Metastatic digital carcinoma in the cat: a retrospective study of 36 cats (1992-1998)

Abstract

Thirty-six cats with bronchogenic carcinoma metastatic to the digit were identified. The mean age was 12.7 years, with no breed or sex predilection. Records from 19 cases were available for review. These cats presented with a primary complaint of lameness that involved primarily weight-bearing digits and the third phalanx. None had respiratory signs, despite the presence of pulmonary carcinoma. Course of disease was consistent in the 19 cases, with a mean survival time of 58 days from initial presentation. Amputation of affected digits was rarely palliative due to development of lesions in other digits and progressive nonrespiratory disease.

Diagnoses and Clinical Outcomes Associated with Surgically Amputated Feline Digits Submitted to Multiple Veterinary Diagnostic Laboratories

“…Although it is reported to be a rare event, there are a considerable number of case reports describing metastatic pulmonary adenocarcinoma to the digits-so-called ''lung-digit syndrome.'' 6,8,12,16,21,25 In many of the digits diagnosed with adenocarcinoma in this study, a ciliated columnar epithelium with goblet cells reminiscent of pulmonary bronchial epithelium was present. As well, 3 cats had confirmed pulmonary masses on radiographs.…”

“…8 Osteosarcoma was a relatively common diagnosis in this study, representing 5 of 63 (7.9%) neoplastic masses diagnosed. Osteosarcoma in cats is not as well described as that in dogs, with fewer studies being reported.…”

“…Reports of the frequency of SCC in the digits of cats are contradictory, with some suggesting the digit is the second most common site of SCC involving bone, 14 while others suggest that SCC in the digits is rare. 8,18 Differentiation of primary digital SCC from metastatic carcinoma can be difficult, but in the largest study of carcinomas in the digits of cats, it was found that histopathologic evaluation of digits with metastatic pulmonary carcinomas showed ciliated cells, goblet cells, and secretory material, 25 which were lacking in the SCC diagnosed in this study, and thus the SCCs in this study were determined to be primary digital tumors. The cats with SCC in this study were generally older, with the youngest being 7 years of age at the time of diagnosis.…”

“…Previous studies on neoplastic disease in the digits of cats have focused primarily on pulmonary adenocarcinomas metastatic to the digits. 8,21,25 In this study, 63 of 85 submitted amputated digits from cats contained 1 or more neoplasms, and the other 22 contained inflammation, primarily pyogranulomatous in nature, with no evidence of neoplasm. This varies dramatically from a study of diseases of the claw and claw bed in cats where only 3 of 65 cases were neoplastic.…”

Morphologic and Molecular Analysis of 39 Spontaneous Feline Pulmonary Carcinomas

“…Approximately 18% of our feline carcinoma cases metastasized to the digits, validating the previously reported syndrome of feline pulmonary carcinomas. 6 Immunohistochemistry has greatly enhanced diagnostic precision in many areas of pathology, particularly in the assessment of tumors. It is a valuable diagnostic tool that should be used with clinical and morphologic findings rather than in isolation.…”