Comparison of CT features of 79 cats with intranasal mass lesions

Objectives This retrospective multicentre study compared the CT characteristics of cats diagnosed with intranasal mass lesions to determine if defining imaging features exist between different tumour types and between neoplastic and non-neoplastic lesions. Methods The medical records of two institutions were reviewed for cats with CT findings consistent with an intranasal mass lesion with subsequent histopathological examination. For each CT scan the mass location, growth pattern, margin distinction, contrast enhancement pattern and presence of intralesional areas of mineralisation or necrosis were recorded. The presence of facial deformity, the location and type of bone changes, extranasal extension of the mass lesion and the regional lymph nodes size, contrast pattern and hilus visibility were also documented. Results Thirty-five cats with nasal lymphoma, 28 cats with non-lymphomatous nasal neoplasia (carcinoma or sarcoma) and 16 cats with inflammatory lesions met the inclusion criteria. Cats with non-lymphomatous nasal neoplasia were more likely to show unilateral nasal changes (odds ratio [OR] 3.9), areas of intralesional calcification (OR infinity) and extension of the mass lesion within the frontal sinus (OR 4.5), while cats suffering from nasal lymphoma were more likely to show a mixed (OR 4.5) and expansile growth pattern (OR 7.8), and a regional lymphadenomegaly (OR 2.4). The CT findings in cats diagnosed with inflammatory mass-like lesions were highly variable and overlapped with findings for nasal neoplasms but were significantly associated with the absence of bony changes to the nasal cavity boundaries (OR 10.2). Conclusions and relevance Findings from the current study support the ability of CT to aid in the discrimination of tumour type in cats presented with an intranasal mass lesion.

MRI findings, including diffusion-weighted imaging, in seven cats with nasal lymphoma and two cats with nasal adenocarcinoma

Objectives Case series summary Primary nasal tumours in cats are rare, with lymphoma being the most common feline nasal tumour, followed by adenocarcinoma. Although CT can reliably detect feline nasal tumours, there are no specific CT features that identify each tumour type. To our knowledge, there have been no reports describing MRI findings, including diffusion-weighted imaging (DWI), for nasal lymphomas and adenocarcinomas in cats. Therefore, this retrospective study aimed to evaluate the MRI findings of nasal lymphoma and adenocarcinoma, including qualitative and quantitative analysis of DWI. Methods MRI examination was performed on seven cats with histologically confirmed lymphoma and on two with adenocarcinoma. The MRI protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. Apparent diffusion coefficient (ADC) values were measured using DWI. Contrast agent was not used in one cat with lymphoma. Results In those with lymphoma, three (43%) were iso- and hyperintense on T2WI, seven (100%) were iso-intense on T1WI, five (83%) exhibited mild heterogeneous enhancement, including a prominent region of non-enhancement on post-contrast T1WI, and seven (100%) cats exhibited hyperintensity on DWI. The median ADC values were 0.45 × 10−3 mm2/s (range 0.37–0.53 × 10−3 mm2/s). For adenocarcinoma, two (100%) were iso- and hyperintense on T2WI, two (100%) were iso-intense on T1WI, two (100%) exhibited marked heterogeneous enhancement on post-contrast T1WI and two (100%) were iso-intense on DWI. The median ADC values were 1.08 × 10−3 mm2/s (range 0.88–1.27 × 10−3 mm2/s). The median ADC values of lymphoma tended to be lower than adenocarcinoma ( P = 0.056). Conclusions and relevance Determining ADC value and tumours with a large area of non-enhancement may be helpful in differentiating nasal lymphoma from nasal adenocarcinoma.

Nasal adenocarcinoma as a suspected secondary malignant neoplasm in a cat previously treated for nasal lymphoma

Case summary A case of nasal adenocarcinoma as a suspected secondary malignant neoplasm following definitive radiation therapy and multiagent chemotherapy for nasal lymphoma is described. An 11-year-old spayed female domestic shorthair cat was presented for a 3-week history of progressive facial swelling located over the nasal planum and extending to the medial canthus of the right eye. The cat was previously diagnosed with nasal lymphoma and treated with chemotherapy and definitive radiation 2.5 years prior. Although a definitive diagnosis could not be obtained via cytology, recurrent lymphoma was suspected based on the cat’s history and recurrent clinical signs. A lymphoma-directed chemotherapy protocol was attempted, but no clinical response was achieved. The cat was euthanased owing to progressive clinical signs and a diagnosis of nasal adenocarcinoma was made on necropsy examination. Both the original diagnosis of nasal lymphoma and the secondary diagnosis of nasal adenocarcinoma were confirmed with immunohistochemistry. Relevance and novel information Secondary malignant neoplasm following radiation therapy is infrequently reported in the veterinary literature. In the few reports that exist, most have described sarcoma development in the dog following radiation therapy. In the present report, we describe a cat with a suspected radiation-induced nasal adenocarcinoma that developed 2.5 years after definitive radiation treatment for nasal lymphoma.

Linfoma No Hodgkin extranodal NK/T nasal Extranodal Non-Hodgkin NK/T nasal Lymphoma

Los linfomas no Hodgkin se originan a partir de linfocitos B, T y natural killer (NK) maduros, dentro de estos existe un subtipo poco frecuente de linfoma que se desarrolla a partir de células NK y en menor porción por células T citotóxicas denominado “Linfoma extra ganglionar de linfocitos NK/T de tipo nasal.” Este tipo se suele presentar en sujetos masculinos, entre 40-50 años y en zonas de Latinoamérica y el Sureste Asiático. Se caracteriza por tener una rápida progresión y causar destrucción de las estructuras de la línea media facial, los síntomas B son poco frecuentes(1-5). El diagnóstico se basa en anatomía patológica e inmunohistoquímica positiva para marcadores de células natural killer o linfocitos T, así como la presencia del virus Epstein Barr(7,8). El tratamiento requiere un abordaje interdisciplinario entre los servicios de hematología y otorrinolaringología. El pronóstico depende del estadiaje del tumor al momento del diagnóstico y de los factores de riesgo que presente el paciente(5).