Hideki Kayanuma

Partial Anomalous Pulmonary Venous Connection in 2 Miniature Schnauzers

A 3-year-old, 6.0 kg, intact female Miniature Schnauzer was presented to Azabu University for evaluation of right heart enlargement, incidentally noticed on survey thoracic radiographs. The dog was asymptomatic and no abnormalities were identified on physical examination. Radiographic evaluation of the thorax indicated right heart enlargement (vertebral heart score, 12.1). Two-dimensional echocardiography disclosed right atrial and right ventricular dilatation (Fig 1). An abnormal vascular structure connected to the right atrium at the heart base was observed on color Doppler echocardiography (Fig 2). No other structural heart disease or conditions that could result in right heart dilatation (eg, pulmonary hypertension, atrial septal defect [ASD], tricuspid valve regurgitation) were found. A complete blood count (CBC) and serum biochemistry profile were within normal limits. D-dimer concentration (reference range, <0.2 lg/mL) was normal. Computed tomography angiography (CTA) and cardiac catheterization were performed under general anesthesia, maintained by fentanyl constant rate infusion and isoflurane inhalation, to determine a definitive diagnosis. A 4 Fr multipurpose catheter was introduced from the right jugular vein through a catheter introducer placed by the Seldinger technique. Oxygen saturation (SaO2) of each site within the heart was measured while breathing room air. Mean SaO2 of the cranial and caudal vena cava was 55.9%. SaO2 in the right atrium varied from 81.8 to 99.2%, depending on the location of the catheter tip. SaO2 at the right ventricle and pulmonary artery were 77.0 and 83.2%, respectively. Mean right atrial and pulmonary pressures were 1 and 11 mmHg, respectively. The dog was placed in dorsal recumbency on a clinical 16-multi-detector-row computed tomography scanner. Iodinated contrast medium (2 mg/kg) was rapidly injected via the cephalic vein. Repetitive transverse plane cine scans (120 kV, 99 mAs, 0.625 mm slice thickness, 0.6 s tube rotation time, 0.938 helical pitch) were acquired over the heart. Images were transferred to an image software system for further evaluation. Acquired images were analyzed using multiplanar reconstruction and volume rendering, and it was determined that the pulmonary vein of the right cranial lung lobe was connected to the right atrium. Therefore, a definitive diagnosis of partial anomalous pulmonary venous connection (PAPVC) was made (Fig 3).

Ultrasonographic evaluation of depth–width ratio (D/W) of benign and malignant mammary tumors in dogs

Depth-width ratio (D/W) is the only quantitative item in the criteria recommended by the Japanese Ultrasound Society for the evaluation of breast tumors in humans. However, the usefulness of the D/W has not been evaluated in dogs. Eighty-six mammary masses in 34 female dogs underwent ultrasonographic examination to determine the D/W and other characteristics. Results of ultrasonographic and histopathologic examinations were compared. The D/W of malignant tumors was significantly greater than that of benign tumors, and it had a sensitivity of 56.3% and a specificity of 92.9% for the diagnosis of malignancy when the threshold of D/W was 0.7. In addition, irregular margin, polymorphous shape and heterogeneous internal echographic characteristics were correlated with malignancy.

Disseminated nontuberculous mycobacterial disease in a cat caused by Mycobacterium sp. strain MFM001

Mycobacterium sp. strain MFM001 (MFM001), a new strain of slow-growing nontuberculous mycobacteria not associated with the Mycobacterium avium complex, led to disseminated mycobacterial disease characterized by transmural granulomatous gastroenterocolitis of lepromatous type in a cat treated with immunosuppressive medication. MFM001 was found to be closely related to M. kyorinense or M. celatum by partial sequence of 16S rDNA, and identical with an unspecified M. sp. strain B10-07.09.0206 isolated from a human pulmonary infection in Germany. MFM001 should be considered as a pathogenic organism in cats, especially in immunocompromised animals.

Hepatic AA amyloidosis in a cat: cytologic and histologic identification of AA amyloid in macrophages

A 3-year-old, spayed female, Domestic Shorthair cat presented with anorexia, lethargy, vomiting, probable hemoabdomen, and multiple masses on the right lateral liver lobe. Clinicopathologic and imaging abnormalities included anemia, azotemia, icterus, and hepatomegaly with hypoechoic masses. On cytologic evaluation of a fine-needle aspiration of a liver mass there was abundant extracellular pink- to purple-colored material between hepatocytes. The amorphous material was stained with direct fast scarlet (DFS), and green birefringent areas were observed under polarized light, confirming the presence of amyloid. A unique finding on the cytologic smear were macrophages containing amorphous and fibrillar amyloid-like protein. Histopathologic examination using H&E and Congo red staining confirmed amyloid deposits within the space of Disse, along the sinusoids, portal tracts, blood vessel walls, and within the cytoplasm of macrophages. Immunohistochemical staining with anti-AA amyloid antibodies further confirmed the presence of AA amyloid. To the authors knowledge, this is the first report of the cytologic finding of AA amyloid protein within macrophages and DFS stain detection of amyloid on a cytologic smear.

Primary Lung Carcinoma with Paraneoplastic Leukocytosis in a Dog

In human lung cancers, marked leukocytosis, especially with neutrophilia and monocytosis, has been reported as a paraneoplastic syndrome. In dogs, several reports have been published on paraneoplastic leukocytosis. In this case, various examinations were conducted on a dog with extreme neutrophilic leukocytosis diagnosed via a blood test at first admission. A huge pulmonary mass was detected, which was surgically removed. The tumor was diagnosed as papillary adenocarcinoma of the lung by histopathology. The number of neutrophils recovered to normal after surgery, and the dog was diagnosed as paraneoplastic syndrome due to lung cancer. Key word:dog, leukocytosis, lung cancer, paraneoplastic syndrome 1)Sato Animal Hospital, 1-14 Miyashitachou, Ichinoseki, Iwate 021-0013, Japan 2)School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5201, Japan 3)Veterinary Teaching Hospital, Azabu University, 1-17-71 Fuchinobe, Chuo, Sagamihara, Kanagawa 252-5201, Japan 4)Yamada Animal Hospital, 2-1, Koorikitanomachi, Neyagawa, Osaka 572-0080, Japan Corresponding author:Takuo Shida Telephone:042-754-7111 Facsimile:042-769-2418 Email address:shida@azabu-u.ac.jp Received:May 27, 2012 / Accepted:September 12, 2012 Note J Jpn Vet Cancer Soc, 3(2) −21− were all within normal ranges. According to these results, we surmised that the elevated BUN level was prerenal secondary to cardiac insufficiency. Based on these clinical data, the cause of the cough and the neutrophilia were considered to possibly be related to the thoracic mass. In order to improve the cough, thoracotomy was performed. The patient underwent surgery through the intercostal approach on the 15th day after first admission. The 5th rib of the patient was removed due to the large size of the mass. The mass involved the left caudal lung lobe and adhered to the pleura of the mediastinum and diaphragm. The pericardium was not involved in the mass. Blunt dissection of the mass from the pleura of the mediastinum caused some bleeding. After blunt dissection from the adhered sites, the left lung lobe was totally removed with the mass. Swelling of the tracheobronchial lymph nodes was not observed. The patient recovered from surgery without any events and showed good healthy conditions. The WBC count decreased to the normal range 2 weeks after surgery(Table 3)and was normal for 21 weeks after surgery. The patient’s cough disappeared after surgery, and the respiratory function of the patient was recovered. Furthermore, cardiac function was maintained well with the simultaneous administration of digoxin and an angiotensin converting enzyme inhibitor for cardiac insufficiency. However, cardiac function worsened, and 4 months after surgery, the patient had an increased BUN level. The patient showed collapse/syncope due to cardiac failure and died 5 months after surgery. Autopsy was not permitted by the client. Histopathological examination of the pulmonary mass revealed that the tissue consisted of multiple neoplastic foci divided by various amounts of fibrous septa. The neoplastic foci were characterized by papillary or glandular structures that were lined by cuboid to cylindroid epithelial cells. Some tumor cells showed a goblet-cell appearance, while some had cilia on their cell surface. These proliferating neoplastic cells showed moderate cellular atypia, and the mitotic figure index was 2-3 per high-power magnification(×400)field. The tumor cells invaded the lymph vessels of the surrounding tissues. Multifocal necrotic areas were also observed within the neoplastic foci. In the interstitial areas, there were moderate infiltrations of lymphocytes and macrophages, deposition of calcium, and occasional ossification. The pleurae were Fig. 1.Thoracic radiography(ventrodorsal view)revealed a large mass in the left caudal lung area that compressed and shifted the enlarged heart to the right. Fig. 2.Numerous neutrophils were observed in the blood smear specimen (×100).