Keywords
mantle cell lymphoma - multiple lymphomatous polyposis - non-Hodgkin’s lymphoma
Introduction
Mantle cell lymphoma (MCL) is a subtype of B-cell non-Hodgkin’s lymphoma (NHL) and
comprises 2 to 7% of all NHL characterized by chromosomal translocation t (11;14)
(q13; q33) with resultant overexpression of cyclin D1. The gastrointestinal (GI) tract
is one of the most common extranodal sites and accounts for 5 to 20% of all extranodal
involvement[1] and typically manifests as multiple lymphomatous polyposis (MLP).[2]
[3] MLP most commonly occurs in the ascending colon and the small bowel, particularly
in the ileum and ileocecal region and is characterized by multiple sessile polypoidal
lesions, sometimes the entire GI tract being carpeted with numerous polyps.
Case Report
A 58-year-old female with no pervious comorbidities presented with complaints of abdominal
pain of 6-month duration with unintentional weight loss of around 10 kg, bleed per
rectum, and night sweats. On physical examination, she had pallor. Per abdomen exam
showed a nontender mass of about 10 × 8 cm in the left iliac fossa. Her spleen was
palpable, and per rectal exam showed a firm nodularity.
Her laboratory workup was significant for microcytic hypochromic anemia with a hemoglobin
of 8.9 g/dL and an erythrocyte sedimentation rate of 96. Her lactate dehydrogenase
was elevated at 389 U/L. Ultrasound of the abdomen/pelvis showed a large lobulated
hypoechoic lesion (12.5 × 13 × 8 cm) in the suprapubic region and left iliac region
extending into the pelvis. Also noted were multiple paraaortic and paracaval lymph
nodes with a spleen measuring 14 cm. The findings on computed tomography abdomen and
pelvis were consistent with lymphoma involving terminal ileum with multiple polyps
of the large bowel loops, omental lesions, and wall thickening of ileal loops ([Fig. 1]).
Fig. 1 CT abdomen and pelvis showing circumferential irregular soft tissue mass involving
long segments of the distal ileum with aneurysmal dilatation of the lumen. Numerous
variable sized polypoidal lesions noted diffusely scattered in the right colon, transverse
colon, and proximal descending colon. Also, hepatomegaly and borderline splenomegaly
with extensive discrete paraaortic and mesenteric lymph nodes noted.
Colonoscopy ([Fig. 2]) demonstrated the entire colon to be carpeted with multiple polypoidal lesions of
varying sizes (0.5–2 cm). Histopathology of the colonic polyps showed diffuse infiltration
of the colon by small- to medium-sized lymphocytes ([Fig. 3]). Immunohistochemistry (IHC) showed the lymphoid cells to be uniformly positive
for B-cell marker CD20 and for Bcl2 and cyclin D1 which confirmed the diagnosis of
MCL. Ki67 index, which is a proliferative index, was 20 to 25% ([Fig. 4]).
Fig. 2 Colonoscopy showed the entire large bowel to be carpetted with multiple polypoidal
lesions of varying sizes. On snare polypectomy, cheesy white material was noted exuding
from the polyps.
Fig. 3 Patchy eosinophil rich inflammation with widely spaced crypts intervened by sheets
of lymphoid cells with several lymphoepithelial lesions.
Fig. 4 Immunohistochemistry of the tumor cells showing cyclin D1, CD20, and Bcl2 positivity.
The patient was initiated on chemotherapy consisting of R-CHOP regimen (rituximab,
cyclophosphamide, doxorubicin, vincristine, and prednisone) which resulted in remarkable
tumor regression and amelioration of her symptoms.
Discussion
Primary GI lymphomas are rare and can involve any segment of the GI tract from the
oropharynx to the rectum. MCL is a subtype of B-cell lymphoma typically manifesting
as MLP. MLP, first described by Cornes in 1961,[2] is characterized by multiple polypoidal lesions consisting of uniform infiltrates
of malignant B cells. Patients with MLP typically present with abdominal pain, hematochezia,
diarrhea, weight loss, and night sweats.[4] Diagnosis of this condition requires a combination of endoscopic findings with histopathological
analysis and IHC. The typical endoscopic features are nodular or polypoid lesions
ranging from 2 to 10 mm in diameter. Immunophenotypic analysis is essential to distinguish
MCL from other lymphomas and shows positivity for cyclin D1, CD20, CD79a, and CD5
and negativity for BCL16, CD23, and CD10. In general, patients with MCL tend to have
a poorer outcome than those with other low-grade NHL with a 5-year survival rate of
around 11%.[5] The current treatment regimen recommended for MCL is R-CHOP induction regimen and
high dose of cytarabine followed by high-dose consolidation and autologous stem cell
transplant.[6]
In conclusion, although GI lymphomas are rare entities, MCL should be included in
the differential diagnosis of patients presenting with endoscopic findings of multiple
polypoidal lesions. A combination of endoscopic, imaging, and histopathologic examination
with IHC clinches the diagnosis of MCL.
