Temporal changes in characteristics of injection-site sarcomas in cats: 392 cases (1990–2006)

Abstract

Objective To evaluate changes in characteristics of feline injection-site sarcomas (ISSs) from 1990 through 2006. Design Retrospective case series. Animals 392 cats with a histologic diagnosis of soft tissue sarcoma, osteosarcoma, or chondrosarcoma at potential injection sites. Procedures Classification and anatomic location of tumors and signalment of affected cats were compared between ISSs diagnosed before and after publication of the Vaccine Associated Feline Sarcoma Task Force vaccination recommendations in 1996. Results From before to after publication of the vaccination recommendations, proportions of ISSs significantly decreased in the interscapular (53.4% to 39.5%) and right and left thoracic (10.2% to 3.6% and 9.1% to 1.3%, respectively) regions. On the other hand, proportions of ISSs significantly increased in the right thoracic limb (1.1% to 9.5%) and the combined regions of the right pelvic limb with right lateral aspect of the abdomen (12.5% to 25.0%) and the left pelvic limb with left lateral aspect of the abdomen (11.4% to 13.8%). Patterns of tumor classification and signalment did not change. Conclusions and Clinical Relevance Despite publication of the vaccination recommendations, a high proportion of tumors still developed in the interscapular region. There was also an increase in lateral abdominal ISSs, which are more difficult to treat and are likely attributable to aberrant placement of injections intended for the pelvic limbs. Veterinarians are complying with vaccination recommendations to some extent, but they need to focus on administering vaccines as distally as possible on a limb to allow for complete surgical margins if amputation of a limb is required.

Epidemiological and morphological analysis of feline injection site sarcomas

“…However, in our analysis FISS in these body regions were common (74% of cats included in this study). The results are worse than those obtained in the USA, were the proportion of FISS decreased from 1990 to 2006: 53.4% to 39.5%, respectively, in the interscapular region (Shaw et al 2009). In our research, among 149 cats with precisely known location of a mass, in 52% of FISS tumor were growing in the interscapular or periscapular region.…”

“…There had been a shift in FISS location from 1996 when Vaccine-Associated Feline Sarcoma Task Force recommended vaccination sites for FeLV and rabies vaccines, adopted later by the American Association of Feline Practitioners in 1997 (Shaw et al 2009). Before 1996 feline ISS had been found 5 times more frequently in the interscapular region than in any other location.…”

“…Before 1996 feline ISS had been found 5 times more frequently in the interscapular region than in any other location. After 1996, there was a significant shift in tumor location to the hind legs and the lateral abdomen (Shaw et al 2009). Proportion of FISS decreased in the interscapular region from 53.4% to 39.5% and increased on the right hind leg (recommended place for rabies vaccination) from 1.1% to 9.5% and on the left hind leg (recommended place for leukemia vaccination) with the left lateral abdomen region from 11.4 to 13.8% (Shaw et al 2009).…”

“…After 1996, there was a significant shift in tumor location to the hind legs and the lateral abdomen (Shaw et al 2009). Proportion of FISS decreased in the interscapular region from 53.4% to 39.5% and increased on the right hind leg (recommended place for rabies vaccination) from 1.1% to 9.5% and on the left hind leg (recommended place for leukemia vaccination) with the left lateral abdomen region from 11.4 to 13.8% (Shaw et al 2009). In the United Kingdom the most commonly affected site is still the interscapular region (84%), followed by femoral (6%), flank (5%), lumbar (3%) and gluteal (2%) regions (Kass et al 2003).…”

Extraskeletal osteochondroma on a cat´s elbow

“…Another feline extraskeletal malignant tumour is chondrosarcoma, which is a rare soft tissue proliferation of malignant cells with chondroid differentiation (Romanucci et al 2005). They have been reported more commonly in the extremities of cats but they can also occur extraskeletally (Durham et al 2008;Johnson & Watson 2005;Romanucci et al 2005;Shaw et al 2009). Owing to the limited number of cases, it is not certain whether extraskeletal chondrosarcomas are more or less aggressive than the skeletal forms, although it is thought that it depends on the type and success of the therapeutic intervention (Durham et al 2008;Romanucci et al 2005;Shaw et al 2009).…”