Feline lung-digit syndrome: A differential diagnosis for shifting, waxing and waning lameness in a cat.

The clinical presentation, cytologic findings, radiographic findings, and postmortem assessment of a cat with primary pulmonary adenocarcinoma with multiple digital metastasis are described. An unusual shifting, waxing and waning pattern of lameness, suspected to be an early manifestation of digital metastasis before any gross lesions were visible, was documented. Initial cytologic finding of a lung nodule was equivocal for diagnosis of neoplasia despite being strongly suspicious. Palliative management was short-lived, with rapid progression culminating in widespread metastasis to multiple digits, muscles, and other organs. The diagnosis of pulmonary adenocarcinoma was confirmed via necropsy and histopathology. Key clinical message: This case report highlights that feline lung-digit syndrome is an important differential diagnosis for an acute, waxing and waning, shifting leg lameness in an older cat. This pattern of lameness should raise the index of suspicion for an underlying primary lung neoplasm, and thoracic imaging (radiographs) should be considered.

Syndrome pulmonaire-digital félin : un diagnostic différentiel des boiteries changeantes, croissantes et décroissantes chez un chatLa présentation clinique, les résultats cytologiques, les résultats radiographiques et l'évaluation post mortem d'un chat atteint d'adénocarcinome pulmonaire primaire avec métastases numériques multiples sont décrits. Un schéma inhabituel de boiterie, variable, croissante et décroissante, suspecté d'être une manifestation précoce de métastases digitales avant que des lésions macroscopiques ne soient visibles, a été documenté. La découverte cytologique initiale d'un nodule pulmonaire était équivoque pour le diagnostic de néoplasie bien qu'elle soit fortement suspecte. La prise en charge palliative a été de courte durée, avec une progression rapide aboutissant à des métastases généralisées à plusieurs doigts, muscles et autres organes. Le diagnostic d'adénocarcinome pulmonaire a été confirmé par autopsie et histopathologie.Message clinique clé :Ce rapport de cas souligne que le syndrome pulmonaire-digital félin est un diagnostic différentiel important pour une boiterie aiguë, croissante et décroissante et mobile des pattes chez un chat ágé. Ce type de boiterie devrait faire suspecter une tumeur primaire du poumon sous-jacente, et une imagerie thoracique (radiographies) devrait être envisagée.(Traduit par Dr Serge Messier).

Inter- and intraobserver agreement for CT measurement of mandibular and medial retropharyngeal lymph nodes is excellent in dogs with histologically confirmed oral melanoma.

Mandibular and medial retropharyngeal lymph nodes are routinely evaluated with CT when staging dogs with oral melanomas. While size alone is considered inadequate for detecting nodal metastasis, it is critical in evaluating treatment response, as clinical decisions are based on changes in size. It is common for different radiologists to measure the size of pre- and posttreatment lymph nodes in the same patient. The objective of this retrospective, observer agreement study was to evaluate the inter- and intraobserver agreement in measuring canine mandibular and medial retropharyngeal lymph nodes by a diverse population of veterinary radiologists and trainees. Fourteen dogs with documented oral melanoma and head CT studies identified from records of a single institution were included in this study. North American veterinary radiologists and trainees were recruited to measure the mandibular and medial retropharyngeal lymph nodes; in triplicate. Prior to performing the study measurements, participants completed a training tool demonstrating the lymph node measurements. Overall, interobserver intraclass correlation coefficient (ICC) was 0.961 (95% confidence interval [CI]: 0.946, 0.972) and intraobserver ICC was 0.977 (95% CI: 0.968, 0.983), indicating excellent agreement (ICC > 0.9 considered excellent). Similar findings were noted following sub-analysis for most variables (experience, size, laterality, axis of measurement). These results suggest that follow-up measurement of the long and short axis of the mandibular lymph nodes and short axis of the medial retropharyngeal lymph nodes in the transverse plane, performed by different veterinary radiologists using the same method of measure, should have minimal impact on clinical decision making.