Tumors composed of discrete round cells with large eosinophilic granules in their cytoplasm were observed in four cats. These cats were presented with severe gastrointestinal signs, including anorexia, vomiting, and diarrhea. The exploratory laparotomy in two cats and necropsy in the other two revealed thickening and perforation of the intestinal walls, enlargement of the mesenteric, ileocolic, and/or colic lymph nodes, and splenomegaly. Histologically, there was severe and disseminated infiltration of the tumor cells in the affected organs. In the two cats necropsied, the spleen and the jejunal mucosa appeared to be the primary organs involved. The tumor cells of all the cats showed the pore-forming protein (perforin)-like immunoreactivity unique to the cytotoxic lymphocytes but failed to show histamine immunoreactivity. These results indicate that the tumor cells were derived from large granular lymphocytes and that perforinlike immunoreactivity may be a useful marker for histologic diagnosis of feline large granular lymphoma.

ABSTRACT. Of the various classification systems for non-Hodgkin's lymphoma, the updated Kiel classification is valuable for veterinary practice, because of its utility to classify the subtypes not only by histopathology but also by cytomorphology. However, there are only a few reports of small number of feline lymphomas to apply the updated Kiel classification. In this study, immunogical subtypes and morphology of 76 feline lymphomas were evaluated and classified into subtypes of the updated Kiel classification. Of the cases, 49% were T-cell lymphoma, 25% were B-cell lymphoma and 26% were undetermined immunological subtype. Based on the updated Kiel classification, most subtypes were identified also in feline lymphomas as in dogs and humans. Globule leukocyte lymphoma was specific for cats and relatively common in feline alimentary lymphomas. Of the present cases, 64% were high-grade subtypes, whereas 36% were low-grade subtypes. The present study indicated that feline lymphomas could be morphologically classified by the modified updated Kiel classification.

We report a dog with dystrophic epidermolysis bullosa. This 4-year-old female Akita Inu, a species of Canis familiaris var. japonicus Temminck, had a 3-year-history of ulcers and scars over the pressure areas on the limbs, and dystrophic nails, since the age of 1 year, which corresponds to early adulthood in humans. Electron microscopy of a blister revealed separation beneath the lamina densa, and a reduction in the number of anchoring fibrils. The NC-1 domain of type VII collagen was positively stained with monoclonal antibody LH7.2 at the basement membrane zone. These findings indicate that humans and dogs have a similar response to antibody LH7.2, which may aid the development of an animal model for this disease.

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ABSTRACT. Multiple, pigmented, verrucous, cutaneous lesions in a 2-year-old female cat were pathologically examined. The lesions were linearly arranged on the right side of the body, and had developed along with moderate pruritus since infancy. Histologically, prominent exophytic, papillomatous outgrowths of the epidermis and acanthosis with intense ortho and parakeratotic hyperkeratosis were characteristic of the lesions. Dermal inflammation with mononuclear cells, neutrophils, and eosinophils was also noted. Inclusion bodies, cellular degeneration, and intranuclear viral particles suggesting papillomavirus infection in the keratinocytes were not observed. Papillomavirus antigen and DNA were not detected in the lesions by immunohistochemistry and polymerase chain reaction, respectively. In accordance with these clinical and histopathological features, the cutaneous lesions of the present cat were diagnosed as epidermal nevi, which were consistent with human inflammatory linear verrucous epidermal nevi. Cutaneous papilloma, or verrucous lesions, which are rarely seen in cats, may be caused by viral infections, developmental anomalies, or traumatic stimuli of the skin [5]. The time of onset, gross appearance, and pathological features of the skin lesions are important for differential diagnosis. Two cases of feline cutaneous papilloma associated with papillomavirus (PV) infection have been reported [3,9], although cases of congenital origin have not been described. We report a young cat with multiple, characteristic, linearly arranged, cutaneous, verrucous lesions that had developed during infancy. Pathological features of the lesions did not accord with PV infection, and rather similar to those of inflammatory linear verrucous epidermal nevus (ILVEN), a variant of epidermal nevi in humans [1,7].A 2-year-old female domestic short-haired cat developed multiple, verrucous lesions with erythematous margins arranged in a linear pattern on the right side of the body (Fig. 1). The lesions ranged from 5 mm to 30 mm in diameter and were moderately pigmented, although their surfaces were often light brown. According to the owner, these cutaneous lesions along with moderate pruritus had been observed since infancy. The cat had been reported to present with right-sided ataxia and intention tremor.All masses were surgically removed and tissue samples were fixed in 10% neutral-buffered formalin and embedded in paraffin wax. The sections (4 µm) were cut and stained with hematoxylin and eosin (HE). A standard immunoperoxidase technique was used for the immunohistochemical detection of the PV antigen. The paraffin sections were treated with rabbit polyclonal anti-bovine papillomavirus (BPV-1) antibody (DakoCytomation, Carpinteria, CA, U.S.A.). Before incubation with the primary antibody, the deparaffinized sections were treated with 0.1% trypsin for 1 hr at 37°C. Peroxidase-conjugated anti-rabbit IgG [Histofine Simple Stain MAX-PO (R); Nichirei, Tokyo, Japan] was used as the secondary antibody. The reaction products were visual...