A 4-year-old, British short hair cat, living in Hong Kong, was presented with fever, chronic intermittent signs of diarrhoea and with a colonic intramural mass found at laparoscopy. Cytological evaluation of the mass showed a pyogranulomatous and fibrotic inflammatory process.
Histopathology of a section of the colonic mass confirmed this process and additionally revealed the presence of numerous macrophages containing intracytoplasmic round organisms (Figs 1 and 2). The organisms stained positively with Gomori’s methenamine silver stain (Fig. 3).
Fig. 1. Section of colon with submucosal granulomatous and fibrotic inflammatory process centred on lymphoid aggregates.
Fig. 2. Macrophages with numerous intracytoplasmic round organisms, 2-4mm in diameter.
1.The histopathology is consistent with what disease?
2.What technique(s) will enable definitive diagnosis of the disease?
c.Histopathology and special stains/IHC
Case 2 is written by Dr. Ana R. Resendes