Hidden Malignancy: Ileocecal Intussusception as an Atypical First Presentation of Diffuse Large B-cell Lymphoma in Adulthood

Abstract

Intussusception is predominantly a pediatric condition, with only about 5 % of all intussusception cases occurring in adults with primary intestinal lymphomas comprising 1 %–4 % of gastrointestinal malignancies, 90 % of which are B-cell non-Hodgkin lymphomas (NHL). Diffuse large B-cell lymphoma (DLBCL), the most common subtype of NHL, often leads to intussusception without classical B symptoms. We present the case of a 33-year-old male with ileocolonic intussusception caused by a 4.8 × 5.3 × 5.5 cm enhancing mass. Histopathology and FISH confirmed DLBCL without MYC, BCL2, or BCL6 rearrangements, ruling out double- or triple-hit lymphoma. Following a right ileo-colectomy, R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy was initiated. This case underscores the role of malignancy in intussusception and highlights the importance of timely diagnosis and management.

1. Introduction/Background

Intussusception is defined as the invagination of a proximal intestinal segment into the lumen of a distal intestinal segment. It accounts for 1 %–5 % of all intestinal obstructions in adults.1 Adult intussusception is an unusual but serious gastrointestinal (GI) event, often serving as a sentinel of underlying malignancies. The condition’s mild and non-specific clinical signs contrast sharply with its potential to cause catastrophic outcomes, necessitating accurate diagnosis and prompt management. 2 A lead point is frequently the underlying trigger for intussusception, often arising from a mass that may be either benign or malignant, such as in cases of lymphoma. The gastrointestinal tract represents the most commonly involved extranodal site in lymphoma, accounting for approximately 5 %–20 % of cases.3 Histological studies show that B-cell NHL account for more than 90 % of primary gastrointestinal lymphomas. The highest rates of involvement are found in the stomach (50 %–60 %), small intestine (20 %–30 %), and colon (10 %–20 %). Although it is a rare presentation of NHL, DLBCL is the most common malignancy causing intussusception.4 Here, we present a rare case of diffuse large B-cell non-Hodgkin lymphoma causing intussusception.

2. Case description

A 33-year-old Caucasian male with a past medical history of appendectomy, gastroesophageal reflux disease, and hypertension presented to the emergency department with sharp, intermittent epigastric abdominal pain for one month. The onset of the pain was gradual, moderate in intensity, and radiated toward the right lower quadrant, with no associated nausea, vomiting, or constipation. The pain was neither improved nor relieved by any factors. The intensity of the pain increased over the past couple of days, prompting him to seek care in the emergency department. He reported having normal bowel movements, although he mentioned experiencing some blood in his stools about six weeks ago. He denied fever, night sweats, or unintentional weight loss. Laboratory studies were unremarkable except for mild leukocytosis (12.54 × 10³/μL) with isolated neutrophilia and normocytic anemia. On physical examination, there was generalized abdominal tenderness.

A Computed Tomography scan abdomen and pelvis with Intravenous contrast (Fig. 1) showed surgical changes in the right lower quadrant consistent with a prior appendectomy. There was an area of colonic intussusception in the right mid-abdomen, with prominent bowel wall thickening and a solid enhancing mass measuring 4.8 × 5.3 × 5.5 cm within the lumen of the ascending colon. The patient subsequently underwent exploratory laparotomy, and a right ileo-colectomy was performed. Gross examination of the specimen revealed an exophytic mass measuring 6.5 × 4.8 × 3.7 cm. The mass invaded beyond the serosal surface. A total of nine mesenteric lymph nodes were identified, ranging in size from 0.3 to 1.5 cm in greatest dimension.

Fig. 1.

Coronal CT image of the abdomen and pelvis demonstrating colonic intussusception in the right mid-abdomen. There is associated bowel wall thickening, pericolonic fat stranding, and a well-defined enhancing intraluminal mass within the ascending colon measuring approximately 4.8 × 5.3 × 5.5 cm, suggestive of a potential lead point.

Microscopic examination revealed diffuse large B-cell lymphoma. The tumor cells were negative for pan-keratin but positive for CD45, CD20, and PAX5, consistent with diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS). Figs. 2 and 3 show the immunohistochemical analysis. High-grade fluorescence in situ hybridization (FISH) analysis was performed, which showed no MYC/IgH/CEN8 t(8;14), MYC (8q24), BCL2 (18q21), or BCL6 (3q27) rearrangements, thereby excluding the diagnosis of double- or triple-hit lymphoma. A Positron Emission Tomography Scan-CT scan revealed no abnormalities at baseline. An oncologist was consulted, and the R-CHOP regimen was initiated.

Fig. 2.

Hematoxylin and Eosin stain (×40). Diffuse proliferation of the large tumor cells with prominent nucleoli (black arrows). Normal lymphocytes shown for comparison (red arrows).

Fig. 3.

Immunohistochemical stain for (IHC) for BCL6. The tumor cells are diffusely positive (nuclear staining).

3. Discussion

Abdominal pain, nausea, vomiting, hematochezia, diarrhea, and constipation are some of the nonspecific symptoms that frequently accompany intussusception. In adults, it usually develops gradually and presents with symptoms similar to intestinal obstruction. The most prevalent symptom is abdominal pain, which often manifests intermittently, making diagnosis difficult and delaying treatment.1,3 Bowel intussusception is approximately 20 times more common in children than in adults. In adults, it accounts for only 1 % of all intestinal obstructions and less than 5 % of all intussusception cases. Additionally, it is a rare finding during abdominal surgeries, occurring in fewer than 1 in 1300 procedures. Notably, unlike many gastrointestinal conditions that show a gender predominance, intussusception occurs with equal frequency in both men and women, which is relatively uncommon and noteworthy in clinical epidemiology. When it does occur in adults, it is most often seen in individuals over the age of 50.8

In adults, intussusception most commonly originates in the small bowel, with benign lesions accounting for approximately 50 %–75 % of cases. Notably, up to 90 % of adult cases have a clearly identifiable pathological lead point. In this instance, DLBCL was determined to be the underlying cause, highlighting the importance of maintaining a high level of suspicion when assessing adult patients with intussusception.9 This case illustrates the diagnostic complexity that can arise when patients present with chronic, vague abdominal symptoms in the absence of classic red flags such as fever, weight loss, or night sweats. The patient’s young age and lack of B symptoms initially reduced suspicion for malignancy. Furthermore, his prior surgical history (appendectomy) and unremarkable labs, aside from mild leukocytosis and anemia, could easily mislead clinicians toward more benign explanations.

Clinicians should be alert to subtle changes in symptom patterns―such as increasing intensity or new localization of abdominal pain―as these may warrant advanced imaging even in the absence of systemic signs. Early CT imaging in this patient was crucial in uncovering the true underlying pathology. Diagnosis is typically established using CT imaging, which offers a sensitivity range of 58 %–100 %. Surgical resection remains the preferred treatment approach. When a malignancy is identified as the underlying cause, proper staging―including tissue biopsy and PET/CT―is essential before initiating chemotherapy.2

DLBCL, as the most common type of NHL, frequently presents with aggressive symptoms and can involve extranodal sites, including the gastrointestinal tract. Although it is rare for DLBCL to present as intussusception, it is crucial to recognize this possibility, especially when imaging and histological findings suggest malignancy.7 The exclusion of MYC, BCL2, and BCL6 rearrangements through FISH (Fluorescence In Situ Hybridization) analysis is essential for differentiating standard DLBCL from more aggressive double- or triple-hit lymphomas, thereby guiding appropriate treatment strategies6

The R-CHOP regimen, comprising rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, is the standard treatment for DLBCL and has demonstrated efficacy in improving patient outcomes.5,10 The patient’s response to this regimen will be monitored through follow-up imaging and clinical assessments to evaluate treatment effectiveness and manage potential side effects.

This case highlights the importance of considering malignancy in the differential diagnosis of intussusception. Comprehensive diagnostic approaches―including imaging, histopathology, and FISH analysis―are critical for accurate diagnosis and effective treatment planning. The use of standard treatment regimens like R-CHOP aligns with established protocols for managing DLBCL and illustrates the importance of multidisciplinary care in complex cases.

4. Conclusion

This case highlights the diagnostic challenges posed by vague gastrointestinal symptoms in a young adult. Despite the lack of classic lymphoma features, cross-sectional imaging uncovered a malignant lead point causing intussusception. Comprehensive diagnostic approaches―including imaging, histopathology, and FISH analysis―are critical for accurate diagnosis and effective treatment planning. The use of standard treatment regimens like R-CHOP aligns with established protocols for managing DLBCL and illustrates the importance of multidisciplinary care in complex cases.