Lymphosarcoma associated with Heterobilharzia americana infection in a dog

Abstract

Abstract. Hepatic T-cell lymphosarcoma with involvement of regional lymph nodes and concurrent schistosomiasis were diagnosed in an 11-year-old male neutered mixed-breed dog with a history of chronic weight loss, inappetence, vomiting, and diarrhea. Trematode ova present in the hepatic parenchyma and mesenteric node were surrounded by sheets of neoplastic lymphocytes while those in the intestinal wall were surrounded by large numbers of non-neoplastic lymphocytes. Immunohistochemistry revealed that both the neoplastic and hyperplastic populations were T lymphocytes. The ova were identified by fecal saline sedimentation as Heterobilharzia spp., and fecal ova shedding resolved after praziquantel anthelmintic treatment. The lymphoma progressed despite chemotherapy, and the dog was euthanized after developing neurologic signs and a necropsy was performed. A monomorphic population of neoplastic T cells expanded and replaced normal architecture in the liver and spleen, surrounded nerve roots within the cauda equina, and infiltrated the meninges of the brain. The presence of schistosome ova embedded within neoplastic T-cell infiltrates suggests that, as previously reported in human schistosomiasis, heterobilharziasis may be associated with neoplasia.

Geographical differences in survival of dogs with non‐Hodgkin lymphoma treated with aCHOPbased chemotherapy protocol

“…A case report of an 11‐year‐old dog with concurrent T‐cell lymphoma and Heterobilharzia suggested that, as in humans, schistosomiasis might contribute to the development of lymphoma. This aggressive lymphoma was refractory to treatment and the disease progressed rapidly . There is also an increase in the incidence of atopic conditions among pet populations in the South, again because of the warmer climates.…”

RNAscope: a novel method for the detection of Heterobilharzia americana ova in canine liver

“…2,4 Aberrant migration and entrapment of ova results in local tissue injury. 2,4,16 Current detection methods include fecal saline sedimentation (FSS), molecular techniques (PCR, quantitative realtime PCR [qPCR]) using DNA or RNA isolated from stool or tissue, and identification of ova in H&E-stained, formalinfixed, paraffin-embedded (FFPE) tissue. 3,8,12,15 FSS is the most common method used by general practices to screen for Heterobilharzia ova, but it lacks sensitivity (50%).…”