and fistula formation, while intestinal obstruction is rare, usually resulting from intussusception or significant parietal thickening^(11,12). Our case underscores the importance of CT imaging in monitoring complications in patients with intestinal lymphoma and in correlating the imaging findings with the clinical history to distinguish primary obstructive causes (e.g., lymphoma, rarely) from secondary causes (e.g., postoperative adhesions). The mainstay of treatment for intestinal lymphoma is anthracycline-based chemotherapy (CHOP) combined with the anti-CD20 monoclonal antibody rituximab, which has shown favorable remission and survival outcomes^(19,20). Studies provide mixed results regarding the necessity of surgical treatment, with most highlighting its role in emergency situations, while some advocate for primary surgical intervention, particularly for colonic lymphoma^(19,21). This case emphasizes the value of CT evaluation not only for diagnosis and staging (alongside FDG-PET-CT) but also for identifying complications and guiding timely surgical intervention when necessary. Thus, CT proves invaluable in the comprehensive management of intestinal lymphoma, from the initial diagnosis to treatment response monitoring and postoperative follow-up.

Conclusions

Gastrointestinal lymphoma poses diagnostic and therapeutic challenges due to its variable presentation. CT plays a pivotal role not only in initial assessment and treatment response evaluation, but also in detecting complications requiring surgical intervention. This case underscores the importance of integrating imaging into a multidisciplinary approach for optimal patient outcomes.   

Corresponding authors: Robert-Mihai Enache E-mail: robert-mihai.enache@rez.umfcd.ro;  Ioana-Gabriela Lupescu E-mail: ioana.lupescu@umfcd.ro

Conflict of interest: none declared.

Financial support: none declared.

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