Peritoneal Lymphomatosis Mimicking Peritoneal Carcinomatosis from Ovarian Malignancy on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

High-grade B-cell lymphoma, not otherwise specified, presenting as primary peritoneal lymphomatosis and successfully treated with dose-adjusted EPOCH-R

Peritoneal lymphomatosis (PL) is a rare lymphoma-associated condition defined as the dissemination of lymphoma cells in the peritoneum. An 82-year-old man presented with abdominal pain, heartburn, and high fever. Radiological findings, including positron emission tomography-computed tomography (PET-CT), and gastrointestinal fiberscopy, showed diffuse thickening of the peritoneum, omentum, and mesentery; however, no lymphadenopathy, hepatosplenomegaly, or gastrointestinal lesions were observed. Under suspicion of peritonitis carcinomatosa of unknown origin, exploratory laparoscopy was performed that revealed multiple white nodules and masses on the surfaces of the peritoneum, mesentery, and intestinal serosa. The histopathological and cytogenetic findings of the peritoneum revealed high-grade B-cell lymphoma, not otherwise specified, and a gain of MYC by fluorescence in-situ hybridization. The patient was treated with two cycles of R-CHOP therapy, followed by six cycles of dose-adjusted EPOCH-R therapy, and a complete metabolic response was confirmed by PET-CT. Since there are no specific radiological findings to confirm the diagnosis of PL, a histopathological diagnosis is usually required. Most PL exhibit an aggressive lymphoma phenotype and can be cured by appropriate chemotherapy. Therefore, early diagnosis and treatment are desirable.

Diffuse Large B-cell Lymphoma Presenting as Peritoneal Lymphomatosis: A Case Report and Literature Review

Peritoneal lymphomatosis (PL) is a rare presentation of malignant lymphoma cases, many of which are diagnosed as diffuse large B-cell lymphoma (DLBCL) and characterized by aggressive clinical courses. We herein report a 63-year-old woman presenting with the rapid development of abdominal distention due to bulky peritoneal tumors. The pathological evaluation of a needle biopsy sample, combined with flow cytometry, yielded the diagnosis of DLBCL. Prompt chemotherapeutic intervention resulted in favorable disease control and sustained complete remission. It is necessary to diagnose cases of DLBCL presenting as PL early to ensure prompt treatment and prevent mortality.

High-grade B-cell lymphoma masquerading as peritoneal lymphomatosis

Peritoneal lymphomatosis represents a rare presentation of any type of non-Hodgkin's lymphoma, with relatively few cases reported in the literature. We present here the case of a 61-year-old man who originally presented with increased abdominal distention associated with shortness of breath and diaphoresis who was found to have evidence of peritoneal carcinomatosis on CT scan. Biopsy confirmed diffuse large B-cell lymphoma, and the working diagnosis was subsequently modified to peritoneal lymphomatosis. The patient was treated with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) therapy with initially good response. His course was complicated by tumour lysis syndrome. We review the limited literature discussing peritoneal lymphomatosis and discuss the importance of facilitating rapid and efficacious treatment.