NODULAR FAT NECROSIS IN THE FELINE AND CANINE ABDOMEN

The radiographic appearance of nodular fat necrosis is described in ten cats and one dog. The most common radiographic sign was the presence of a focal mineralized circular to oval soft tissue mass in the abdominal fat as present in 9 cats. These masses had a distinct eggshell-like rim encapsulating the lesion. In one cat and one dog multiple masses were present, without radiographic signs of mineralization. Abdominal ultrasound was performed in three cats and one dog, findings included the presence of hyperechoic masses with associated acoustic shadowing, some with a hypoechoic centre. Almost all animals were old and obese. In three cats and one dog, changes were confirmed with biopsy or post mortem examination. Lesions having the appearance of those in this paper are most likely incidental findings and should not be confused with abdominal masses of neoplastic origin. Ultrasound can be helpful in identifying such lesions.     

A RETROSPECTIVE STUDY ON THE SONOGRAPHIC FINDINGS OF ABDOMINAL CARCINOMATOSIS IN 14 CATS

A retrospective review was performed on 14 cats with histology- or cytology-proven carcinomatosis. The mean age was 12.7 years with a median of 11 years. The diagnosis of carcinomatosis was made by histology in 11 cats and cytology in three cats. Twelve cats had cytologic examination of the peritoneal free fluid and seven cats (58.3%) had evidence of malignant cells. The primary tumor site was determined in 13 cats. The most common organ locations for the primary tumor were the liver (n = 5), pancreas (n = 3), and small intestine (n = 3). Other sites were stomach and spleen in one cat each. Epithelial cell neoplasia was the primary tumor type in 11 cats. Two cats had abdominal lymphomatosis and one cat had abdominal sarcomatosis secondary to metastatic hemangiosarcoma. Free peritoneal fluid and masses in the connecting peritoneum were found in all cats (100%). Additional findings included primary or metastatic masses in abdominal organs in 10 cats (71.4%), lymph node enlargement in five cats (35.7%), pleural effusion in three cats (21.4%), parietal peritoneal masses in two cats (14.3%), and visceral peritoneal masses in one cat (7.1%). Masses in the connecting peritoneal may be a very specific finding for carcinomatosis in cats, especially with a concurrent abdominal neoplastic mass. Parietal and visceral peritoneal masses, while uncommon in this series of cats, have not been reported for other diseases and seem to strongly support a diagnosis of carcinomatosis.     

Fatal placental subinvolution in a captive capybara (Hydrochaeris hydrochaeris, Order Rodentia)

An adult, captive-born female capybara died of systemic thrombosis and hemoperitoneum associated with placental subinvolution. Grossly, the uterus was enlarged, segmentally thickened, and associated with a large blood clot in the abdominal cavity. There was hemometra and a large ovoid mass in each uterine horn weakly adhered to the endometrium, and the right uterine horn wall had a small perforation over the mass. The mesometrial veins were markedly dilated due to thrombosis and occasionally perforated. Histologically, the uterine masses consisted of partly necrotic placental and subplacental tissue. The uterine wall surrounding the masses had full-thickness coagulative necrosis of the myometrium and diffuse endometrial ulceration with abundant syncytiotrophoblast-like cells within capillaries. Vascular lesions in the uterus and mesometrium consisted of mural invasion by cytotrophoblast and syncytiotrophoblast-like cells, thrombosis, fibrinoid necrosis, and/or heterophilic vasculitis. This is the first report of placental subinvolution in capybaras or any rodent species, to the authors' knowledge.     

Uterine myxoid leiomyosarcoma with widespread metastases in a cat

A 10-year-old domestic shorthair cat was spayed to remove bilateral ovarian masses and an enlarged uterus. Both ovaries were effaced by large, irregular, firm, glistening, white cystic masses filled with clear viscous fluid. The uterine lumen was filled with copious amounts of clear viscous fluid, and the uterus contained multiple, firm, glistening, white nodules. Histologic examination revealed an invasive spindle cell neoplasm with features of malignancy, and extensive hypocellular areas containing an alcian blue-positive myxoid matrix. Tumor cells expressed caldesmon, alpha-smooth muscle actin, and estrogen receptor but were negative for desmin. The animal was euthanized 1 month later because of suspected local tumor recurrence. At necropsy, the abdominal cavity contained 120 ml of mucoid ascites; multiple tumor nodules were present in the abdominal and thoracic cavities. The clinical behavior and gross, microscopic, and immunohistochemical findings established a diagnosis of myxoid leiomyosarcoma.     

Large granular lymphoma in an FIV-positive and FeLV-negative cat

The clinical course of a feline leukaemia virus (FeLV)-negative and feline immunodeficiency virus (FIV)-positive cat affected with a large granular lymphocyte lymphoma is presented. Cyto-logical examination showed neoplastic cells in the pleural effusion and in two abdominal masses. Bone marrow and peripheral blood were moderately involved and chemotherapy was used to control the tumour. Cytochemistry, immunohis-tochemistry and ultrastructural studies were applied to define the cellular lineage; cytochemistry suggested a T-cell lineage.     

Teratocarcinoma of the ovary in a mare

A 5-year-old Appaloosa mare had a history of mild intermittent abdominal discomfort and clinical signs that were suggestive of intestinal obstruction. Palpation per rectum revealed a large mass attached to the left uterine horn, with smaller masses extending dorsally and cranially and causing constriction of the rectum. At necropsy, numerous multilobulated masses were observed in the abdominal cavity and several nodules were seen in the lungs. The left ovary was large and contained both cartilage and hairlike material. Sections from all masses had similar histologic features and confirmed the tentative diagnosis of teratocarcinoma.     

Bilateral uveal metastasis of a subcutaneous fibrosarcoma in a cat

A 6‐year‐old neutered male domestic short‐haired cat was presented to the Comparative Ophthalmology service at Michigan State University with a 3‐week history of decreased appetite and redness of the left eye. The left forelimb had been removed 15 months previously because of the presence of a subcutaneous fibrosarcoma. In the left globe, a large iridal mass was associated with increased intraocular pressure and retinal detachment. A smaller mass involving the right iris was also present. Imaging revealed a 2‐cm mass in the left caudodorsal lung lobe, and abdominal ultrasound showed multifocal bilateral renal masses. Aspirates of these masses were nondiagnostic. The left globe was removed for palliative reasons, and histopathology showed that fibrosarcoma was infiltrating the iris, choroid, and optic nerve. Despite systemic chemotherapy with doxorubicin, the animal died 4 months after initial presentation. Histopathology confirmed highly angioinvasive metastatic fibrosarcoma also in the right uveal tract, the lungs, and both kidneys.     

Lymphangiosarcomas in cats: a retrospective study of 12 cases

Clinical, macroscopic, and histologic features of 12 lymphangiosarcomas in cats are described. Nine tumors were located in the subcutaneous tissue at the caudoventral abdominal wall (eight cats) or in the neck (one cat). The remaining three cats had lymphangiosarcomas around the cranial mesenteric artery (two cats) or precardial in the mediastinum (one cat). Macroscopically, the tumors were noncircumscribed, white, edematous, and intermixed with fat tissue. Histologic features varied from cleft-forming and cavernous growth to papilliform and solid patterns. Follow-up data were available for seven cats with subcutaneous lymphangiosarcomas. All these cats died or were euthanatized within 6 months after surgery because of poor wound healing, local recurrence, or distant metastases. The cats with abdominal or thoracic masses were either euthanatized at surgery or within 6 months after the first surgery because of recurrent chylothorax, chyloperitoneum, or distant metastases.     

Lymphoma involving large granular lymphocytes in cats: 11 cases (1982-1991).

Medical records of 11 cats with lymphoma involving large granular lymphocytes were reviewed. All 9 cats tested were FeLV-negative. Ten cats had a history of anorexia, lethargy, vomiting, or diarrhea, and had lymphoma involving abdominal viscera. The most common site of tumor in these cats was the jejunum. One cat had cutaneous masses caused by dermal and epidermal infiltration with neoplastic large granular lymphocytes. The most common hematologic abnormality was leukocytosis, characterized by neutrophilia with a left shift (7 cats); 2 cats had a left shift without neutrophilia. None of the cats had lymphocytosis, but immature large granular lymphocytes were found in the blood of 4 cats. The most common serum biochemical abnormalities were hypoalbuminemia (10 cats), hypocalcemia (10 cats), hypoproteinemia (9 cats), high aspartate transaminase activity (9 cats), and hyperbilirubinemia (8 cats). Large granular lymphocytes were characterized by abundant cytoplasm containing distinct azurophilic granules that varied in size and number. The most common cytochemical staining pattern included detection of alpha-naphthyl butyrate esterase, acid phosphatase, and beta-glucuronidase activities. On examination of histologic sections, granules stained weakly eosinophilic with Giemsa and moderately with periodic acid-Schiff reaction. Ultrastructurally, the granules appeared membrane bound and contained an electron-dense matrix in 4 cats.     

Diagnostic ultrasonography in cattle with abdominal fat necrosis

This study describes the ultrasonographic findings in 14 cows with abdominal fat necrosis. Ultrasonography of the abdomen revealed the presence of heterogeneous hyperechoic masses and hyperechoic omentum with localized masses floating in a hypoechoic peritoneal fluid. A hyperechogenic rim was imaged around both kidneys. The intestines were coated with hyperechoic capsules and the intestinal lumens were constricted. Ultrasonographic examination of the pancreatic parenchyma showed an overall increased echogenicity which was homogenously distributed in 3 cases. A diagnosis of abdominal fat necrosis was made with ultrasound-guided biopsy of the echogenic masses, and thereafter at postmortem examination. Results from this study demonstrate the efficacy of ultrasonography as an imaging modality for antemortem diagnosis of abdominal lipomatosis in cattle. To the authors' knowledge, this study is the first that illustrates ultrasonographic findings in cattle affected with abdominal lipomatosis.     

Fibrosarcoma with sarcomatosis and metastasis in a FeLV-negative cat

A 6-year-old, spayed female, mixed shorthair cat presented to the emergency service at The Ohio State University Veterinary Medical Center for evaluation of hypercalcemia, a right eye mass, and multiple intrathoracic and intra-abdominal masses. Cytologic evaluation of one of the abdominal masses revealed a uniform population of large, anaplastic mesenchymal cells found individually, in loose aggregates, and occasionally associated with pink, extracellular matrix. The cytology was consistent with a malignant mesenchymal neoplasm, with primary consideration given to fibrosarcoma and hemangiosarcoma. The cat was euthanized and histopathology confirmed disseminated fibrosarcoma. Fibrosarcoma comprises 12%-41% of feline cutaneous tumors and affects cats at a mean age of 9.6 years. Three manifestations of fibrosarcoma predominate in cats: spontaneous solitary fibrosarcoma, vaccine-induced/injection site fibrosarcoma, and oncogene-induced (FSV) fibrosarcoma. The history, signalment, and results from diagnostics performed did not support solitary fibrosarcoma or injection-induced sarcoma. Although some criteria fit with virally induced fibrosarcoma, such as age and the presence of multiple fibrosarcomas, the neoplastic population was negative for FeLV IHC. The presence of fibrosarcomas throughout the pleural and peritoneal cavity was most compatible with sarcomatosis and the distant metastasis of an unidentified primary neoplasm. To the authors’ knowledge, this is the first reported case of sarcomatosis in a FeLV-negative cat.     

ASSOCIATIONS BETWEEN DUAL‐PHASE COMPUTED TOMOGRAPHY FEATURES AND HISTOPATHOLOGIC DIAGNOSES IN 52 DOGS WITH HEPATIC OR SPLENIC MASSES

Ability to noninvasively differentiate malignant from nonmalignant abdominal masses would aid clinical decision making. The aim of this retrospective, cross‐sectional study was to identify features in dual‐phase computed tomographic (CT) studies that could be used to distinguish malignant from nonmalignant hepatic and splenic masses in dogs. Medical records were searched for dogs that had an abdominal dual‐phase CT examination, a hepatic or splenic mass, and subsequent histopathologic diagnosis. Computed tomographic images for all included dogs were acquired prior to and <30 s (early phase) and >60 s (delayed phase) after intravenous contrast administration. Fifty‐two dogs with 55 masses were studied: 24 hepatic, including 14 (58%) malignant and 10 (42%) non‐malignant; 31 splenic, including 18 (58%) malignant and 13 (42%) nonmalignant. There was substantial overlap in the pre‐ and postcontrast CT features of malignant and nonmalignant hepatic and splenic masses. Regardless of histologic diagnosis, hepatic masses most frequently showed marked, generalized enhancement in early phase images that persisted in the delayed phase. Splenic hemangiosarcoma and nodular hyperplastic lesions most frequently showed marked, generalized enhancement in early phase images that persisted in delayed images whereas most splenic hematomas had slight enhancement in early phase images. All splenic hematomas and 77% of the hemangiosarcomas had contrast accumulation compatible with active hemorrhage. There were no other significant differences in quantitative or categorical CT data between malignant and nonmalignant hepatic or splenic masses. Dual‐phase CT of dogs with hepatic or splenic masses provides limited specific diagnostic information.     

Uterine adenocarcinoma with abdominal metastases in an ovariohysterectomised cat

SURGICAL FINDINGS: an adenocarcinoma of the uterine stump with abdominal metastases is described in a 12.5-year-old incompletely ovariohysterectomised domestic shorthair cat. At the time of presentation, the adenocarcinoma had metastasised to the right perirenal lymph node, the abdominal aorta and the right ureter, resulting in the formation of a large cystic structure. This had compressed and displaced surrounding structures, including the abdominal vena cava and the right kidney, and formed multiple adhesions to the body wall and adjacent abdominal structures. Metastatic extension to the aorta had resulted in its regression into a 2 mm diameter non-pulsatile vessel. PRACTICAL RELEVANCE: only one case of uterine adenocarcinoma has previously been reported in an ovariohysterectomised cat. As such, this represents a very unusual and severe complication following an incomplete ovariohysterectomy. Invasion of the tumour tissue into surrounding structures created further complications.     

Systemic Exophiala jeanselmei infection in a cat

A 14-year-old spayed domestic shorthair cat was referred for ultrasonographic evaluation of abnormally shaped kidneys. Multifocal lesions were detected ultrasonographically in the liver and kidneys; a fine-needle aspirate of the kidneys was performed, and numerous clumps of fungal hyphae were identified. The following day, the cat was recumbent with advanced neurologic signs. The cat was euthanatized, and a necropsy was performed. Multifocal granuloma-like masses were seen on the liver, kidneys, abdominal wall, mesentery, thoracic wall, pericardium, and epicardium. Similar lesions were found on the cervical portion of the spinal cord, the cerebrum, and cerebellum. Exophiala jeanselmei, an organism of the phaeohyphomycotic group, was identified on fungal culture. To our knowledge, systemic infections caused by this organism have not been reported. However, phaeohyphomycotic infections are believed to be an emerging disease in humans.     

一例猫卵巢恶性颗粒细胞瘤的病理学分析

本文报道猫伴发腹腔种植性转移的卵巢恶性颗粒细胞瘤1例,较为罕见,国内外文献未见报道。1例15岁雌性家猫,因不食和腹围增大就诊。超声检查显示,左肾尾侧可见一大小约4.27 cm×2.63 cm的肿物。开腹探查,可见大网膜、肠壁及胃壁弥散性分布大量大小不等的球形肿物,左侧卵巢明显增大,表面形成坚实或柔软的结节。对肿物进行组织病理学检查,诊断为卵巢恶性颗粒细胞瘤。本文提供该病例临床和组织病理学资料,并回顾相关文献资料,希望对该肿瘤的诊疗和研究提供帮助。     

Renal transitional-cell carcinoma in two cats with chronic kidney disease

Two 12-year-old cats were diagnosed with chronic kidney disease (CKD) based on physical examination, clinicopathologic data and, in one case, abdominal ultrasound findings. Approximately 1 year after the initial diagnosis of CKD both cats developed renal transitional cell carcinoma (TCC)--bilateral in one cat. Based on post-mortem examination, one cat had no evidence of metastasis and the other had metastasis to the large intestine, heart and lungs. This is the first report of de novo bilateral renal TCC in a cat, as well as the first report of renal TCC developing in cats with previous history of confirmed CKD.     

Gastrointestinal pythiosis in two cats.

Two young adult male Domestic Shorthair cats living in the southeastern United States were evaluated for signs attributable to partial intestinal obstruction. Physical examination indicated a palpable abdominal mass in each animal. Exploratory laparotomy revealed a large extraluminal mass involving the ileum and mesentery with adjacent mesenteric lymphadenopathy in cat No. 1 and an abscessed mass in the distal duodenum in cat No. 2. Mass resection and intestinal anastomosis were performed in both cats. Histologic evaluation indicated that the intestinal lesions involved primarily the outer smooth muscle layer and serosa and consisted of eosinophilic granulomatous inflammation with multifocal areas of necrosis. In Gomori methenamine silver-stained sections, broad (2.5-7.5 microm), occasionally branching, infrequently septate hyphae were observed within areas of necrosis. A diagnosis of Pythium insidiosum infection was confirmed in both cats by immunoblot serology and by immunoperoxidase staining of tissue sections using a P. insidiosum-specific polyclonal antibody. Cat No. 1 was clinically normal for 4 months after surgery but then died unexpectedly from an unknown cause. Cat No. 2 has been clinically normal for at least 9 months after surgery and appears to be cured on the basis of follow-up enzyme-linked immunosorbent assay serology.     

Generalized nodular dermatofibrosis in the absence of renal neoplasia in an Australian Cattle Dog

A 13-year-old, spayed, female Australian Cattle Dog had at least a 10-year history of numerous subcutaneous nodules for which fine-needle aspiration and cytologic evaluation were nondiagnostic. Abdominal ultrasound 3.5 months before necropsy detected a small left kidney but no cysts or neoplasms. At gross necropsy, innumerable, firm, round to oval, white, 0.25 to 2 cm masses were detected throughout the subcutaneous tissues of the axial and appendicular skeleton, epimysium of numerous muscles, and parietal peritoneum of the lateral abdominal body wall. The left kidney was approximately half the size of the right, and there was severe bilateral renal medullary (papillary) necrosis. Histologically, the subcutaneous nodules were well-demarcated masses of mature, hypocellular collagen that were consistent with previous reports of nodular dermatofibrosis and renal cystadenomas or cystadenocarcinomas. In addition to diffuse acute medullary necrosis, both kidneys were affected by severe chronic lymphoplasmacytic interstitial nephritis. This is the first known report of nodular dermatofibrosis in a dog without renal cysts, cystadenoma, or cystadenocarcinoma.     

Vaginal leiomyofibromatosis and goiter in a goat

A mature nulliparous Saanen-type goat examined for episodes of vulvar hemorrhage had coalescing nodular vaginal masses. The histopathologic diagnosis from a biopsy specimen was leiomyofibromatosis. Because of the relationship of these tumors in bitches to cystic ovaries and the nonrecurrence in bitches after excision and ovariectomy, abdominal exploration was performed. Bilaterally cystic ovaries were removed, and the vaginal tumors slowly regressed over the subsequent year, although transvaginal adhesions formed because of the extensive superficial necrosis originally present.     

A Rare Case of Polyorchidism in a Cat with Four Intra‐abdominal Testes

Polyorchidism is a rare congenital anomaly defined as the presence of more than two histologically proven testes. We report a case of a 9‐month‐old European cat with four intra‐abdominal testes. The diagnosis was performed by means of ultrasonography, intra‐operative examination and histological confirmation. The case reported here presents an extremely rare anomaly, as no previous studies in veterinary medicine have reported the presence of four testes. This case suggests that supernumerary testes should be included as differential diagnoses for intra‐abdominal masses.