A Case of Primary Ileocecal Lymphoma

Primary lymphoma in gastrointestinal tract is not very common. Ileocecal region is the commonest site for primary lymphoma and diffuse large B cell lymphoma (DLBCL) is the most prevalent subtype. The clinical presentation in this condition is pain in right lower quadrant region and this can very confusing since many diseases can also cause this problem like infection and inflammatory disease. In this paper, we report a case of primary lymphoma subtype DLBCL in ileocecal region that come to emergency department with ileus obstruction. Abdominal computerized tomography (CT) scan and colonoscopy revealed tumour in ileocecal region ascendens colon. Hemicolectomy was performed and the specimen was sent to pathology which revealed non-Hodgkin lymphoma with subtype DLBCL CD20 (+). The patient had undergone of Rituximab, Cyclophosphamide, Doxorubicine, Vincristin, and Prednison (RCHOP) chemotherapy regimen and had complete remission.


INTRODUCTION
Gastrointestonal tract is the most common place for extranodal metastasis by lymphoma that account 5-20% from all cases. 1 But primary gastrointestinal lymphoma, precisely small intestine is very rare that accounts about less than 2% of all gastrointestinal malignancies. From the small intestine lymphoma accounts 20-30% of all small intestine neoplasm, which ileocecal is the most common site (60-65%). 2 From primary intestinal Lymphoma B-cell Lymphoma is more frequent than T-Cell, with DLBCL is the most common subtype.
DLBCL ileosekal may have presenting symptoms such as abdominal pain, weight loss, ileus obstruction, or intussuception. 3,4,5 There are many diseases affecting ileocecal region such as malignant tumour, inflammatory disease, infectious disease, and miscellaneous condition. 6 RCHOP chemotherapy is the first line treatment of DLBCL and consists of Rituximab combination with Cyclophosphamide, Doxorubicine, Vincristin, and Prednison. The response rate of treatment of DLBCL with RCHOP is good. 4

CASE ILLUSTRATION
A 61 year old male with chief complaint pain in right illiac fossa come to emergency department of three months duration with a sudden increase in severity of pain.The pain started in epigastric then radiating to right illiac fossa. He had history of weight loss 20 kg in 3 months, decrease appetite, no night sweat. Physical examination revealed abdominal bloating and mass in right lower quadrant region. His laboratory examination revealed normochromic normocytic anemua, leucocytosis with high level serum lactic dehydrogenase(915 U/L). CT scan of the abdomen (Figure 1) revealed calcified mass in the colon region cecum with peripancreatic and left paraaortic lymphadenopathy, while colonoscopy ( Figure 2) revealed tumour in colon ileocecal region.
A right hemicolectomy was performed and the specimens of the tumour were sent to pathology. A histology diagnosis Non Hodgkin Lymphoma was made then immunohistochemistry result was positive for CD 20, CD 10, Ki-67 confirming the diagnosis of diffuse large B-cell lymphoma (DLBCL) with germinal center B-cell like subtype.    The patient then undergone chemoterapy with R-CHOP regiment 8 cycles and now had complete remission. Figure 3 and 4 below showed the abdominal PET CT and CT scan in abdominal region after chemotherapy and 6 months following the last RCHOP chemotherapy.

DISCUSSION
Lymphoma in small intestine usually have presenting symptoms such as abdominal pain, nausea, vomitting, weight loss, abdominal mass, obstructive symptoms, intussuception, perforation, and diarrhea with commonest pathological subtypes DLBCL. 3,4,5 Ileocecal region is relative short segment in gastrointestinal tract that have various component that close one to another. Because of this structure the diagnosis of pain in right illiac fossa must be made considering many condition such as malignant tumour, inflammatory disease, infectious disease, and miscellaneous condition. 6 Table 1 below shown many condition that must be considered before made diagnostic related to pain in right illiac fossa.
Serum lactic dehyrogenase (LDH) is usually elevated at the time of the diagnosis of aggresive NHL. The high activity of LDH at the time of diagnosis reflects increased tumor bulk. 7 Based on histology examination, DLBCL usually composed of intermediate large cells, which shows B-cell lineage with expression of pan B-cell antigens (CD 19, CD 20, CD 22, CD79A, and PAX5/BSAP) and is less commonly positive for germinal centre cell markers (CD 10 and BCL 6). 8 We performed Computed Tomography (CT) scan to delineate the location of the tumor and it is now recommended as the gold standard for staging DBCL patients because more sensitivity for nodal and extranodal site. 9 Tumor resection is the main treatment for primary gastrointestinal lymphoma because it also provide data to see the histology, staging, and extension for prognosis. 10 In study by Kim SJ et al in DLBCL patient that had surgery have better overall survival than patient who did not. 11 While the recommended chemotherapy for DLBCL in patient 60-80 years old is R-CHOP (Rituximab, Cyclophosmamide, Doxorubicin, Vincristine, Prednisone) 8 cycles given every 21 days. 12 Complete response was achieved in 76% patients with R-CHOP regiment compared to CHOP with 63%, and disease progression were lower in R-CHOP regiment (9%) than in CHOP (22%) in study by Coffier et al. 13 Primary Lymphoma that involved ileocecal region usually has better survival rates than in small and large intestine. 14 In this case hemicolectomy was done as the primary treatment, and then chemotherapy RCHOP definitely administered to the patient.