Sterile nodular panniculitis with lung and lymph node involvement in a Siberian tiger (Panthera tigris altica)

HU, Shou-Ping; ZHANG, Zhuo; ZHANG, Jiao-Er; CAI, Xue-Hui; NAKAYAMA, Hiroyuki; HE, Xi-Jun

In this case, we were unable to identify any other etiologies besides the panniculitis after the tiger's death. After necropsy, we did not obtain biochemical data. Microbial examination was performed, and the bacterial, fungal, and mycobacterial cultures were negative. Reverse transcription-polymerase chain reaction was used to detect canine distemper virus and feline coronavirus RNA in the lymph node samples, and the results were negative. One of the histological features of the present case was variable inflammatory cell infiltration in the subcutaneous adipose tissue, including lymphocytes; plasma cells; and pleomorphic, lipid-laden macrophages. The lung was also infiltrated by the same types of inflammatory cells, and lipid infiltration was observed in the alveolar space. Although the mesenteric lymph nodes were also involved, the lung involvement likely led to the patient's death. Necrotic adipose and connective tissues, including the lung tissue, were followed by fibrosis. Lung involvement may cause a variety of clinical signs, including difficulty breathing, coughing, and the syndrome may not be recognized through respiratory signs.