CONCOMITANCE OF A CUTANEOUS MYXOMA AND TRICHOEPITHELIOMA IN A RABBIT (ORYCTOLAGUS CUNICULUS)

Luis Jhordy Alfaro Quillas; Hikary Farfán Coronado; JOSINA DA CONCEIÇÃO VASCO BERNARDO; Consuelo Rojas Melgar; Daniel Guimarães Ubiali

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Título do Trabalho

CONCOMITANCE OF A CUTANEOUS MYXOMA AND TRICHOEPITHELIOMA IN A RABBIT (ORYCTOLAGUS CUNICULUS)

Autores

Luis Jhordy Alfaro Quillas
Hikary Farfán Coronado
JOSINA DA CONCEIÇÃO VASCO BERNARDO
Consuelo Rojas Melgar
Daniel Guimarães Ubiali

Modalidade

Resumo Simples

Área temática

Outras áreas temáticas

Data de Publicação

22/05/2026

País da Publicação

Brasil

Idioma da Publicação

pt-BR

Página do Trabalho

https://www.even3.com.br/anais/x-simposio-internacional-ciencias-veterinarias/1432142-concomitance-of-a-cutaneous-myxoma-and-trichoepithelioma-in-a-rabbit-(oryctolagus-cuniculus)

ISBN

978-65-272-2456-3

Palavras-Chave

Cutaneous myxoma, trichoepithelioma, rabbit (Oryctolagus cuniculus), skin neoplasms

Resumo

Cutaneous myxoma in rabbits is caused by the myxoma virus (MV), a poxvirus that induces the disease known as myxomatosis, which is associated with immunosuppression and characterized by the formation of tumor-like nodules (myxomas) in various parts of the body. On the other hand, trichoepithelioma is a relatively common skin neoplasm in rabbits. These tumors are characterized by an encapsulated and well-demarcated multilobular cellular proliferation with differentiation in the three segments of the hair follicle. This work aims to describe pathological characteristics of the development of a cutaneous myxoma and a trichoepithelioma in a rabbit (Oryctolagus cuniculus), highlighting the simultaneous presence of two types of neoplasms in the same tumor mass. A specimen of Oryctolagus cuniculus, a 6-year-old uncastrated male of the Rex breed, black and white in color, with a history of rapid growth of a mass in the craniofrontal region without significant clinical signs, was subjected to surgery for tumor removal. The entire tumor was collected with a surgical margin, fixed in 10% formalin, and sent to the Pathology Department for histology. Microscopically, the sections stained with hematoxylin and eosin (H&E) revealed a neoplastic lesion composed of two components. The first consisted of a multilobular proliferation of neoplastic cells, with these lobules being encapsulated and well demarcated. The histological appearance demonstrated differentiation in the three segments of the hair follicle. These lobules were separated by fibrous connective stroma that was slightly mucinous. The outer epithelial cells typically displayed a heterogeneous population, including small cells with hyperchromatic nuclei and scant cytoplasm (resembling undifferentiated cells of the hair bulb), cells with slightly eosinophilic cytoplasm and vesicular nuclei (similar to those in the lower portion of the outer root sheath), and cells with intracytoplasmic trichohyalin granules (as observed in the inner root sheath of the hair follicle). These neoplastic cells invaded the dermis in a diffuse solid growth pattern, showing marked nuclear pleomorphism and anisokaryosis with coarse chromatin and slightly eosinophilic cytoplasm. Centrally, there were cyst-like degenerative islands containing accumulations of keratin. Fourteen mitotic figures were observed per 2.37 mm², with focal areas of colliquative necrosis. The surgical margin between neoplastic and healthy tissue remained preserved. Second, in the middle region there was nodular proliferation of non-encapsulated neoplastic cells with a diffuse pattern consisting of stellate to fusiform cells with slightly eosinophilic to clear cytoplasm, nuclei were oval to elongate with moderate nuclear pleomorphism, the stroma was characterized by an amorphous myxoid eosinophilic matrix (mucin). The interaction between myxoma and trichoepithelioma may contribute to a better understanding and development within the host, allowing observation of the histological differentiation of epithelial and mesenchymal components, as well as the malignant criteria of malignant trichoepithelioma, such as dermal invasion, high mitotic index, and nuclear pleomorphism. These findings highlight the importance of histopathological analysis in diagnosis and should be included as a differential diagnosis in skin neoplasms in rabbits.

Título do Evento: X Simpósio Internacional em Ciências Veterinárias | X International Symposium in Veterinary Sciences
Cidade do Evento: Seropédica
Título dos Anais do Evento: Anais do X Simpósio Internacional em Ciências Veterinárias (X SINCVET)
Nome da Editora: Even3
Meio de Divulgação: Meio Digital

Como citar

QUILLAS, Luis Jhordy Alfaro et al.. CONCOMITANCE OF A CUTANEOUS MYXOMA AND TRICHOEPITHELIOMA IN A RABBIT (ORYCTOLAGUS CUNICULUS).. In: Anais do X Simpósio Internacional em Ciências Veterinárias (X SINCVET). Anais...Seropédica(RJ) UFRRJ, 2025. Disponível em: https//www.even3.com.br/anais/x-simposio-internacional-ciencias-veterinarias/1432142-CONCOMITANCE-OF-A-CUTANEOUS-MYXOMA-AND-TRICHOEPITHELIOMA-IN-A-RABBIT-(ORYCTOLAGUS-CUNICULUS). Acesso em: 06/11/2026