High-grade B-cell lymphoma masquerading as peritoneal lymphomatosis

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.

Non-Hodgkin's Lymphoma Presenting as Isolated Peritoneal Lymphomatosis: A Case Report and Literature Review

Peritoneal lymphomatosis is extremely rare and associated with poor prognosis. Most practitioners only pay more attention to peritoneal carcinomatosis. However, peritoneal lymphomatosis can be neglected and misdiagnosed. We report a teenager with 10 days of abdominal distension and pain accompanied by computed tomography scan suggesting diffuse thickening of the peritoneum and omentum and abdominopelvic effusion. Tuberculous peritonitis and peritoneal carcinomatosis were initially suspected. However, it was finally confirmed as non-Hodgkin’s B-cell lymphoma by omentum biopsies. He achieved complete remission after chemotherapy and autologous stem cell transplantation. But unfortunately, he suffered a relapse and died 10 months after diagnosis. Following a review of the literature, it can be concluded that the discovery of lymphomatosis in peritoneum is a rare finding. Lymphoma should be considered in the differential diagnosis of unexplained peritoneal thickening on computed tomography, and this case emphasizes the importance of early pathological diagnosis to make sure that the right treatment can be started opportunely.

Peritoneal lymphomatosis. A case report

Introduction

Involvement of the peritoneum occurs very rarely and is exceptional as an exclusive extranodal presentation of lymphomas. In most cases lymphomas associated with this rare entity are high-grade ones. PL secondary to high-grade nodal lymphoma is more frequent than primary peritoneal lymphoma, and there are only a few cases of the latter described in the literature.

Description of the case

We present the case of a patient with constitutional syndrome and imaging findings suggestive of peritoneal carcinomatosis who was finally diagnosed with a Diffuse Large B-cell Lymphoma (DLBCL) by an ultrasound-guided core needle biopsy (CNB) of peritoneum. The patient received one polychemotherapy cycle; however tumor lysis syndrome occurred with death of the patient in the following days.

This case tries to show the existence of a PL without other radiological findings of lymphoma, a fact that is very exceptionally described in the literature.

Discussion

The differential diagnosis between PL and others peritoneum diseases such as peritoneal carcinomatosis, malignant primary peritoneal mesotheliomas, tuberculous peritonitis, sarcomatosis, diffuse peritoneal leiomyomatosis or benign splenosis, constitutes a major problem in imaging techniques.

An exhaustive analysis of the radiological characteristics as well as a clinical-analytical context allows the differential diagnosis against peritoneal carcinomatosis and the rest of the entities previously referred although the final diagnosis will always be a biopsy.

Conclusion

PL usually manifests as an aggressive histological subtype of high-grade lymphomas leading to a rapid progression and deterioration of the patient. It is crucial for the radiologist and the clinician to be aware of this rare entity providing the earliest possible diagnosis and optimal treatment to prolong the patient's life.