Periarticular histiocytic sarcoma with heart metastasis in a cat

A 4-year-old intact female domestic short-haired cat was referred for recommendations about adjuvant medical treatment 1 month after left forelimb amputation due to periarticular histiocytic sarcoma (HS). At presentation, physical abnormalities were limited to enlarged ipsilateral superficial cervical and axillary lymph nodes. Routine blood analysis, abdominal ultrasound, and thoracic radiology were unremarkable. The cat initially received lomustine without any adverse events. Four weeks later, the cat developed severe acute respiratory distress. Results of thoracic radiographs and transthoracic echocardiographic analysis were suggestive of pulmonary and heart metastasis. Due to the cat's poor clinical condition and prognosis, the owner elected euthanasia, and a necropsy was performed. Based on gross pathology, histopathology, and immunohistochemistry, an HS with nodal, renal, pulmonary, and heart (right auricular and right ventricular) metastases was diagnosed. This case represents the first description of HS with a heart metastasis in a cat, providing further insight into the clinical course and metastatic behavior of this rare malignant neoplasm. Clinicians should be aware of this site of metastasis and consider HS in the list of differential diagnoses for secondary heart tumors in cats

Lymphadenectomy improves outcome in dogs with resected Kiupel high-grade cutaneous mast cell tumours and overtly metastatic regional lymph nodes

Historically, the prognosis for dogs with stage II Kiupel high-grade cutaneous mast cell tumours has been considered poor

Environmental risk factors for the development of oral squamous cell carcinoma in cats

Background: Risk factors for oral squamous cell carcinoma (OSCC) in cats are derived from a single study dated almost 20 years ago. The relationship between inflammation of oral tissues and OSCC is still unclear. Objectives: To investigate previously proposed and novel potential risk factors for OSCC development, including oral inflammatory diseases. Animals: Hundred cats with OSCC, 70 cats with chronic gingivostomatitis (CGS), 63 cats with periodontal disease (PD), and 500 controls. Methods: Prospective, observational case-control study. Cats with OSCC were compared with an age-matched control sample of client-owned cats and cats with CGS or PD. Owners of cats completed an anonymous questionnaire including demographic, environmental and lifestyle information. Results: On multivariable logistic regression, covariates significantly associated with an increased risk of OSCC were rural environment (OR: 1.77; 95% CI: 1.03-3.04; P =.04), outdoor access (OR: 1.68; 95% CI: 1.07-2.63; P =.02), environmental tobacco smoke (OR: 1.77; 95% CI: 1.05-3; P =.03), and petfood containing chemical additives (OR: 1.98; 95% CI: 1.04-3.76; P =.04). Risk factors shared with CGS and PD were outdoor access and petfood containing chemical additives, respectively. A history of oral inflammation was reported in 35% of cats with OSCC but did not emerge as a risk factor. Conclusions and Clinical Importance: The study proposes novel potential risk factors for OSCC in cats. Although a history of inflammatory oral disease was not significantly more frequent compared with random age-matched controls, OSCC shared several risk factors with CGS and PD

Minimal residual disease in lymph nodes after achievement of complete remission predicts time to relapse in dogs with large B-cell lymphoma

Most dogs with large B-cell lymphoma (LBCL) that undergo chemotherapy and achieve clinical complete remission (CR) eventually relapse. However, time to relapse (TTR) is unpredictable. The aims of this prospective study were to assess the influence of post-chemotherapy lymph node (LN) infiltration by large CD21+ cells using flow cytometry (FC) on TTR, and to establish a cut-off value of prognostic significance. Dogs with newly-diagnosed, completely staged LBCL in CR after treatment were enrolled. Minimal residual disease (MRD) analysis by FC was performed on LN aspirates. TTR was calculated between MRD and relapse. Thirty-one dogs were enrolled: 4% had stage V disease, and DLBCL was the most common histotype (74%). Based on LN infiltration at MRD evaluation, 3 groups were created: 1) acellular samples; 2) 640.5% infiltration; and 3) >0.5% infiltration. Overall median TTR was 154 days (range, 31-1974): 22 (71%) dogs relapsed during the study period, whereas 9 (29%) dogs did not. The difference among the 3 groups was significant (p=0.042 log-rank test): median TTR was not reached for dogs with LN infiltration 640.5% (range, 195-429 days), 164 days (range 63-1974) for dogs with acellular LN samples, and 118 days (range, 31-232) for dogs with LN infiltration >0.5%. These results demonstrate that MRD assessment by FC on LN aspirates in dogs with LBCL in clinical CR predicts TTR. LN infiltration by >0.5% large CD21+ cells after treatment is an unfavorable prognostic factor

Timely adjuvant chemotherapy improves outcome in dogs with non-metastatic splenic hemangiosarcoma undergoing splenectomy

Timely delivery of adjuvant chemotherapy has been shown to be advantageous in many human cancers and canine osteosarcoma. Adjuvant chemotherapy has been shown to improve outcome for canine splenic hemangiosarcoma. The aim of this retrospective study was to investigate whether timely adjuvant chemotherapy administration resulted in better outcome in dogs with non-metastatic splenic hemangiosarcoma undergoing splenectomy. Medical records were searched for dogs with non-metastatic, splenic hemangiosarcoma that received splenectomy and adjuvant chemotherapy. The number of days from surgery to the first chemotherapy dose (StoC) was evaluated to identify the cut-off value associated with the best survival advantage. StoC and other possible prognostic factors were tested for influence on time to metastasis (TTM) and overall survival (OS). Seventy dogs were included. Median StoC was 20 days (range: 4-70). The time interval associated with the greatest survival benefit was 21 days. Median TTM and OS of dogs with StoC <= 21 days were significantly longer than those with StoC > 21 days (TTM: 163 vs. 118 days, p = .001; OS: 238 vs. 146 days, p < .001). On multivariable analysis, StoC > 21 days was the only variable significantly associated with increased risk of tumour progression (HR 2.1, p = .010) and death (HR 2.3; p = .008). Starting adjuvant chemotherapy within 21 days of surgery may be associated with a survival benefit in dogs with non metastatic splenic hemangiosarcoma, possibly due to the early targeting of newly recruited metastatic cells after surgery