Atypical spleen hemophagocytic histiocytic sarcoma in a dog

Background: The histiocytic sarcoma (HS) complex is a set of malignant neoplasms originating from interstitial dendritic cells or macrophages. When it involves macrophages of the splenic red pulp and bone marrow, it is referred to as hemophagocytic histiocytic sarcoma (HHS). HHS behaves more aggressively than HS and is usually fatal. HHS can be diagnosed by cytological and histopathological examination of neoplastic tissue. HHS is confirmed by immunohistochemistry using an anti-CD11d antibody. This neoplasm is often confused with immune-mediated hemolytic anemia or Evans syndrome due to erythrophagocytosis and platelet consumption. The clinical presentation of the animals progresses with evident anemia and thrombocytopenia, leading to signs such as prostration, inappetence, and pale mucosa, making diagnosis challenging and often late. This study aimed to report the clinic-pathological aspects of a canine with atypical hemophagocytic splenic HS. Case: A 4-year-old male Shih-Tzu canine was referred to the Veterinary Hospital with a history of prostration and anorexia. Pale mucous membranes were observed on physical examination. Blood tests revealed non-regenerative anemia, leukopenia, and thrombocytopenia. Serum protein levels were below the reference values for the species in biochemical examinations. Hemoparasitosis was suspected; however, the result of the polymerase chain reaction was negative. Abdominal ultrasound revealed a splenomegaly with heterogeneous parenchyma and a slightly irregular surface, but no visible mass in the spleen. Due to the difficulty of stabilizing the patient, even after successive transfusions, the animal underwent exploratory laparotomy with medial access and posterior splenectomy. Subsequently, the spleen was surgically removed, fixed in 10% buffered formalin, and processed routinely. Macroscopically, it had an irregular reddish-brown capsular surface. Histopathological examination of the spleen revealed a densely cellular neoplasm composed of round to spindle cells (histiocytes) arranged haphazardly in variably sized sheets separating the pre-existing spleen stroma. These histopathological findings were consistent with a histiocytic malignant neoplasm. Immunohistochemical analysis was performed to better define the origin of the histiocytic neoplasm. Neoplastic cells showed positive immunostaining of more than 80% of tumor cells for the CD11d antibody and weak immunostaining for CD11c and lysozyme. The patient survived for less than 30 days after the first hospital visit. Discussion: The diagnosis of HHS was based on the histological characteristics and positive immunostaining of more than 80% of the tumor cells for the CD11d antibody. HHS is an extremely aggressive and rare tumor that affects elderly dogs of any breed. In this study, HHS had atypical histologic characteristics, in which erythrophagocytosis and hemosiderin were not observed within macrophages. HHSs arise from macrophages of the red pulp of the spleen or bone marrow and express the b2 integrin, CD11d, and have low expression of CD1 and CD11c, which are predominantly expressed by non-hemophagocytic HS. The hematological and biochemical changes observed in this case were similar to those described in other dogs with HHS. Treatment of HHS is only palliative. Erlichia ewingii, E. canis, Anaplasma phagocytophilum, A. platys, Borrelia burgdorferi, Dirofilaria immitis, Leishmania infantum and immune-mediated hemolytic anemia are the main differential diagnoses because they cause anemia and thrombocytopenia accompanied by splenomegaly.

Treatment of canine multicentric lymphoma through vascular access port vs. peripheral venous catheter

Background: Vascular access port (VAP) was developed for the administration of chemotherapeutic agents, minimizinglocal drug reactions and complications associated with migration of peripheral venous catheter (PVC) in humans. Thedevice is widely used in human oncology and has gained importance in veterinary oncology, especially in long treatmentregimens, as in the case of canine lymphoma. VAP favors therapy and the animals life quality. The aim of this study wasto describe the use of VAP in dogs, comparing to PVC access, during canine lymphoma chemotherapeutic treatment.Materials, Methods & Results: Eleven dogs with multicentric lymphoma which required chemotherapy were selectedfor the study. The dogs were randomly allocated to two groups with five and six animals, and each group received thechemotherapy protocol through the PVC (n= 5) or VAP (n= 6). For the sake of standardization, assessments were madewhenever the dogs received vincristine sulfate, despite the use of the infusion system in all sessions of the MadisonWisconsin protocol. A VAP was implanted into the right external jugular vein of six dogs under inhalational anesthesia,using the Seldinger technique. Systolic blood pressure (SBP) levels and handling time during chemotherapy sessions werecompared in both groups in three time periods during the procedures: 10 min after arrival to each chemotherapy (P1);immediately after placement of the PVC or puncture of the VAP reservoir (P2); and at the end of chemotherapy (P3). Thearithmetic mean of five consecutive assessments was used in each time period. In the chemotherapy sessions, the mean ofSBP variation decreased statistically significant in the VAP group compared to PVC group. SBP decreased from P1 to P2and from P1 to P3 in all sessions (S1, S2, and S3) in the VAP group, and increased in the PVC...(AU)

Treatment of canine multicentric lymphoma through vascular access port vs. peripheral venous catheter

Background: Vascular access port (VAP) was developed for the administration of chemotherapeutic agents, minimizinglocal drug reactions and complications associated with migration of peripheral venous catheter (PVC) in humans. Thedevice is widely used in human oncology and has gained importance in veterinary oncology, especially in long treatmentregimens, as in the case of canine lymphoma. VAP favors therapy and the animals life quality. The aim of this study wasto describe the use of VAP in dogs, comparing to PVC access, during canine lymphoma chemotherapeutic treatment.Materials, Methods & Results: Eleven dogs with multicentric lymphoma which required chemotherapy were selectedfor the study. The dogs were randomly allocated to two groups with five and six animals, and each group received thechemotherapy protocol through the PVC (n= 5) or VAP (n= 6). For the sake of standardization, assessments were madewhenever the dogs received vincristine sulfate, despite the use of the infusion system in all sessions of the MadisonWisconsin protocol. A VAP was implanted into the right external jugular vein of six dogs under inhalational anesthesia,using the Seldinger technique. Systolic blood pressure (SBP) levels and handling time during chemotherapy sessions werecompared in both groups in three time periods during the procedures: 10 min after arrival to each chemotherapy (P1);immediately after placement of the PVC or puncture of the VAP reservoir (P2); and at the end of chemotherapy (P3). Thearithmetic mean of five consecutive assessments was used in each time period. In the chemotherapy sessions, the mean ofSBP variation decreased statistically significant in the VAP group compared to PVC group. SBP decreased from P1 to P2and from P1 to P3 in all sessions (S1, S2, and S3) in the VAP group, and increased in the PVC...

Carcinoma prostático felino / Feline prostatic carcinoma

Background: Prostatic cancer is a rare condition in cats but should be included as a differential diagnosis whenever middleaged cats present lower urinary tract signs, such as dysuria and hematuria. Abdominal ultrasound can indicate the disease,but fine-needle aspiration cytology and histopathology are necessary to establish the neoplastic origin and the therapeuticplan. Because of the limited data, no standard-of-care treatment or prognostic information exists in cats with prostate carcinoma. This report describes the clinical signs, diagnosis and surgical approach in a case of prostatic carcinoma in a cat.Case: A 6-year-old, intact male, domestic short-haired cat was presented with a 3-day history of dysuria, hematuria, inappetence, constipation, lethargy and prostration. On physical examination, the cat was in a very poor general conditionand abdominal palpation revealed firm mass located caudally to the urinary bladder. The urinary bladder presented highrepletion degree, while the large bowel was distended and presented soft faecal content. Blood count, serum biochemistryand urinalysis showed neutrophilic leukocytosis, hypoalbuminemia and high creatinine level, and severe hematuria, respectively. Abdominal ultrasound showed a mass located in the prostatic area with hypoechogenic and slightly heterogeneousparenchyma, measuring 3.3 x 3.0 cm. Echo-guided trans-abdominal fine-needle aspiration of the prostate was performed.Microscopically, the cells were round with basophilic cytoplasm, and had round to ovoid nuclei, dense chromatin andprominent nucleoli. Some cells were binucleated and mild anisocytosis and marked anisokaryosis were documented. Thesefindings were compatible with malignant prostatic neoplasia. After initial clinical stabilization, the patient underwent anexploratory laparotomy for tumor resection...(AU)

Carcinoma prostático felino / Feline prostatic carcinoma

Background: Prostatic cancer is a rare condition in cats but should be included as a differential diagnosis whenever middleaged cats present lower urinary tract signs, such as dysuria and hematuria. Abdominal ultrasound can indicate the disease,but fine-needle aspiration cytology and histopathology are necessary to establish the neoplastic origin and the therapeuticplan. Because of the limited data, no standard-of-care treatment or prognostic information exists in cats with prostate carcinoma. This report describes the clinical signs, diagnosis and surgical approach in a case of prostatic carcinoma in a cat.Case: A 6-year-old, intact male, domestic short-haired cat was presented with a 3-day history of dysuria, hematuria, inappetence, constipation, lethargy and prostration. On physical examination, the cat was in a very poor general conditionand abdominal palpation revealed firm mass located caudally to the urinary bladder. The urinary bladder presented highrepletion degree, while the large bowel was distended and presented soft faecal content. Blood count, serum biochemistryand urinalysis showed neutrophilic leukocytosis, hypoalbuminemia and high creatinine level, and severe hematuria, respectively. Abdominal ultrasound showed a mass located in the prostatic area with hypoechogenic and slightly heterogeneousparenchyma, measuring 3.3 x 3.0 cm. Echo-guided trans-abdominal fine-needle aspiration of the prostate was performed.Microscopically, the cells were round with basophilic cytoplasm, and had round to ovoid nuclei, dense chromatin andprominent nucleoli. Some cells were binucleated and mild anisocytosis and marked anisokaryosis were documented. Thesefindings were compatible with malignant prostatic neoplasia. After initial clinical stabilization, the patient underwent anexploratory laparotomy for tumor resection...