A duodenal mass with biliary obstruction in a 60-year-old man

Quiz

A 60-year-old man presented with a several-month history of intermittent right upper quadrant abdominal pain. The pain was mild and self-limiting until six days before presentation, when it worsened acutely. The patient also experienced solid-food indigestion. Abdominal ultrasonography and computed tomography (CT) performed at a local clinic revealed dilatation of the gallbladder, intrahepatic ducts, and common bile duct (CBD), along with a mass-like lesion around the distal CBD. The patient was subsequently referred to our institution for further evaluation. Vital signs were within normal limits (blood pressure, 136/87 mmHg; heart rate, 86 beats/min; respiratory rate, 16/min; temperature, 36.7 °C; oxygen saturation, 97% on room air), and he was alert and in no acute distress. Laboratory studies showed a white blood cell count of 5.39×10³/μL and hemoglobin level of 12.0 g/dL. Liver function tests showed total bilirubin 5.6 mg/dL (direct bilirubin, 4.21 mg/dL), aspartate aminotransferase 170 U/L, alanine aminotransferase 254 U/L, alkaline phosphatase 421 U/L, and γ-glutamyl transferase 616 U/L. Serum carbohydrate antigen 19-9 levels were within normal limits (3.31 U/mL), and carcinoembryonic antigen levels were not elevated.

Contrast-enhanced CT revealed marked biliary dilatation with an ill-defined periampullary soft-tissue lesion and circumferential thickening of the adjacent duodenum, along with multiple slightly enlarged lymph nodes in the gastrocolic ligament, hepatoduodenal ligament, and portocaval space (Fig. 1). Upper gastrointestinal (GI) endoscopy revealed diffuse nodular friable mucosa with progressive luminal narrowing, precluding passage of the endoscope beyond the proximal second portion (Fig. 2). Considering the high-grade biliary obstruction, percutaneous transhepatic biliary drainage (PTBD) was performed (Fig. 3). A fully covered self-expandable duodenal metal stent was placed under fluoroscopic guidance to relieve the obstruction (Fig. 4). Histopathological examination of the forceps biopsy specimen obtained from the proximal second portion of the duodenum is shown in Figure 5.

Fig. 1.

Contrast-enhanced abdominal computed tomography. Coronal images demonstrate marked dilatation of the intrahepatic bile ducts and common bile duct converging on an ill-defined periampullary soft-tissue lesion, accompanied by circumferential thickening of the second portion of the duodenum. Enlarged intraperitoneal lymph nodes are also present.

Fig. 2.

Upper gastrointestinal endoscopy. (A) The duodenal bulb shows diffuse mucosal edema with a large polypoid mass. (B) The superior angle portion shows a markedly narrowed lumen with overlying whitish exudate and irregular, congested mucosa. (C) A discrete nodular elevation with friable, easily bleeding mucosa at the proximal second portion, the site of forceps biopsy. (D) The scope could not be advanced beyond the stricture at the proximal second portion.

Fig. 3.

Fluoroscopic cholangiogram obtained during percutaneous transhepatic biliary drainage, showing dilated intrahepatic bile ducts converging on a high-grade stricture of the distal common bile duct.

Fig. 4.

Fluoroscopic images obtained during duodenal stent placement. (A, B) The deployed fully covered self-expandable metal stent maintaining luminal patency across the lesion.

Fig. 5.

Histopathological and immunohistochemical findings of the duodenal biopsy (×120). (A) Hematoxylin and eosin staining showing diffuse, sheet-like infiltration of the lamina propria and submucosa by atypically large lymphoid cells, with loss of normal villous architecture. (B) CD20 immunostaining showing strong, diffuse membranous positivity in nearly all infiltrating cells. (C) CD3 immunostaining showing only scattered positive small T cells in the background, confirming that the dominant population is B lineage. (D) Ki-67 immunostaining showing a very high proliferation index (>90%).

Answer

Histopathology confirmed the diagnosis of primary duodenal diffuse large B-cell lymphoma (DLBCL). Microscopic histopathological examination of the duodenal biopsy specimen revealed diffuse infiltration of the lamina propria and submucosa by atypically large lymphoid cells with frequent mitotic figures. Immunohistochemistry revealed diffuse CD20 positivity, scattered background CD3-positive T cells, and a Ki-67 proliferation index of >90%. Immunoglobulin heavy chain gene rearrangement confirmed monoclonal B-cell proliferation, establishing the diagnosis of primary duodenal DLBCL presenting with duodenal obstruction and secondary obstructive jaundice due to periampullary infiltration. A systemic staging work-up, including bone-marrow biopsy, serum lactate dehydrogenase (LDH) measurement, and positron emission tomography (PET), revealed no evidence of extra-duodenal disease. A bone-marrow biopsy showed no evidence of marrow involvement, and the serum LDH level was within the normal range at 217 U/L (reference range, 120–246 U/L). PET imaging showed no abnormal uptake other than that at the duodenal lesion, without evidence of disseminated nodal or extranodal disease.

The patient subsequently received six cycles of R-CHOP chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) for approximately four months. The PTBD catheter was removed after resolution of the biliary obstruction. Although chemotherapy achieved disease control, the duodenal stenosis persisted. The initially placed covered self-expandable metal stent was spontaneously expelled, and the subsequently placed partially covered metal stent migrated. Because of persistent gastric-outlet obstruction and recurrent stent migration, surgical gastrojejunostomy was ultimately performed approximately 14 months after the initial presentation.

Primary duodenal DLBCL is uncommon and demonstrates a wide spectrum of endoscopic features, often mimicking epithelial malignancies. In contrast to duodenal-type follicular lymphoma, which typically presents as multiple small granular or whitish polyps, primary duodenal DLBCL has a significantly broader spectrum of endoscopic findings.1 Although large ulcerative or ulceroinfiltrative masses are the most frequently reported appearance, GI lymphoma may also present as a diffuse infiltrative disease because the tumor cells predominantly spread within the lamina propria and submucosa.2-4 The characteristic finding in the present case was not a large ulcerative mass, but a pattern of involvement. The lesion showed diffuse circumferential wall thickening extending over a long segment of the second portion of the duodenum accompanied by nodular friable mucosa and progressive luminal narrowing. Unlike duodenal adenocarcinoma, which typically presents as a localized irregular ulcerated mass with relatively abrupt margins, this lesion demonstrated diffuse longitudinal extension without a dominant ulcerative lesion. Similarly, it lacked the smooth, intact mucosal surface expected of a true subepithelial lesion. The combination of long-segment involvement, diffuse mural thickening, nodular friable mucosa, and luminal narrowing should prompt consideration of lymphoma in the differential diagnosis.2-5

Although these endoscopic findings suggest lymphoma, they are not sufficiently specific to distinguish lymphoma from adenocarcinoma or other periampullary malignancies. Endoscopic ultrasonography, when technically feasible, may help evaluate the layer of involvement and depth of mural infiltration, whereas adequate tissue acquisition with immunohistochemical analysis remains essential for a definitive diagnosis.2-4 Duodenal involvement is much less common than gastric or ileocecal disease, and presentation with obstructive jaundice caused by periampullary infiltration is uncommon.6

This case highlights the fact that primary duodenal DLBCL does not always present as a classic ulcerative mass. Recognition of diffuse long-segment infiltrative thickening with nodular friable mucosa may provide an important endoscopic clue for lymphoma and facilitate timely tissue diagnosis and appropriate treatment.