Patient characteristics, histopathological findings and outcome in 97 cats with extranodal subcutaneous lymphoma (2007-2011)

Clinical features, MRI findings and outcome of a primary extranodal B-cell lymphoma affecting the tympanic bulla treated with chemotherapy alone

Case summary

A 2-year-old neutered female feline leukaemia virus (FeLV)-negative domestic shorthair cat was referred with an acute onset of vestibular signs. A clinical examination identified evidence of otitis externa of the right ear and enlargement of the right mandibular lymph node. MRI revealed predominantly T2 and FLAIR hyperintense and contrast-enhancing lesions affecting the right external ear canal, tympanic bulla and nasopharyngeal regions with intracranial extension. Cytology and culture and sensitivity samples collected from the middle ear via myringotomy revealed a population of intermediate to large lymphocytes consistent with lymphoma and mixed Staphylococcus chromogenes and Pasteurella species infection. PCR for antigen receptor rearrangements on the ear cytology was consistent with a B-cell rearrangement. A primary extranodal B-cell lymphoma affecting the tympanic bulla and other sites with secondary septic otitis media and interna was diagnosed. After the improvement of clinical conditions after corticosteroid, antibiotic and chemotherapy treatment, the cat was alive 22 months after diagnosis without recurrence of clinical signs.

Relevance and novel information

This is the first report of a primary extranodal B-cell lymphoma affecting the tympanic bulla with suspected involvement of the nasopharynx and cranial vault treated with chemotherapy alone in the veterinary literature. Although very rare, B-cell lymphoma should be included in the differentials for diseases affecting the inner and/or middle ear and extending intracranially in cats. Chemotherapy represents a non-invasive treatment modality with a survival of up to 22 months appearing possible.

Multifocal cutaneous non-epitheliotropic B-cell lymphoma in a cat

Case summary

Skin tumours are the second-most common form of feline cancer after haematopoietic neoplasms and are often malignant. Cutaneous lymphoma is uncommon in cats and can be classified as epitheliotropic (typically of T-cell origin) or non-epitheliotropic (either of T-cell or B-cell origin). The present study describes a case of multifocal cutaneous non-epitheliotropic B-cell lymphoma. The skin nodules were multiple and variable in size; showed rapid progression; were alopecic and erythematous in appearance and pruritic and ulcerated; and were mostly located on the trunk. Nodule biopsies revealed the presence of uniform medium-to-large round neoplastic cells that infiltrated the dermis and subcutis. The neoplasias were consistent with a round cell cutaneous tumour and did not show evidence of epitheliotropism. Furthermore, immunohistochemical assessments indicated an immunophenotype characterised by round cells with a strong membrane and cytoplasmic positivity for the CD20 antigen, consistent with a lymphocyte of B-cell origin.

Relevance and novel information

Cutaneous non-epitheliotropic B-cell lymphoma in cats is rare and was previously reported to appear as single dermal and subcutaneous masses that are variable in size and generally develop in the tarsal region. To our knowledge, this is the first report to describe multifocal cutaneous non-epitheliotropic B-cell lymphoma in a cat.

Linfoma leucemizado em felino coinfectado com os vírus da imunodeficiência felina e da leucemia felina: relato de caso

RESUMO O presente trabalho teve por objetivo relatar um caso de linfoma leucemizado em um felino coinfectado com os vírus da imunodeficiência felina (FIV) e o da leucemia felina (FeLV). Foram realizados exames de hemograma, contagem de reticulócitos, mielograma, bioquímica, teste de imunocromatografia para FIV e FeLV, imunofluorescência indireta (IFA) para FeLV, radiografia torácica e citologia renal. Esse último exame revelou um linfoma extranodal. Foi determinante para a conclusão diagnóstica a associação dos sinais clínicos corroborados com a infiltração de elevada quantidade de células linfoblásticas na medula óssea, exibindo critérios citomorfológicos de malignidade, como mitoses atípicas, relacionadas à presença de corpúsculos linfoglandulares e material hematopoiético inter-relacionado. O linfoma é uma neoplasia relativamente comum em felinos, entretanto, a apresentação leucemizada é rara, podendo representar um desafio diagnóstico clínico, o que torna fundamental a inclusão da citologia medular na prática clínica dessa espécie.

Primary angiocentric/angioinvasive T-cell lymphoma of the tympanic bulla in a feline leukaemia virus-positive cat

Case summary A 5-year-old neutered female feline leukaemia virus (FeLV)-positive domestic shorthair cat with a 5 month history of otitis media was referred for head tilt, stertor and dyspnoea. Computed tomography scan revealed soft tissue opacities inside the right tympanic bulla, with bone remodelling, and concurrent nasopharyngeal and intracranial invasion. Endoscopically guided bioptic samples were collected from the nasopharynx and middle ear. Histology revealed dense sheets of round, large, neoplastic cells, often surrounding or invading vascular walls. Neoplastic cells expressed CD3, FeLV p27 and gp70 antigens. A middle ear angiocentric/angioinvasive T-cell lymphoma was diagnosed. After improvement of clinical conditions following radiation therapy, the cat died unexpectedly. At necropsy, hepatic and splenic spread was detected.

Relevance and novel information Primary middle ear tumours are rare and their diagnosis is often delayed as clinical signs mimic more common otological conditions. Multiple bioptic specimens are pivotal for a definitive diagnosis. The young age of the cat, serology and immunohistochemistry revealed a possible transforming role of FeLV.