Résumé
ABSTRACT 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.