Peritoneal lymphomatosis: CT and PET/CT findings and how to differentiate between carcinomatosis and sarcomatosis

Abstract

Peritoneal lymphomatosis is a rare manifestation of lymphoma, seen most frequently with non-Hodgkin lymphoma, and it is important to be familiar with this condition, because early diagnosis directly affects the management of patients. This review illustrates the spectrum of imaging findings in peritoneal lymphomatosis, highlighting the use of positron emission tomography/computed tomography, showing common and uncommon subtypes of lymphoma associated with this entity, and how to differentiate it from peritoneal carcinomatosis and peritoneal sarcomatosis.

Sonographic features of peritoneal lymphomatosis in 4 cats

“…Ultrasound is the mainstay for diagnosing intestinal diseases in dogs and cats, whereas human medicine relies heavily on computed tomography (CT) . The differences between the CT appearance of the 3 peritoneal secondary malignancies in humans has been described and includes multiple small nodules with local lymphadenopathy in carcinomatosis, bulky heterogeneous masses in sarcomatosis and bulky homogenous masses with diffuse lymphadenopathy in lymphomatosis . Additionally, carcinomatosis was generally associated with larger quantities of free abdominal fluid than lymphomatosis .…”

“…In human medicine seeding through the peritoneal folds and ligaments from alimentary lymphoma or lymphatic dissemination have been suggested . Primary neoplasia arising from the peritoneum is rare as compared to secondary neoplasia, which arises from the transcoelomic spread of a malignancy originating from the epithelial (carcinomatosis), mesenchymal (sarcomatosis), or hematopoietic (lymphomatosis) cell lines …”

“…2 Primary neoplasia arising from the peritoneum is rare as compared to secondary neoplasia, which arises from the transcoelomic spread of a malignancy originating from the epithelial (carcinomatosis), mesenchymal (sarcomatosis), or hematopoietic (lymphomatosis) cell lines. 3 To the authors' knowledge, 3 cases of peritoneal lymphomatosis in cats have been reported and the sonographic characteristics are yet to be described. 4,5 The purpose of this article is to describe the Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; CT, computed tomography; ECVDI, European college of veterinary diagnostic imaging; FeLV, feline leukemia virus; FIP, feline infectious peritonitis; FIV, feline immunodeficiency virus; HGAL, high grade alimentary lymphoma; IGAL, intermediate grade alimentary lymphoma; LGAL, low grade alimentary lymphoma.…”

Peritoneal carcinomatosis or something else?

“…Extranodal lymphoma refers to the lymphomatous involvement of sites other than the lymphoid tissue of the lymph nodes, the tonsils, thymus and the Waldeyer lymphatic ring. It is more common in non‐Hodgkin’s lymphomas and is associated in up to 40% of cases of non‐Hodgkin’s lymphoma . Extranodal lymphoma occurs most commonly in the gastrointestinal tract but may involve any organ or system.…”

“…The treatment and prognosis of these clinical entities may differ dramatically. Radiological features suggestive of PL that may be identifiable on CT imaging of the abdomen include more frequent lymphadenopathy in a nodular pattern and splenomegaly . An accurate diagnosis however cannot be made on the imaging findings alone and it is impossible to differentiate between peritoneal carcinomatosis and PL radiologically …”