Thymoma-associated Exfoliative Dermatitis in Cats

Abstract

Abstract. Five cases of exfoliative dermatitis in cats were presented from 1996 to 2002 in which a feline thymoma was found by postmortem or postsurgical examination. Besides abundant exfoliation of keratin squames and layers, the histologic picture of the skin revealed a similar pattern of interface dermatitis with predominantly CD3ϩ lymphocytes and fewer mast cells and plasma cells. In the epidermal basal layer a hydropic degeneration of keratinocytes was present. In all cases an infundibular lymphocytic mural folliculitis and absence of or drastic decrease in the number of sebaceous glands occurred. In addition to the so far described cell-poor type, we also found examples of a cell-rich skin lesion. Together with the clinical observation of generalized exfoliative dermatitis, the histologic pattern of this dermatitis was suggestive of an underlying thymoma. The pathogenesis of this skin disease in association with thymic neoplasia remains obscure, and our results contradict the hypothesis of production of autoantibodies that cross-react with epithelial antigens. The morphology of the thymomas and CD3 expression of the thymocytes varied and did not seem to have an impact on the dermal lesions.

Paraneoplastic exfoliative erythroderma in a cat with thymoma

“…Dyspneic bouts and/or coughing can be attributed to the space-occupying effect and/or secon dary pleural effusion (Moore and Ogilvie 2001); apparently, the latter condition did not develop in our cat. Exfoliative dermatitis, also appearing with the other clinical and/or paraneoplastic manifestations of thymoma, may be the sole presenting complaint (Bonnard and Dralez 1992, Scott et al 1995, Forstervan Hijfte et al 1997, Rottenberg et al 2004, Singh et al 2010, as it was the case in this cat. Typically, it is a progressive and non-pruritic dermatitis, the lesions of which start from the head and ear pinnae, to spread eventually all over the body (Scott et al 1995, Forstervan Hijfte et al 1997, Rottenberg et al 2004.…”

“…Exfoliative dermatitis, also appearing with the other clinical and/or paraneoplastic manifestations of thymoma, may be the sole presenting complaint (Bonnard and Dralez 1992, Scott et al 1995, Forstervan Hijfte et al 1997, Rottenberg et al 2004, Singh et al 2010, as it was the case in this cat. Typically, it is a progressive and non-pruritic dermatitis, the lesions of which start from the head and ear pinnae, to spread eventually all over the body (Scott et al 1995, Forstervan Hijfte et al 1997, Rottenberg et al 2004. Similar to this case, a heavy accumulation of scales and crusts is a common occurrence (Scott et al 1995).…”

“…Exfoliative dermatitis in the cat has mainly been associated with thymoma (Rottenberg et al 2004). However, of as many as 100 feline thymomas retrieved by the authors in a literature review, only 16 had exfoliative dermatitis (Loveday 1959, Dubielzig andJOURNAL OF THE HELLENIC VETERINARY MEDICAL SOCIETY 2011,62(3) ΠΕΡΙΟΔΙΚΟ ΤΗΣ ΕΛΛΗΝΙΚΗΣ ΚΤΗΝΙΑΤΡΙΚΗΣ ΕΤΑΙΡΕΙΑΣ 2011,62(3) DeLaney 1980, Willard et al 1980, Carpenter and Holzworth 1982, Bonnard and Dralez 1992, Gores et al 1994, Scott et al 1995, Forster-van Hijfte et al 1997, Day 1997, Godfrey 1999, Riviere and Olivry 1999, Smith et al 2001, Smits and Reid 2003, Rottenberg et al 2004, Lara-Garcia et al 2008, Fidel et al 2008, Spadavecchia and Jaggy 2008, Zitz et al 2008, Singh et al 2010.…”

“…However, of as many as 100 feline thymomas retrieved by the authors in a literature review, only 16 had exfoliative dermatitis (Loveday 1959, Dubielzig andJOURNAL OF THE HELLENIC VETERINARY MEDICAL SOCIETY 2011,62(3) ΠΕΡΙΟΔΙΚΟ ΤΗΣ ΕΛΛΗΝΙΚΗΣ ΚΤΗΝΙΑΤΡΙΚΗΣ ΕΤΑΙΡΕΙΑΣ 2011,62(3) DeLaney 1980, Willard et al 1980, Carpenter and Holzworth 1982, Bonnard and Dralez 1992, Gores et al 1994, Scott et al 1995, Forster-van Hijfte et al 1997, Day 1997, Godfrey 1999, Riviere and Olivry 1999, Smith et al 2001, Smits and Reid 2003, Rottenberg et al 2004, Lara-Garcia et al 2008, Fidel et al 2008, Spadavecchia and Jaggy 2008, Zitz et al 2008, Singh et al 2010. Apart from exfoliative dermatitis, myasthe nia gravis is a well-known paraneoplastic condition in cats with thymoma, appearing alone or in combination with the former dermatitis (Scott-Moncrieff et al 1990, Singh et al 2010); polymyositis and granulocytopenia may, also, develop but far less commonly (Moore andOgilvie 2001, Fidel et al 2008).…”

First Case of Degenerative Mucinotic Mural Folliculitis in Brazil

“…Chest radiography showed no mass or changes suggestive of thymoma, which is a differential diagnosis for non-pruritic exfoliative dermatitis, with histopathological presentation of symptoms of lymphocytic mural folliculitis [8].…”