Canine epitheliotropic T-cell lymphoma

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Epitheliotropic T-cell lymphoma on the cheek of a dog

The epitheliotropic T-cell lymphoma of the dog is a lymphoma of the skin as a mucocutaneous lesion in domestic dogs . The appearance is very variable, which is why the diagnosis can only be made on the basis of a biopsy . Chemotherapy drugs are mainly used for treatment , and the prognosis is poor.

Clinical picture and diagnosis

The clinical picture of this tumor disease is very variable and is divided into four forms:

  1. The exfoliative erythroderma is by extensive skin redness ( erythema ), dandruff , depigmentation , hair loss and itching in the head and torso. Lymph node swelling can occur. Exfoliative erythroderma usually changes into the third form. In terms of differential diagnosis, sarcoptic mange , Cheyletiellosis , atopic dermatitis , food allergy , vasculitis and cornification disorders are to be distinguished, and leishmaniasis in dogs living in southern Europe .
  2. Mucocutaneous lesions , i.e. changes in the skin- mucous membrane transitions, occur in the form of reddening, depigmentation, hair loss, erosions and ulcers . This mainly affects the face and the changes are symmetrical on both sides. The main distinctions here are lupus erythematosus , pemphigus foliaceus , pemphigus vulgaris and erythema exudativum multiforme .
  3. Plaques and nodules can appear either individually or in groups. They are reddened, encrusted and prone to erosion and ulceration, which can combine to form larger structures (coalescence). In the advanced stage, the regional lymph nodes are involved. Here, other tumors, skin infections such as leishmaniasis, kerion , mycobacteriosis , panniculitis and pyogranulomas must be clarified using differential diagnosis .
  4. Ulcers of the oral mucosa can occur on the tongue , on the roof of the mouth or in the area of ​​the gums . Chronic gingivitis of other origins must be differentiated here.

The diagnosis is made based on skin biopsies . Histopathologically, an infiltration of the skin with neoplastic T lymphocytes can be demonstrated. In contrast to mycosis fungoides in humans, in the majority of cases the cells are CD4 (-) and CD8 (+).

treatment

Local treatment, as in humans, is not established in dogs, as the diagnosis is usually only made at an advanced stage. Peroral treatment with lomustine has been tried and tested best . In one study, 83% of dogs responded to this active ingredient and 26% achieved complete remission .

A chemotherapy with doxorubicin , asparaginase or protocols with cyclophosphamide , vincristine and prednisolone can be tried. Older studies were also able to achieve remission with the administration of isotretinoin and polyunsaturated fatty acids . Individual nodes can also be removed surgically.

The prognosis is unfavorable. The survival time is two weeks to two years. The earlier the diagnosis and therapy started, the longer the survival time.

literature

  • TL Gross et al .: Skin diseases of the dog and cat. Clinical and histopathologic diagnosis. Blackwell Publ. Oxford, 2nd edition 2005.
  • Katrin Timm and Claudia S. Nett-Mettler: Pruritus in dogs (Part 2) - Infectious and neoplastic causes. In: Kleintierpraxis , Volume 60, 2016, Issue 6, pp. 311–332.

Individual evidence

  1. ↑ J. Fontaine, C. Bovens, p Bettenay, RS Mueller: Canine cutaneous epitheliotropic T-cell lymphoma: a review. In: Veterinary and comparative oncology. Volume 7, Number 1, March 2009, pp. 1-14, doi : 10.1111 / j.1476-5829.2008.00176.x , PMID 19222826 (review).
  2. ↑ RE Risbon, LP de Lorimier, K. Skorupski, KE Burgess, PJ Bergman, J. Carreras, K. Hahn, A. Leblanc, M. Turek, J. Impellizeri, R. Fred, JW Wojcieszyn, K. Drobatz, CA Clifford: Response of canine cutaneous epitheliotropic lymphoma to lomustine (CCNU): a retrospective study of 46 cases (1999-2004). In: Journal of veterinary internal medicine. Volume 20, Number 6, 2006 Nov-Dec, pp. 1389-1397, PMID 17186855 .