Case: A 68-year-old male without medical history was referred for a colonoscopy for severe
diarrhea, hyporexia, and an 8 kg weight loss over one month.
Endoscopy: Colonoscopy revealed, 2 cm from the anal margin, a whitish 7cm neoformation ulcerated,
friable, with complete loss of the mucosal pattern, occupying nearly three-quarters
of the colorectal circumference. Pathological analysis confirmed a diagnosis of diffuse
large B-cell lymphoma, germinal center subtype (DLBCL-GCB). Subsequently, following
an episode of upper gastrointestinal bleeding, a gastroscopy was needed and revealed
a neoformation in the gastric fundus and body and duodenal ulcerations that covered
half the circumference and had an infiltrative appearance, with pathology confirming
DLBCL-GCB [1]
[2]
[3].
Discussion: Primary colorectal lymphoma is a rare entity, accounting for less than 0.5% of primary
colorectal neoplasms. The most common subtype is non-Hodgkin lymphoma, which can appear
in any part of the gastrointestinal tract, most frequently in the cecum and rectum.
Due to its nonspecific clinical manifestations, most cases are diagnosed at an advanced
stage. Endoscopic findings are highly variable, ranging from normal-appearing mucosa
to ulcerations or neoformations indistinguishable from adenocarcinoma. Therefore,
histological and immunohistochemical studies are always necessary to characterize
the type of lymphoma. The first-line treatment is chemotherapy with the R-CHOP regimen.
Prognosis depends on multiple factors, with worse survival associated with age over
65, advanced stage, and partial or no response to treatment.
