Cutaneous lesions.

Although not a substitute for histologic examination, lumps, bumps, and lesions of the skin and subcutis readily lend themselves to cytologic examination via FNB, fine-needle nonaspiration biopsy, imprinting, or scraping of lesions. These techniques are used to obtain cells that can be examined by a clinical pathologist or cytologist to provide a diagnosis, decide a course of therapy, or offer a prognosis. Although histologic and cytologic examinations do not always agree, many times there is excellent correlation between the two disciplines. There are few patients with cutaneous lesions that would not benefit from cytologic examination of their lesion.     

Cutaneous drug eruptions

A drug-induced cause should be considered by the veterinarian when presented with any dermatosis and, in particular, those dermatoses that seem to have an underlying immunologic mechanism. A detailed history should be taken and a thorough dermatologic examination always performed. Biopsy submitted for histologic assessment can be a valuable aid to arriving at a diagnosis. Ultimately, response to withdrawal of the drug causing resolution of the dermatosis would confirm the diagnosis of a drug eruption.     

Cutaneous staphylococcosis in rabbits

An outbreak of cutaneous staphylococcosis caused high mortality among newborn and very young rabbits. The most typical lesions were exudative dermatitis in the youngest, subcutaneous abscesses in rabbits of all ages and mastitis in lactating does. Generalised staphylococcosis was a frequent secondary manifestation of the disease.     

Cutaneous histiocytosis in dogs

Multifocal cutaneous histiocytic lesions were recognized in 9 dogs. Clinically, the dogs had multiple erythematous plaques or nodules in the skin (1 to 5 cm diameter). Histologically, the lesions were comprised of dermal or pannicular infiltrates of large histiocytic cells, with varying numbers of other inflammatory cells intermixed. By electron microscopy, the cells resembled those of canine cutaneous histiocytoma. The lesions seemed to wax and wane and appeared in new sites, regardless of treatment. The dogs ranged in age from 2 to 13 years; 7 dogs were under 6 years of age. Both sexes and various breeds were represented. An infectious agent could not be identified.     

Cutaneous paecilomycosis in a cat

A cat was presented for a 2-year history of a recurrent, soft-tissue swelling of the left metacarpal region. The mass was excised and submitted for aerobic and anaerobic bacterial culture, fungal culture, and histopathological examination. Cultures revealed the organism Paecilomyces lilacinus, and histopathological examination showed a nodular mycotic granuloma. Itraconazole (10 mg/kg body weight, per os [PO], q 24 hours) was administered and continued for a total of 60 days, with a swelling of the upper lip occurring 3 months after the initial presentation. Subsequent surgical excisions and debridements along with treatment with itraconazole (20 mg/kg body weight, PO, q 24 hours) for a total of 4 months were curative.     

Cutaneous vasoproliferative lesions in goats

Abstract. In a retrospective survey of caprine neoplastic disease, eight masses were diagnosed as cutaneous vascular tumors. The typical clinical presentation was a solitary raised, bleeding mass. No predilection with regard to age, breed, sex, or anatomic location was found. Reevaluation of the microscopic features of the masses resulted in diagnoses of hamartoma (2), hemangioma (4), and hemangiosarcoma (2). An endothelial cell origin was confirmed in all seven tumors tested immunohistochemically for factor VIII-related antigen. Although rarely reported, goats display a range of cutaneous vascular growth abnormalities similar to those observed in other domestic animals.     

Cutaneous alternariosis in a cat

A 10-year-old male domestic shorthaired cat had a chronic, slowly enlarging subcutaneous mass on the right side of its nose. At the time of presentation, the nasal airflow was severely impeded on the affected side. The cat had been treated medically with various drugs. Oral itraconazole had been the most effective in reducing the size of the mass, but had caused hepatotoxicity and had to be withdrawn. The mass was finally removed surgically, and a diagnosis of granulomatous cellulitis caused by Alternaria alternata (phaeohyphomycosis) was established, based on histopathology and fungal isolation. There has been no recurrence of the lesion after 21 months and the cat remains clinically well at the time of writing. Subcutaneous phaeohyphomycosis caused by A alternata has not, to the authors' knowledge, been previously described in small domestic animals in the UK.     

Cutaneous blastomycosis in a horse

This report describes the case of a horse presented with cutaneous lesions caused by Blastomyces dermatitidis in the absence of signs of other organ involvement. Diagnosis was achieved through cytology, histopathology and culture. Surgical debulking associated with systemic therapy with oral fluconazole resulted in significant remission; however, recurrence occurred following presumed early cessation of treatment.     

Cutaneous histiocytoma in a goat

A cutaneous histiocytoma involving the scrotum was diagnosed in a 14-month-old French Alpine buck. A wedge biopsy was taken for histologic examination. The remaining tumor regressed spontaneously and had completely resolved within six months of initial observation.     

Cutaneous pythiosis in beef calves

Six Brahman and Brahman-cross calves less than or equal to 9 months old were examined because of ulcerative swellings of the fetlocks (5 calves) or numerous focal ulcerated cutaneous lesions (1 calf). Biopsies revealed focal cutaneous granulomas around regular, thick-walled branching hyphae, 4 to 9 micron in diameter. In all cases, portions of the hyphae were surrounded by granular encrustations, which ultrastructurally were composed of amorphous material comparable to antigen-antibody complexes. The protist Pythium sp was isolated from 2 calves.