Histologic assessment of margin status was useful for predicting local recurrence of cutaneous malignant tumors in dogs and cats treated by means of excision alone. Method accuracy varied among tumor types and grades. Recurrence times suggested postsurgical follow-up should continue for ≥ 2 years. Results were similar for animals with infiltrated and close tumor margins, and careful postsurgical management is recommended for both.
Lymph node (LN) metastasis is a negative prognostic factor in dogs with cutaneous mast cell tumors (cMCTs). While elective lymphadenectomy of metastatic LNs improves outcome, the benefit of adjuvant medical therapy in dogs with early metastatic (HN2) LNs is debated. The aim of this retrospective multicenter study was to evaluate the therapeutic benefit of adjuvant medical therapy following surgical removal of the primary low-grade cMCT (Patnaik grade 1-2 and Kiupel low-grade) and lymphadenectomy of HN2 LNs by analyzing survival rates and patterns of recurrence.Seventy-three dogs were included: 42 received adjuvant medical treatment (chemotherapy and/or kinase inhibitors), and 31 did not. The median followup time for medically-treated dogs was 619 days: 2 experienced local recurrence, 3 nodal relapse and 4 distant relapse.For dogs undergoing surgery only, the median follow-up time was 545 days.None of them experienced local recurrence, nodal or distant relapse. Time to progression was significantly shorter in dogs receiving adjuvant medical treatment (P = 0.021). A similar tendency was observed for overall survival (P = 0.056).The current study shows that dogs with low-grade cMCTs, that undergo surgical excision of the primary tumor and elective lymphadenectomy of the HN2 regional LN harbor a good prognosis. The use of adjuvant medical treatment in these dogs does not seem to provide any benefit in terms of progression and survival.
Feline cutaneous mast cell tumors (FeCMCTs) are characterized by variable biological behavior. Development of multiple nodules and potential visceral involvement, along with inconsistency of conventional prognostic aids, justify uncertainty in differentiating benign from malignant forms. c-Kit proto-oncogene activating mutations have been reported in feline mast cell tumors (MCTs), but their prognostic relevance was not investigated. This study was performed on FeCMCTs with variable clinical outcome to assess whether Kit cytoplasmic immunohistochemical labeling can be regarded as indicative of c-Kit mutations and to evaluate the relationship between Kit dysregulation and survival. Twenty-four cats diagnosed with a primary cutaneous MCT were enrolled. Kit immunohistochemical pattern and c-Kit (exons 8, 9, 11) mutational status were assessed in 34 tumor samples. Risk factors affecting survival were a number of mitoses greater than 5 per 10 HPFs (P = .017) and cytoplasmic Kit labeling (P = .045). Increased mitotic activity was associated with Kit cytoplasmic expression (P = .01). c-Kit encoding mutations were present in 19 (56%) tumors (exon 8, 19%; exon 9, 71%; exon 11, 10%), however, they were not significantly related to protein expression and they had no influence on prognosis. Additionally, in 6 of 9 (67%) cats, multiple nodules from the same cat had different mutational statuses. Mutations in the fifth immunoglobulin-like domain of Kit occur frequently in FeCMCT, but they are variably associated with aberrant protein expression and do not appear to be strictly correlated with biological behavior. These findings need to be confirmed in larger series, and exploration of further genomic regions of c-Kit is warranted.
BackgroundOsteosarcoma (OSA) should be differentiated from other less frequent primary bone neoplasms, metastatic disease, and tumor‐like lesions, as treatment and prognosis can vary accordingly. Hence, a preoperative histologic diagnosis is generally preferred. This requires collection of multiple biopsies under general anesthesia, with possible complications, including pathological fractures. Fine‐needle aspiration cytology would allow an earlier diagnosis with a significant reduction of discomfort and morbidity.Hypothesis/ObjectivesThe aim of this study was to compare the accuracy of cytological and histologic biopsies in the diagnosis of canine osteodestructive lesions.AnimalsSixty‐eight dogs with bone lesions.MethodsRetrospective study. Accuracy was assessed by comparing the former diagnosis with the final histologic diagnosis on surgical or post‐mortem samples or, in the case of non‐neoplastic lesions, with follow‐up information.ResultsThe study included 50 primary malignant bone tumors (40 OSAs, 5 chondrosarcomas, 2 fibrosarcomas, and 3 poorly differentiated sarcomas), 6 carcinoma metastases, and 12 non‐neoplastic lesions. Accuracy was 83% for cytology (sensitivity, 83.3%; specificity, 80%) and 82.1% for histology (sensitivity, 72.2%; specificity, 100%). Tumor type was correctly identified cytologically and histologically in 50 and 55.5% of cases, respectively.Conclusions and Clinical ImportanceThe accuracy of cytology was similar to histology, even in the determination of tumor type. In no case was a benign lesion diagnosed as malignant on cytology. This is the most important error to prevent, as treatment for malignant bone tumors includes aggressive surgery. Being a reliable diagnostic method, cytology should be further considered to aid decisions in the preoperative setting of canine bone lesions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.