Leishmania spp. in Perianal Adenoma in a Dog: A Case Report.

The coexistence of Leishmania and neoplasia is rarely reported in humans or animals. An 11-year-old intact male mixed-breed dog was presented with a well-demarcated perianal nodule. Cytologic and histopathologic examinations were consistent with the diagnosis of perianal gland adenoma with the presence of Leishmania amastigotes. The dog was considered to be in leishmaniasis stage C (clinically diseased) based on clinical signs, laboratory findings, and serological status. A novel finding in this case report was the presence of Leishmania within the perianal adenoma, probably resulting from an atypical dissemination of the parasites.

Comparison of two inoculation methods for Microsporum canis culture using the toothbrush sampling technique.

BACKGROUND: The fungal culture toothbrush method is a common method for obtaining material for fungal cultures to diagnose dermatophytosis. The optimal technique for inoculation onto the agar surface has not been studied. HYPOTHESIS/OBJECTIVES: To compare two inoculation techniques; the first involved pressing the toothbrush onto the plate surface (Procedure A) and the second involved pressing the toothbrush onto the agar, as well as transferring hairs and scales entrapped in the bristles. (Procedure B). The hypothesis was that transferring hairs onto the plate would increase the likelihood of obtaining positive cultures. ANIMALS: Twenty-six cattery-housed cats were sampled using the toothbrush technique. Two toothbrush samples were obtained from each cat. METHODS AND MATERIALS: The two toothbrush samples from each cat were randomized to Procedure A or B, and the investigator was blinded to inoculation technique. Cultures were performed on a medium specific for dermatophytes. The number of positive plates, and the presence and abundance of colonies of dermatophytes and contaminant moulds were compared between the two techniques. RESULTS: Twenty-one cats were culture-positive for Microsporum canis. Procedure A resulted in a significantly higher number (P < 0.01) of positive plates (20 of 21; 95%) compared with Procedure B (seven of 21; 33%). These results were due mainly to higher plate invasion by contaminant moulds, using Procedure B. CONCLUSIONS AND CLINICAL IMPORTANCE: Based upon the findings of this study, the optimum inoculation technique is to press toothbrush bristles onto agar plates to maximize growth of M. canis and minimize introduction of contaminant inoculation.

A retrospective histopathological, immunohistochemical and molecular study of the presence of Leishmania spp. in the skin of cats with head and neck ulcerative dermatitis.

BACKGROUND: Head and neck ulcers in cats can arise from allergic and nonallergic disorders, including feline leishmaniosis (FeL). It is important to rule out this aetiological agent in regions that are endemic for canine leishmaniosis, because the drugs used to treat immune-mediated disorders of cats can be contraindicated in the setting of infection. HYPOTHESIS/OBJECTIVES: The aim of this study was to evaluate the skin of cats with ulcerative dermatitis of the head or neck for evidence of Leishmania infection using combined immunohistochemistry (IHC) and Polymerase Chain Reaction (PCR). An IHC for tissue histiocytes was also utilized because leishmaniosis may provoke a histiocytic inflammatory response. ANIMALS: Twenty seven cats with head and/or neck ulcers. METHODS: Skin biopsy specimens were examined for the presence of Leishmania spp. by routine histopathological evaluation and IHC using a polyclonal anti-Leishmania antibody, and by quantitative PCR (qPCR). The ionized calcium-binding adapter molecule-1 (IBA-1) antibody was used to immunolocalize histiocytes. Selected history and clinical data were recorded. RESULTS: All specimens showed a superficial mid-perivascular mixed inflammatory infiltrate. The presence of histiocytes was confirmed in 23 of 27 cases with the IBA-1 antibody. Immunohistochemistry and qPCR techniques confirmed the absence of Leishmania in all cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Leishmania did not seem to play a role in the pathogenesis of feline ulcerative dermatitis of the head and neck in the subjects studied, despite a lifestyle potentially associated with infection. Histiocytic infiltration of tissue is not a specific marker for Leishmania infection in this population.

Loco-regional immune default: The immunocompromised district in human and comparative dermatology.

Lately, the innovative concept of an immunocompromised cutaneous district (ICD) has been introduced to explain why a previously injured cutaneous site may become in time a privileged location for the onset of opportunistic infections, tumors, and immune reactions. The injuring events capable of rendering a skin region a potential ICD are various, numerous, and most of the time identifiable by means of a careful clinical history. The reason that only a small minority of injured skin areas actually becomes ICDs, with subsequent opportunistic localization of a second and unrelated skin disorder, is presently unknown. The ICD is a conceptual entity that is not limited to human dermatology. It can also apply to veterinary medicine. Development of sarcomas at the injection site in cats after routine vaccination and, occasionally, administration of pharmaceutical products, as well as insertion of any foreign body, is a repeatedly documented event. Antigen load, persistent inflammation, and fibroblastic proliferation are thought to be important factors predisposing to the onset of fibrosarcoma in cats. Recently, it has been hypothesized that a local immunosuppression caused by inhalant glucocorticoids may have favored the development of regional demodicosis in cats. In our opinion, injection-site sarcomas and feline localized demodicosis can be considered examples of veterinary ICDs.

Fine needle aspiration of metastatic epithelioid angiosarcoma: a report of 2 cases.

BACKGROUND: Epithelioid angiosarcomas (EAs) are uncommon mesenchymal tumors occurring in the thyroid, deep-seated soft tissues, parenchymal organs and, more rarely, superficial soft tissues of the head and neck. Due to their cytologic and immunocytochemical presentation on fine needle aspiration cytology (FNAC) samples, these neoplasms may closely mimic a number of different tumors, potentially causing an erroneous cytopathologic diagnosis unless immunophenotypical markers of vascular differentiation are sought in the cellular material. CASES: A 68-year-old man with a 1-year history of total thyroidectomy for EA presented with a suspicious right neck node and underwent FNA. A 63-year-old woman with a history of recurring multiple scalp nodules diagnosed as EA ultimately developed small multiple, bilateral lymph nodes in the neck and underwent FNA. In both cases a cytopathologic diagnosis of metastatic EA was made. CONCLUSION: The cytopathologic diagnosis of EA is a challenge. Knowledge of the clinical history is of great help in diagnosing metastatic lesions. The cytopathologicpicture of metastases is a useful way for cytopathologists to gain confidence with presentaton of this rare entity in primary sites on FNAC samples. Cytopathologic hints of vascular differentiation should be sought in the cytopathologic material when a diagnosis of EA is entertained.

Canine mastocytoma: report of 8 cases diagnosed by fine needle cytology and clinicopathologic correlations.

BACKGROUND: Mast cell proliferations are commoner in dogs than in humans; mass forming lesions in the former are apt to fine needle sampling and the obtained cytopathological picture might be informing to enhance recognition of similar proliferations in humans. CASE: Clinical and cytopathologic data were collected from 8 cases of canine mastocytomas diagnosed by fine needle cytology. The cytopathologic presentation was correlated with the individual therapy performed and with the clinical stage. In all cases the cytopathological diagnosis was confirmed by histopathologic examination of the excised mass, by necropsy or by response to therapy. CONCLUSION: There are marked similarities between canine and human mastocytomas, despite possible differences in the clinical course of the disease in both species. Canine mastocytomas may hence be used as an animal model of a human disease and, as such, familiarity with their cytologic presentation may be useful for recognizing mast cell proliferations in humans.