Polipose linfomatosa múltipla do trato gastrointestinal

Martins C, Teixeira C, Gamito E, Ribeiro S, Trabulo D, Cardoso C, Mangualde J, Freire R, Alves AL, Cremers I, Oliveira AP
Serviço de Gastrenterologia, Hospital de São Bernardo, Setúbal, Portugal
Multiple Lymphomatous Polyposis of the Gastrointestinal Tract
Primary gastrointestinal lymphomas represent up to 10% of all gastrointestinal tumors and the most common histological types are mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma. Mantle cell lymphoma is a rare malignancy with unique biological, pathological and clinical features, which comprises approximately 2.5-7% of all non-Hodgkin lymphomas. Gastrointestinal tract involvement by this neoplasm with distinguished multiple lymphomatous polyposis is very rare. Herein, we report an uncommon case of mantle cell lymphoma presenting as multiple lymphomatous polyposis of the small and large bowel in a 62-year-old female who was referred to our Department due to anemia and positive fecal occult blood test. 
Case Report
We report a 62-year-old caucasian female referred to our Department due to anemia and a positive fecal occult blood test. The patient presented with a 2-months clinical picture of mild diffuse abdominal pain, change in bowel habits including loose stools, significant involuntary weight loss, anorexia and asthenia. Physical examination showed pallor, painless splenomegaly and a palpable mass in the right iliac fossa. Initial laboratory tests showed microcytic and hypochromic anemia (hemoglobin 7.6 g/dL), mild thrombocytopenia (125x109/L) and high LDH (399 U/L). Upper gastrointestinal endoscopy showed small pseudopolypoid lesions on the duodenal bulb (Figure 1A). Total colonoscopy revealed multiple sessile polypoid lesions, ranging from 4 to 25mm in greater dimension, some with subepithelial appearance and others with surface ulceration, along the entire length (Figure 1B,C,D,E,F).
Figure 1. Endoscopic findings. (A) Small pseudopolypoid lesions on the duodenal bulb; (B,C,D,E,F) Multiple sessile polypoid lesions of different sizes throughout the colon; (F) Polypoid lesion with ulcerated surface

Endoscopic biopsies samples of duodenal and colonic lesions showed diffuse infiltration of the intestinal wall by atypical lymphocytes (Figure 2 A,B), positive for cyclin D1 (Figure 2C) and negative for CD3, on immunohistochemistry. Therefore, these findings supported a diagnosis of mantle cell lymphoma presenting as multiple lymphomatous polyposis.
Figure 2. Histopathological features of the lymphoma. (A,B) Diffuse intestinal mural infiltration of tumor cells (A – H&E x 40; B – H&E x 100); (C) Neoplastic cells were strongly positive for Cyclin D1 (IHC x 100)
The subsequent workup revealed advanced disease with thickening of several segments of the small and large intestinal wall (Figure 3A), multiple mesenteric adenopathies, hepatosplenomegaly (Figure 3B) and bone marrow lymphomatous involvement (Ann Arbor stage IVB). The patient underwent immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) with partial response so far.
Figure 3. Images on abdominal CT scan. (A) Prominent thickening of the terminal ileum; (B) Homogeneous splenomegaly

Endoscopic features of GI lymphomas are heterogeneous, encompassing ulcers, erosions, polyps and so on. GI polyposis occurs in up to 10% of cases, including conditions such as multiple lymphomatous polyposis (MLP) and immunoproliferative small-intestinal disease (IPSID). MLP is a rare entity characterized by the presence of numerous GI polypoid lesions involving several digestive tract segments. Typical lymphoma presenting with MLP is mantle cell lymphoma (MCL). The differential diagnosis of GI MCL include adenomatous polyps, hereditary polyposis syndromes, colorectal carcinoma, GI lipomatosis, lymphoid nodular hyperplasia with hypogammaglobulinemia, among others. Diagnosis can usually be made based on endoscopic findings and histopathological analysis of their biopsy specimens. Immunohistochemistry for detection of the patognomonic cyclin D1 overexpression is mandatory. Systemic immunochemiotherapy is the treatment of choice. The management of MCL is challenging because it has the worst features of both high and low grade NHL - an aggressive clinical course but with a pattern of resistant and relapsing disease rendering it incurable to standard therapy. Therefore, the overall prognosis is poor.
We report an interesting case of MCL presented as MLP involving the entire intestine with remarkable endoscopic findings.
In conclusion, although GI lymphomatous polyposis is a rare disease, we emphasize that this entity should be included in the differential diagnosis of GI multiple polyposis. Furthermore, at present, the current therapeutic protocols cannot definitively cure the patients with GI tract MCL. Earlier diagnosis with further studies integrating novel agents are still required to determine the optimal treatment with less toxicity.