Clinical, Pathological and Immunohistochemical Evaluation of a Primary Hemangiosarcoma in a Pinscher Dog

Background: Hemangiosarcoma (HSA) is a malignant tumor that arises from the vascular endothelium affecting more often dogs than other species as cats, cows and horses. It comprises approximately 2% of all tumors in dogs. The most common primary site for the HSA in dogs is the spleen, and other locations include the right atrium, pericardium, liver andprostate. Other authors have reported this tumor in lungs, kidney, oral cavity, muscle, bone, urinary bladder, left ventricle, tongue and retroperitoneum. Due to the importance of the HSA in canine species, the aim of this study was to describe the clinical and pathological fndings, besides therapeutic protocol in an unusual case of HSA.Case:A six-year-old male pinscher was referred to the veterinary hospital with a history of cyanosis and choking. The animal was submitted to radiographic examination in lateral cervical view, which identifed the presence of a mass of 1.2 cm in diameter near the pharynx. In order to evaluate the oral cavity, general anesthesia was performed, and it was possible to see a soft, rosy, circumscribed and vascularized lump in pharyngeal region. Due to suspicion of neoplasm, excisional biopsywithout surgical margin was performed. The histopathological exam diagnosed hemangiosarcoma. Immunohistochemistry against vimentin, factor VIII, VEGF and Ki67 was performed and confrmed diagnosis of low grade hemangiosarcoma. Antineoplastic chemotherapy protocol was initiated with doxorubicin and cyclophosphamide every 21 days totaling sixsessions. However, the animal died after the cyclophosphamide intoxication with a three-fold recommended dose (660 mg/m² total in the last session), showing a median survival rate of 220 days.Discussion: The most common primary site for HSA in dogs is the spleen. The pharyngeal location is rare, with only a few reports in literature. In the present case, solitary tumor was observed in pharynx with no involvement of other organs, evidenced by radiographic examination, abdominal ultrasound and echocardiogram, suggesting that pharynx was theprimary location of the tumor. Main features of HSA comprise a solitary nodule or multifocal lesions within the organ or widely disseminated. Histologically, they consist of pleomorphic immature endothelial cells with formation of vascular spaces with variable amount of blood and/or thrombi. In some cases, HSA shows a polymorphic subtype and immunohistochemistry is necessary to provide a defnitive diagnosis. The sample was submitted to histopathological examination which revealed proliferation of endothelial cells with pronounced pleomorphism ranging from polygonals to ovoid, sparse cytoplasm, round to oval nucleus with visible nucleolus, few mitotic fgures, some of them, aberrant, which confrmed diagnosis of HAS. Due to the unusual location, we performed immunohistochemical staining for vimentin, factor VIII,VEGF and Ki67 antibodies to confrm mesenchymal origin of the tumor. In IHC, it was possible to identify positive reac tion for vimentin protein, factor VIII, VEGF and few Ki67 positive cells, confrming histopathological diagnosis. Despite literature describes an aggressive biological behavior of canine HSA, with common occurrence of metastasis, recurrencewas not observed at the site of the removal of the tumor. In histopathological evaluation, it was observed low number ofmitoses, besides the low Ki67 expression on IHC, featuring a low grade tumor with minor ability to metastasize. To the author’s knowledge, this case describes an unusual presentation of HSA, with low metastatic potential, in which chemo therapy protocol achieved survival time of 220 days.Keywords: angiosarcoma, dogs, immunohistochemistry, pharynx

Electrochemotherapy Associated with Calcium Electroporation in Metastatic Feline Cutaneous Malignant Melanoma

Background: Calcium electroporation (CaEP) is a novel therapeutic treatment that has been studied for cancer due to its selective killing cancer cells by necrosis and danger signals. Besides that, electrochemotherapy (ECT) is an effective local treatment that involves the administration of chemotherapeutic drugs followed by delivery of electrical pulses to the tumor. The combination with ECT and CaEP has been reported in literature suggesting that additional response of immune system could have been enhanced by electroporation with calcium. This case, report on the successful treatment with CaEP combined with ECT for treatment of a regional metastasis in a feline model of malignant melanoma.Case: A 9-year-old, mixed breed cat was referred to the veterinary clinic with a 2-month history of cutaneous peripalpebral plaque lesion (0.19 cm³) and a submandibular lymph node enlargement (0.5 cm³). Incisional biopsy of the cutaneous lesion and fine-needle aspiration of submandibular lymph node confirmed a cutaneous melanoma with submandibular lymph node metastasis. Tumor staging was set in T1N1M0 according to WHO staging criteria. ECT for the primary lesion and lymph node metastasis was proposed. For the ECT, bleomycin (15,000 UI/m²) application was performed intravenous followed by electroporation (8 pulses of 100 μs at 1000 V/cm, and 1 Hz) using a needle array electrode consisted of two parallel rows with six needles in each row. At 28-day post-ECT complete remission of the primary tumor and metastatic foci was achieved. However, 120 days after ECT, recurrence was observed in submandibular and retropharyngeal lymph nodes. A second ECT approach was performed adding to bleomycin the intra lymph nodal application of calcium gluconate. The dose of calcium gluconate was diluted in an isotonic 0.9% NaCl solution resulting in a low concentration at 9 mM, injected in both metastatic lymph nodes (submandibular total volume: 1.4 ml; retropharyngeal total volume: 0.5 mL) and pulses were delivered immediately after drug administration. No systemic adverse effects were observed. Local adverse effects were considered mild as transitory edema and ulceration post procedure. One-week post-ECT+CaEP, complete remission of local metastasis occurred. However, the patient achieved five months disease free interval, and died during a surgical approach, achieving nine months of survival time.Discussion: Feline cutaneous malignant melanoma is an aggressive disease with a short survival time for the patients with mean of 4.5 months. CaEP is a novel anticancer treatment that has been study in the past years due to its selective killing cancer cells by necrosis and danger signals. The CaEP induces supraphysiological calcium influx into neoplastic cells leading to acute ATP depletion and necrosis of tumor cells. This use could be an interesting therapeutic choice for both human and veterinary medicine. In this patient, it was demonstrated a good clinical response with its use, showing temporarily tumor remission from the case presented with disease free interval of five months when compared to other report of two months. This description showed that ECT associated with CaEP improved outcome of regional melanoma lymph node metastasis in a cat. However, further investigations are needed to understand the use of CaEP in patients for local control metastasis as well as evaluate the use of both modalities to determine its synergistic effect

Primary Perianal Malignant Melanoma in a Dog - Combination Therapy

Background: Melanocytic neoplasm can arise from melanocytes in any location of the body. Malignant melanoma (MM) has a poor prognosis in dogs and presence of lymphvascular invasion, distant metastasis, or mitotic activity present prognostic value. Primary melanoma affecting the gastrointestinal tract has been rarely reported in veterinary literature, thus the prognosis affecting gastrointestinal tract is unknown. Electrochemotherapy (ECT) is an effective local treatment which combines chemotherapeutic drugs mainly bleomycin or cisplatin followed by the delivery of permeabilizing electrical pulses However, other hydrophilic drugs seem to present an increase cytotoxic effect such as carboplatin.Case: A 9-year-old mixed-breed neutered dog was referred to a private clinic with a mass in the perianal region diagnosed as perianal melanoma. No metastasis was observed on abdominal ultrasound nor chest x-ray (3 views). Clinical signs noted were tenesmus, hemorrhagic discharge, weight loss and hyporexia. Considering the tumor volume (16.0 x 10.0 cm), a neoadjuvant ECT session was proposed. The authors opted for carboplatin (300 mg/m², intravenously), administered over 20 min and cisplatin intratumorally (1 mg/cm³, equivalent to 1 mL/1cm³; total volume 20 mL) administered in the upper parts of the mass that could be reached while avoiding drug leakage. After administration, sequences of eight biphasic pulses, (100 microseconds), with a voltage ranging from 650-1,000V/cm (pulse generator Onkodisruptor®) using a hexagonal/single pair and plate electrode were delivered. At day 30th, a partial response was observed accordingly to RECIST system, with tumor size of 5.0 x 5.0 cm (65.4 cm³). A second ECT session was performed with the same previous protocol, but with a decreased dosage of carboplatin (240 mg/m² consistent with 20% reduction) due to adverse effects in the first session, resulting in stable disease at day 60th (30 days after second ECT). Then, we proposed a surgical excision of the mass including partial resection of ventral rectum with intraoperative ECT. Afterwards, it was observed fecal incontinence that did not resolved after time but did not significant cause a morbidity in the patient. Patient achieved a disease-free interval (DFI) of 700 days and survival time of 730 days. Unfortunately, patient died due to distant metastasis.Discussion: Surgery is still the cornerstone treatment for MM in dogs, regardless anatomic site. However, in perianal region, wide or radical local surgical excision is a challenge due to anatomic region which precluded most of the time to achieve complete margins. In this report, the origin of the tumors was not defined since no normal tissue was found surrounding tumors cells probably due to tumor invasion and destruction of surrounding tissue. Thus, based on the previous literature, this tumor could have been arisen from rectum wall or anal sac. The longer DFI and survival time from this patient is superior from the most veterinary cases in literature which combined different types of treatment such as surgery, chemotherapy, immunotherapy, palliative care or ECT. Neoadjuvant ECT leaded to a reliable approach for partial remission in order to perform a better surgical approach in this case report. To conclude, ECT may be an option for partial remission and local control in regions which anatomic limitation is a challenge for wide excision.Keywords: bleomycin, carboplatin, cisplatin, electroporation, melanocytic tumor

Pituitary Carcinoma in a Bitch: Clinical, Tomographic, Histopathological and Immunohistochemistry Findings

Background: Primary pituitary carcinoma is rarely reported in dogs and only few reports describe its malignancy. In veterinary literature, primary pituitary carcinomas correspond up to 2.4% to 3.4% of intracranial neoplasms found in dogs and information regarding its biological behavior is quite limited.  In humans, primary pituitary carcinomas represent less than 1.0% of all tumors found in the pituitary gland. The proposed classification for pituitary carcinoma in humans and dogs determines that the tumor must have its origin in adenohypophyseal region and disseminated metastasis by cerebrospinal fluid or systemically to other organs must be observed. In dogs, a few reports have described primary pituitary carcinoma. The goal of this report was to describe clinical, tomographic, histopathological and immunohistochemistry features of a dog with primary pituitary carcinoma with adjacent invasion. Case: A 7-year-old female spayed Golden Retriever dog was assessed by general practice due progressive weight loss, muscular atrophy, lethargy, blindness, head pressing, and hyporexia for 21 days. Computed tomography (CT) showed a cerebral parenchyma with expansive extra-axial base formation, originating from sella turcica topography, measuring about 2.0 centimeter dorsally, displacing the third ventricle, suggesting the diagnosis of pituitary neoplasia. The hormones thyroid-stimulating hormone (TSH) and total thyroxine (T4) as well as stimulation ACTH test were unremarkable. After 7 days, neurological clinical signs progressed and unfortunately the patient died ten days later after hospitalization. A necropsy exam revealed pituitary gland with increased dimensions (2.5 x 2.0 cm). Histopathological findings revealed tumor proliferation in pituitary gland. The neoplasm showed invasion to the nervous parenchyma and metastatic foci between the brain lobes. Immunohistochemistry was positive for keratin and neuron-specific enolase and negative for epithelial membrane antigen, S-100 protein, glial fibrillary acidic protein, estrogen receptor, CD34, chromogranin, somatostatin, and ACTH. The clinical, histopathological and immunohistochemistry findings supported the diagnosis of primary pituitary carcinoma. Discussion: There is lack information regarding pituitary carcinoma prevalence in dogs, and little is known about its pathological and clinical features. The patient showed a shorter survival time (30 days after the onset of clinical signs) for a non-hormonally functional tumor that presented with acute onset of neurological signs due to local effect of an expanding mass, also described in others pituitary carcinoma reports. It was observed a metastatic focus of pituitary neoplasia between cerebral hemispheres, leading us to conclude to be a pituitary carcinoma. Adjacent infiltration was noticed by the presence of neoplasm invasion to the synoptic nervous parenchyma and metastatic foci between the brain lobes as well as the presence of a non-delimited nodular area of neoplastic implantation between the cerebral hemispheres, and optic nerve compromised by neoplasm cells. The data reported here showed that a negative ACTH receptor in neoplasm with 10% Ki-67 proliferation index with no history of clinical signs of pituitary-dependent hyperadrenocorticism (PDH). Pituitary adenocarcinomas are thought to be more often non-secretors. CT findings reveled a pituitary mass of 2.5 cm in vertical height suggesting a pituitary macrotumor although there is lack of description for pituitary carcinomas in veterinary literature. The animal had a fast deterioration of his clinical condition and quickly came to death, suggesting poor biological behavior of the tumor. Keywords: adrenocorticotropic hormone, case report, dog, pituitary tumors

Schirmer tear test, a useful diagnosis tool for the clinician / Teste lacrimal de Schirmer, uma ferramenta diagnóstica útil para o clínico

It was evaluated the Schirmer Tear Test 1 (STT-1) in 100 dogs randomly attended in order to identify its variations and possible relations with the clinical review, disease, breed, age and sex. The STT-1 was accomplished in both eyes in dogs over two years old, females or males. Of these, those whose complaint included ocular clinical signs or those with previously identified ocular disease were excluded from this study. After analysis it were computed 92 dogs (194 eyes), 34 males and 58 females with 7,79 ± 3,7 e 7,76 ± 3,7 years old, respectively. About the breeds, 40,2% were mixed breed, 13,0% Poodle, 6,5% Shih-tzu and Basset Hound and 5,4% Pitbull. STT-1 <10mm/min was observed bilaterally in 4,3% of the dogs with mean age 7,4 ± 3,9 years old. Of these, 75% females and 25% males. STT-1 ? 10 e ? 14 mm/min was observed in 3,2% of the dogs, of these, 66,7% males and 33,3% females, 66,7% mixed breed and 33,3% Teckel. The mean age was 7,6 ± 3,8 years old. About the systemic diseases observed in the animals with STT-1 <10mm/min it were found reproductive apparatus changes(42,8%). It is emphasized the STT-1 in the clinical-surgical veterinary attendance even when the main complaint does not relate the ocular system, mainly in patients over seven years old

Diagnosis, Prognosis and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors

Mast cell tumors (MCTs) are hematopoietic neoplasms composed of mast cells. It is highly common in dogs and is extremely important in the veterinary oncology field. It represents the third most common tumor subtype, and is the most common malignant skin tumor in dogs, corresponding to 11% of skin cancer cases. The objective of this critical review was to present the report of the 2nd Consensus meeting on the Diagnosis, Prognosis, and Treatment of Canine Cutaneous and Subcutaneous Mast Cell Tumors, which was organized by the Brazilian Association of Veterinary Oncology (ABROVET) in August 2021. The most recent information on cutaneous and subcutaneous mast cell tumors in dogs is presented and discussed

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle