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

The pathogenetic mechanism of SNP has not yet been fully established. Thus far, the eventual pathological characteristics are similar irrespective of the underlying trigger. The histopathological findings in the present case are similar to previously reported cases [12] . As an idiopathic disorder, SNP may occur as a primary disease or may be associated with any number of other illnesses [7, 16, 17, 19] . A wide variety of causes can induce SNP, including trauma, infection, foreign bodies, vitamin E or other nutritional deficiency, drug eruption, insect bite, and neoplasia [16, 17] . It has also been suggested that panniculitis can be classified based on the presence or absence of systemic symptoms. Panniculitis without systemic disease results from trauma or cold; panniculitis with systemic disease is typically due to collagen vascular disease, pancreatic disease, or lymphoproliferative disorders [9] . Alpha 1-antitrypsin deficiency is also a major cause of panniculitis in humans [20] . In the present case, no physical or chemical agents were evident in the clinical history. We did not find any evidence of trauma, and infection was excluded based on the laboratory test results. Nutritional (vitamin E) deficiency, insect bite, and autoimmune disorder, alone or in combination appear to be the leading causes of SNP. Notably, a previous report demonstrated that subcutaneous injection of the rabies vaccine was associated with focal necrotizing granulomatous panniculitis in cats and dogs [8] ; however, the present case was not vaccinated, which excludes this particular etiology.