COMPUTED TOMOGRAPHY DIAGNOSIS OF ISOLATED SPLENIC TORSION IN A DOG

Isolated splenic torsion in a dog was diagnosed using computed tomography (CT). The enlarged non enhanced spleen and a twisted soft tissue mass effect represented the rotated pedicle were the main findings. Abdominal radiography and ultrasonography were not conclusive.     

Chronic primary splenic torsion with peritoneal adhesions in a dog: case report and literature review

Primary splenic torsion in dogs is uncommon and can occur in acute or chronic form. The chronic form is difficult to diagnose because the clinical signs are vague and sometimes intermittent. A dog with a history of diaphragmatic hernia repair two years previously presented with chronic, vague clinical signs and an abdominal mass. The mass was revealed to be spleen on ultrasonography. On exploratory laparotomy, the dog was found to have a splenic torsion of approximately 180 degrees with mature, fibrous adhesions retaining the spleen in a torsed position. A splenectomy was performed, and the dog recovered uneventfully with complete resolution of prior clinical signs. Prognosis for dogs with splenic torsion is good, although complications are relatively common.     

MRI findings of a middle ear cholesteatoma in a dog

This article describes the MRI features of a middle ear cholesteatoma in an 8 yr old flat-coated retriever. Physical examination revealed pain on opening the jaw, and otoscopic examination showed tympanic membrane rupture associated with hyperplastic tissue at the entrance of the middle ear. Standard MRI sequences allowed for the identification of a severely expanded bulla containing material that was isointense to brain tissue on T1-weighted images and of mixed intensity on T2-weighted and fluid-attenuated inversion recovery sequences. No postcontrast enhancement of the content was present, but the lining of the bulla was partially enhanced. The images allowed evaluation of the surgical margins and the secondary changes due to the expansion of the mass. Surgery was performed and histopathology confirmed the presumptive diagnosis of cholesteatoma. In the present case, MRI appeared to serve as a good alternative to computed tomography for the diagnosis of cholesteatoma.     

Intrapancreatic accessory spleen mimicking pancreatic insulinoma with intrapancreatic metastasis in a cat

An 11-year-old neutered male Domestic Shorthair cat presented with a 3-month history of hypoglycemia, two episodes of seizure, and intermittent tick-like signs. Serum biochemistry revealed severe hypoglycemia associated with high insulin concentrations. Dynamic abdominal computed tomography (CT) indicated two pancreatic masses, which were enhanced most during the late arterial phase but had different degrees and variations of attenuation. Partial pancreatectomy was performed. Histopathology and immunohistochemistry confirmed that one mass was an insulinoma and the other was an ectopic splenic tissue, consistent with the differences in imaging findings. When an intrapancreatic lesion with hyper-attenuation on dynamic abdominal CT is detected, not only insulinoma or metastasis of malignancies but also intrapancreatic accessory spleen (IPAS) should be considered as differential diagnoses.     

Spleen cell population changes and hemolytic anemia in F344 rats with large granular lymphocyte leukemia

A spontaneous large granular lymphocyte leukemia from a F344 rat was transplanted to 36 syngeneic recipients to study the interactions among leukemia, T lymphocytes, and the development of immunemediated hemolytic anemia. Six rats were euthanatized at biweekly intervals, and spleen weight, total spleen cellularity, and differential spleen cell counts were correlated with hemograms and osmotic fragility. Sequential changes in splenic architecture were correlated with hematologic parameters. Monoclonal antibodies defining all T lymphocytes (W3/13), T helper-inducer cells (W3/25), and T suppressor cells (OX-8) were used to identify T cells in immunocytochemical techniques on spleen sections, as well as in fluorescence activated cell sorter analysis of spleen cell suspensions. The onset of hemolytic anemic at 7 weeks after transplantation coincided with the first detection of tumor cells in the spleen and peripheral blood. Tumor cells first accumulated in the marginal zones, and then they infiltrated the red pulp sinusoids. Although the leukemia caused dispersion of the splenic lymphoid tissue, there was no significant lymphopenia, and the relative number of helper (W3/25+) and suppressor (OX-8+) lymphocytes did not change. Because the induction of anemia was a relatively early event in splenic involvement, we concluded that anemia was unrelated to disruption of lymphoid architecture; furthermore, it does not appear to be caused by changes in the numbers of regulatory T lymphocytes.     

Laparoscopic Splenectomy for Treatment of Splenic Hemangiosarcoma in a Dog

Objective: To report laparoscopic splenectomy in a dog. Study Design: Clinical report. Animals: Mixed breed dog (n=1). Methods: Hemangiosarcoma was diagnosed by ultrasound‐guided fine‐needle aspiration of a splenic mass in an 11‐year‐old, 30 kg, mixed breed dog. No metastatic disease was identified during complete staging (chest radiographs, echocardiogram, and abdominal ultrasonography); however, cystic calculi were identified. Laparoscopic splenectomy using Ligasure V was performed through 3 portals and the calculi were removed by laparoscopic‐assisted cystoscopy. Results: Total surgical time was 2 hours and for laparoscopic splenectomy, 65 minutes. The celiotomy incision for splenic removal was 7 cm. The dog recovered uneventfully and was ambulatory 2 hours postoperatively. Conclusion: Laparoscopy with Ligasure V facilitated successful removal of a spleen with a 3 cm mass. Clinical Relevance: Laparoscopic splenectomy in dogs is feasible for removal of a normal‐sized spleen with a moderate‐sized mass.     

Successful derotation of a splenic torsion in a racing greyhound

A two-year-old male racing greyhound was presented to the Sydney University Veterinary Hospital with a six-week history of intermittent gastric dilatation. Abdominal radiography and ultrasonography were suggestive of splenic torsion without gastric dilatation. Exploratory ceoliotomy confirmed a 540° clockwise rotation of the spleen. Derotation of the spleen was performed and thrombosis was not present in the splenic vessels. Epinephrine was injected into the splenic parenchyma to aid in splenic contraction. The spleen was left in situ. The greyhound made an uneventful recovery and has won several races in the 10-month follow-up period without further problems.     

Computed tomography and magnetic resonance imaging of thoracic chordoma in a Bengal tiger (Panthera tigris tigris)

A Bengal tiger was presented for evaluation of weakness, ataxia and inappetance. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass extending from the T7-8 vertebral body to the left rib and compressing the spinal cord. On CT, the bone destruction and sequestrum were shown. On MRI, the multilobulated mass appeared hypo- to isointense in T1-weighted and hyperintense in T2-weighted images. The tiger died after imaging, most likely from renal failure. Chordoma without metastasis was diagnosed on necropsy. The imaging characteristics were similar to those found in chordoma in humans. This report describes the use of CT and MRI in an exotic species.     

IMAGING DIAGNOSIS—FDG‐PET/CT OF A CANINE SPLENIC PLASMA CELL TUMOR

An 8‐year‐old Shih Tzu developed abdominal pain and hyperglobulinemia. A round splenic mass was noted radiographically and sonographically. The patient was evaluated by fluorodeoxyglucose positron emission tomography coupled with computed tomography (FDG‐PET/CT). There was no evidence of metastasis or bone marrow involvement on PET/CT images. The standardized uptake value (SUV) of the splenic mass was increased over the reference range (SUV=4.83). The patient was diagnosed as splenic extramedullary plasmacytoma through immunohistopathologic study. After the splenectomy, the globulin level normalized and the patient is alive without complications.     

Usefulness of MRI compared with CT for diagnosis of mesenteric lymphoma in a dog

We evaluated the usefulness of MRI and compared it with CT for diagnosis of mesenteric lymphoma in a dog. The results in the plain CT, dynamic CT and plain MR (T1WI and T2WI) images suggested that the mass was a large single nodular lesion with abundant blood perfusion. On enhanced MRI(T1WI) , the mass was depicted as a tumor with adhesion to the gut wall. Exploratory laparotomy confirmed the mass was consistent with the findings on enhanced MRI. We think that MRI might be a useful imaging tool for diagnosis of canine mesenteric lymphoma.     

Abdominal CT evaluation of the liver and spleen for staging mast cell tumors in dogs yields nonspecific results

Canine mast cell tumor staging is commonly performed using abdominal ultrasonography and fine‐needle aspiration cytology of masses, lymph nodes, and hepatic and splenic parenchyma. Computed tomography is used for abdominal, thoracic, or whole body imaging in staging mast cell tumors in the authors’ institution enabling evaluation of multiple body areas in one examination. The aim of this study was to compare the CT examinations acquired for staging of mast cell disease to their subsequent liver and spleen cytology findings. Medical records of dogs with primary mast cell tumors that underwent abdominal CT and concurrent liver and spleen aspirates were reviewed. The CT examinations were evaluated for attenuation, size, and margination of the liver and spleen. The relationship between CT findings and cytology results was analyzed. Forty‐nine dogs matched the inclusion criteria: five of forty‐nine dogs with cutaneous mast cell tumors were positive for metastasis from liver and/or spleen aspirates. Of the five dogs with cytological evidence of liver or spleen metastasis, four had normal CT liver attenuation and size, one dog had concurrent primary hepatocellular neoplasia, four dogs had abnormal splenic parenchyma (two nodular and two diffuse heterogeneity), and one dog had a normal attenuation of the spleen. In four dogs, the spleen was subjectively enlarged. Computed tomographic evaluation of the liver showed no consistent pattern associated with mast cell metastasis and did not predict cytology results. Multifocal splenic hypoattenuating lesions more commonly coincided with mast cell metastasis. Sampling of the liver and spleen remains to be considered in the absence of abnormal CT findings for full staging.     

Magnetic resonance imaging of focal splenic and hepatic lesions in the dog

Focal hepatic and splenic lesions in the dog are common, and approximately half of such lesions are malignant. Both incidentally discovered lesions and lesions in patients with known malignancies represent diagnostic dilemmas. Ultrasound often fails to characterize such lesions adequately. This uncertainty may result in unnecessary splenectomies and liver biopsies for benign lesions or noncurative surgery for advanced-stage malignancies. In humans, ultrasound largely has been supplanted by computed tomography and magnetic resonance imaging (MRI) for the characterization of focal hepatic and splenic lesions. The inherently high soft tissue contrast of MRI allows the differentiation of benign from malignant hepatic and splenic lesions in the human patients. In this prospective study, 35 focal lesions of either the spleen (n = 8) or the liver (n = 27) were characterized by MRI in 23 dogs. Lesions were presumptively classified as malignant or benign on the basis of MRI findings. Imaging results then were correlated with histopathologic (29) or cytologic (6) evaluation of the lesions. The overall accuracy in differentiating malignant from benign lesions was 94% (33 of 35 lesions). The overall sensitivity and specificity were 100% (95% CI, 78-100%) and 90% (95% CI, 68-99%), respectively. MRI classified malignant hepatic lesions as hepatocellular carcinoma (HCC) in all confirmed cases and correctly predicted the histologic grade of 5 HCC lesions. These results suggest that MRI is a useful modality for abdominal imaging in veterinary patients, and MRI accurately differentiated benign from malignant focal hepatic and splenic lesions in this sample of patients.     

Diagnosis and surgical treatment of a primary splenic torsion in a domestic ferret (Mustela putorius furo)

A 4-year-old female spayed domestic ferret (Mustela putorius furo) presented with a history of vomiting over 24 hours. On physical examination, a significantly enlarged, firm spleen was palpated. Abdominal radiographs and abdominal ultrasound were suggestive of a splenic torsion or splenic infarction. An exploratory laparotomy confirmed the initial diagnosis and splenectomy was performed using a vessel sealing device. Histologic evaluation and culture of the spleen were consistent with primary torsion without evidence of infection or neoplasia. The patient recovered from surgery without complications. Based on a literature search, this is the first report of the clinical diagnosis and successful surgical treatment of a primary splenic torsion in a ferret. Although it appears to be a rare and potentially life-threatening disease in ferrets, splenic torsion should be considered as a differential diagnosis in ferrets that present with non-specific signs and a palpably enlarged spleen.     

SONOGRAPHIC AND RADIOGRAPHIC CHANGES ASSOCIATED WITH SPLENIC TORSION IN THE DOG

The clinical, radiographic, and sonographic signs in three dogs with splenic torsion are presented. AH dogs exhibited weight loss, anorexia, and lethargy. Splenomegaly was consistent radiographic finding in two dogs and large ill-defined midabdominal mass was seen in one dog. The spleen was easily imaged sonographically in all dogs. Splenic sonography in two dogs showed diffuse, hypoechoic pattern consistent with splenic congestion. Hilar splenic vessels were enlarged on the sonograms of two dogs.     

Anatomical variation of arterial supply to the rabbit spleen

The rabbit, which is widely used as an experimental animal and is also popular as a companion animal, has a flat and elongated spleen with the longitudinal hilus running along its visceral surface. The spleen receives via the hilus an arterial supply that is essential for splenic nutrition and normal functioning. However, the distribution and variation of the arteries to the spleen have not been studied in detail. This study investigated anatomical variations of splenic arterial supply in 33 New Zealand White rabbits with a colored latex injection into arteries. We also examined whether the length of the spleen correlated with the number of the splenic branches of the splenic artery. The splenic artery always arose as the first independent branch of the celiac artery and ran along the splenic hilus to usually provide 6 (range, 3 to 10) splenic branches to the spleen. There was a moderate correlation (R=0.6) between the number of splenic branches and the longitudinal length of the spleen. The splenic branches often arose as a trunk or trunks in common with short gastric arteries. The number of common trunk(s) was usually 1 (range, 0 to 4). The data showed that the pattern and number of arterial branches to the spleen varied according to the individual animal, suggesting that such variations should be considered when performing experimental and veterinary surgical treatments in rabbits.     

A primary extraskeletal osteogenic sarcoma arising in the spleen of a dog

This paper describes a primary extraskeletal osteogenic sarcoma arising in the spleen of an 11-year-old, male, cross-bred Terrier. Initial diagnosis was made after surgical removal of a splenic mass, at which time the liver and other abdominal viscera appeared grossly normal. However, elevations in the activities of alanine aminotransferase and alkaline phosphatase in blood taken 7 days after laparotomy suggested that hepatic metastases were developing. This was confirmed when the dog died 3.5 months after surgery, with massive hepatic metastatic involvement. There appears to be no previous report of the spleen being the primary site of such a neoplasm in the dog.     

IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG

A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen.     

Chronic splenic torsion in a dog with an accessory spleen

A 4-year-old, neutered male, mixed breed Old English sheepdog was presented for evaluation and treatment of anorexia, vomiting, and diarrhea. Presumptive severe pancreatitis was diagnosed based on the referral bloodwork. Abdominal ultrasonography identified a suspected liver lobe torsion based on the presence of a normal spleen. However, an exploratory laparotomy identified a splenic torsion in addition to a grossly normal spleen.Key clinical message:This case demonstrates that a second, potentially large area of splenic tissue (ectopic or accessory) can be present in the dog; therefore, the presence of a normal appearing spleen on abdominal ultrasonography does not rule out splenic torsion.     

Traumatic subcutaneous translocation of the spleen in an Old English sheepdog

A 14-month-old entire male Old English sheepdog was presented with a slowly enlarging subcutaneous soft tissue swelling caudal to the last rib. Radiographic and ultrasonographic Investigations demonstrated a soft tissue mass closely adherent to the body wall, with a coarse hypoechoic pattern. Surgical exploration revealed a mass with the gross appearance of splenic tissue. The mass was adhered to a healed paracostal abdominal tear. Histological examination confirmed the resected tissue to be normal spleen.     

High-resolution fluorodeoxyglucose positron emission tomography and magnetic resonance imaging findings of a pituitary microtumor in a dog

A 16-year-old, castrated, male English cocker spaniel dog was presented due to generalized alopecia. Routine clinical pathology, endocrine and abdominal ultrasonography results were consistent with a diagnosis of pituitary-dependent hyperadrenocorticism. The adenohypophyseal lesion was clearly visualized on both 3 T and 7 T magnetic resonance imaging (MRI) of the pituitary gland. Although biochemical and MRI findings were consistent with a functional pituitary microtumor, a pituitary lesion was not detected using ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET). This report firstly describes the application of high-resolution FDG-PET to a spontaneous pituitary microtumor in a dog.