Epitheliotropic T-cell lymphoma
The disease is characterized by an indolent infiltration of neoplastic lymphocytes in the skin with a specific tropism for the epidermis and adnexal epithelium. Progression of disease may take years in some dogs.
Dogs often present with ulcerative stomatitis with no significant or only minor abnormalities on haematology and serum biochemistry panels. The skin shows varying degrees of erythematous, scaly and alopecic macules, patches or plaques. Lymphadenopathy is a rare accompanying presentation. no buccal lesions appear as multifocal flaccid bulla lesions filled with proteinaceous fluid that spontaneously rupture.
Diagnosis is usually based on presenting clinical signs and histopathological analysis of biopsied skin. Early-stage epitheliotropic T-cell lymphoma can clinically and histologically mimic a large range of inflammatory dermatoses and exclusion of other diseases is important before establishing a definitive diagnosis.
The histological appearance often takes on the forms of mycosis fungoides, pagetoid reticulosis or Sézary syndrome.
Immunohistochemistry is often employed to further characterize the tumor and distinguish it from erythema multiforme, and PCR assays are currently available for detection of T-cell receptor gamma (TCRgamma) rearrangements.
Buccal forms of this disease can progress rapidly and aggressively, leading to violent, uncontrollable pruritus, which may be disturbing for the owner.
The prognosis is considered to be poor, with survival times from few months to 2 years.
Dogs are usually euthanized in cases that progress to high-grade lymphoma or have poor quality of life.
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