Peer-reviewed veterinary case report
Inflammatory pseudotumor on a cat's paw with skin mycobacteria
By Miller, M A et al.·Published in Veterinary pathology·1999·University of Missouri, United States·View original on PubMed →
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Original publication title: Inflammatory pseudotumor in a cat with cutaneous mycobacteriosis.
- Species:
- cat
Plain-English summary
A 5-year-old male domestic Shorthair cat was brought in with an ulcerated mass on its left hind paw that had developed painful openings. Despite attempts to treat the condition with antibiotics, the mass was found to be caused by a rare skin infection called cutaneous mycobacteriosis, specifically from Mycobacterium avium. Unfortunately, the cat did not respond to treatment and was euthanized due to the severity of the infection. This case highlights how mycobacteriosis can mimic other types of tumors in cats, making diagnosis challenging.
People also search for: cat ulcerated paw mass · mycobacteriosis in cats · cat skin infection treatment
Abstract
A 5-year-old, castrated male, domestic Shorthair Cat had an ulcerated mass with fistulous tracts on the left hind paw. Homogeneous tan tissue diffusely infiltrated the dermis and subcutis of the paw and extended proximally so that, short of amputation, complete excision was not feasible. Biopsy specimens consisted of granulation tissue with marked proliferation of spindle cells. Neutrophils and histiocytic cells were scattered among the spindle cells. The histiocytic cells had abundant foamy or vacuolated cytoplasm, but features of granulomatous inflammation, such as epithelioid macrophages or granuloma formation, were not observed. The initial impression was inflammatory granulation tissue, but the degree of fibroplasia prompted inclusion of fibrosarcoma in the differential diagnosis. Cutaneous mycobacteriosis was diagnosed when numerous acid-fast bacteria were identified with Kinyoun's stain; Mycobacterium avium was subsequently cultured. The cat was euthanatized because of lack of response to enrofloxacin therapy. At necropsy, lesions were localized to the hind limb. Not only is mycobacteriosis an uncommon cause of cutaneous masses in cats, but this case was unusual because of the lack of granuloma formation and the similarity of the mass to a spindle cell tumor.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/10098646/