Benign Fibrous Histiocytoma of Prepuce in the Mule

Here we present a case of preputial benign fibrous histiocytoma in a 7‐year‐old mule. This case was treated surgically. Pathologic analysis and diagnosis of these lesions were based on a combination of light microscopy and immunohistochemistry. Histologically, the tumour was composed primarily of a storiform pattern of fibroblastic and poligonal cells. In immunohistochemistry, except for consistent immunoreactivity for vimentin, nearly all tumour cells were positive for CD68, S‐100 protein, pan‐cytokeratin, alpha‐smooth muscle actin, and desmin. Benign fibrous histiocytoma of the prepuce in mule is rarely reported in veterinary literature.     

Haemoabdomen secondary to granulomatous periarteritis due to parasitism with Halicephalobus gingivalis in a mare

A 22‐year‐old Quarter Horse mare exhibited neurological signs consisting of head pressing, central blindness, minimal ataxia and dysphagia. Despite treatment, the mare collapsed and died shortly after onset of signs. On necropsy, there were approximately 15 l of free blood in the abdominal cavity. A 12 × 4 cm diameter, irregularly‐shaped, nodular, firm, tan/yellow mass was found adhered to the outer surface of the right lateral aspect of the caudal abdominal aorta. A similar mass also affected the caudal aspect of the right kidney. Histopathology of the aortic and renal masses revealed multiple coalescing granulomas containing intralesional nematodes compatible with Halicephalobus gingivalis. Inflammatory cells disrupted the aortic tunica adventitia as well as the outer tunica media. Similar exudate also affected the cerebrum, cerebellum and brainstem. Polymerase chain reaction amplification and sequencing of a portion of the large subunit ribosomal ribonucleic acid gene were performed using previously published primers for H. gingivalis to confirm the identity of the nematode. Although rupture of a blood vessel could not be demonstrated grossly, the histological findings suggest that inflammation may have breached a small calibre artery and caused the haemoabdomen.     

Ethmoid adenocarcinoma: Severe neurological complications after combined laser ablation and intralesional formalin injection

An 11‐year‐old Warmblood gelding with chronic bilateral epistaxis was diagnosed with an adenocarcinoma of the right ethmoid, based on transendoscopic biopsy. On computed tomography images, the cribriform plate was considered intact and the tumour was minimally invasive in surrounding tissue. The palliative treatment included a combination of surgical exploration and laser ablation. Following recurrence of the clinical signs one month later, intralesional formalin injection was performed. In the immediate post injection period, the horse developed severe neurological signs. Because of the overall poor prognosis, the horse was subjected to euthanasia. On post mortem examination, changes were seen in the frontal lobe consistent with diffusion of formalin through the cribriform plate. Care is needed when treating horses with intralesional formalin because macroscopic appearance of the cribriform plate may not relate to its functionality.     

Sand colic in a mule: A case report

A 25-year-old mule was showing signs of colic. Clinical examination revealed acute pain, bilateral abdominal distention, stretching out and standing in this position. Rectal palpation revealed a hardened mass in the ventral region of the pelvic inlet. Surgical intervention was accomplished and faecaliths removed by colotomy. The mule died unexpectedly and postmortem examination revealed sand masses within the right ventral and right dorsal colon which caused obstruction of the intestinal tract in sternal and diaphragmatic flexures, respectively. This appears to be the first report of sand colic in a mule in Iran.     

Large pituitary adenoma in an 8‐year‐old Arabian stallion

An 8‐year‐old Arabian stallion weighing 361 kg presented to Louisiana State University Veterinary Teaching Hospital with a 3‐month history of weight loss, exercise intolerance, long hair coat and recent history of seizures and aimless wandering in the pasture. An initial presumptive diagnosis of pituitary pars intermedia dysfunction (PPID) was made based on clinical signs. The initial examination revealed weight loss and loss of body condition (BCS 3/9), hypertrichosis, muscle wasting and reluctance to move when prompted. A neurological examination revealed dull mentation with no evidence of proprioceptive deficits in the limbs. Mild hyperglycaemia and a stress leucogram were noted on initial biochemical panel and haematology, respectively. Plasma adrenocorticotrophic hormone (ACTH) concentrations before and after thyrotropin releasing hormone (TRH) stimulation were markedly increased. Rapid slice computed tomography (CT) scan of the head before and after contrast revealed a large mass in the region of the pituitary gland suggestive of macroadenoma causing PPID. Prior to imaging, treatment consisted of supportive nursing care. Due to size of the pituitary gland (measuring 4.6 × 4.6 × 3.8 cm) and the presence of seizure‐like activity and dull mentation, the stallion was subjected to euthanasia. A necropsy was not performed. Pituitary macroadenomas in horses affected with PPID, who show neurological signs such as seizure‐like activity, dull mentation and aimless wandering, might have a poor prognosis and treatment with pergolide mesylate might not reduce pituitary gland size or relieve clinical signs. A CT scan is indicated in horses with neurological signs suspected of PPID to further evaluate pituitary gland size and surrounding structures and rule out other causes to better assess prognosis.     

Malignant Sertoli Cell Tumour in a Young Simmenthal Bull – Clinical and Pathological Observations

Tumours are rare in the bovine testicle. A case of malignant Sertoli cell tumour in a 29‐month‐old Simmenthal bull that was hospitalized with a history of severe unilateral scrotal swelling is reported. On inspection and palpation, the scrotal sac was found enlarged with fluctuant content in the right side. The right testicle was enlarged, hard and indolent. Also the right plexus pampiniformis and funiculus spermaticus were enlarged. Sonograms revealed severe changes in the right testicle with a loss of homogeneity and multiple hyperechogenic areas. After slaughter, the scrotum with testicles were removed and evaluated pathologically. On section, the right testicle contained areas of necrosis, haemorrhage, and mineralization. Histology showed Sertoli cells in tubular structures surrounded by dense fibrous stroma replacing normal testicular tissue. Both lymphatic and blood vessels were infiltrated by neoplastic cells. Immunohistochemically, the neoplastic cells stained positive for vimentin and negative for cytokeratin and S‐100. Based on the pathological observations a diagnosis of right‐sided malignant Sertoli cell tumour with vascular invasion and hydrocele was established.     

Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy

Objectives : To investigate the prognostic significance of the magnetic resonance (MR) findings of meningeal hyperintensity of the olfactory bulbs and tumour extension into the caudal nasal recess (CNR) in dogs with nasal tumours treated by radiotherapy. Methods : MR images of 41 dogs with nasal tumours treated with radiotherapy were reviewed. The occurrence of neurological signs and survival of patients with and without meningeal hyperintensity of the olfactory bulbs and tumour extension into the CNR were analysed together with possible confounding factors including intracranial extension and patient age. Results : There was no significant association between the presence of meningeal hyperintensity or CNR involvement and the occurrence of neurological signs. Although there was a tendency towards shorter survival in dogs with tumour extension into the CNR, multivariable analysis showed no significant difference in survival between dogs with/without CNR involvement, meningeal hyperintensity or intracranial tumour extension (P=0·12, 0·50 and 0·57, respectively). Clinical Significance : In dogs with nasal tumours treated with radiotherapy, tumour extension into the cranium is not necessarily associated with shorter survival in patients without neurological signs at time of diagnosis. Although a definite influence of CNR involvement on case outcome could not be demonstrated, studies with a larger population are warranted.     

Differentiating among horse (Equus caballus), donkey (Equus asinus) and their hybrids with combined analysis of nuclear and mitochondrial gene polymorphism

A novel and brief method of differentiating among horse (Equus caballus) and donkey (Equus asinus) and their hybrids (mule, E. asinus × E. caballus and hinny, E. caballus × E. asinus) with combined analysis of nuclear and mitochondrial gene polymorphism (CANMGP) was reported in the present report. A nuclear gene, protamine P1 gene of donkey was sequenced and compared with the known horse sequence from GenBank while a published equid mitochondrial gene, cytochrome b gene of donkey was compared with that of horse. In each of the two genes, a fixed nucleotide substitution within an exon that could be recognized by Dpn II restriction enzyme was found between the two species. Two pairs of primers were designed for amplifying the fragments within the two genes containing the informative nucleotide positions in 65 horses and 41 donkeys and 38 hybrids and conditions of polymerase chain reaction and restriction fragment length polymorphism (PCR‐RFLP) analysis were optimized. Horse, donkey and mule and hinny had their own specific cleavage patterns after the PCR‐RFLP analysis was performed, which made it very easy to identify them from each other. As multiplex PCR can be conducted with the two pairs of primers and only one restriction enzyme is involved in PCR‐RFLP analysis, the method described in the present study is a convenient way to identify horse and donkey and their hybrids. The idea involved in the method of CANMGP can be also used to differentiate other animal species or breeds and their hybrids.     

Primary Unilateral Fibroleiomyoma of the Ovary in a Pregnant Mare: A Case Report

Fibroleiomyomas of the ovary are rare. This smooth muscle tumour may develop and increase in size during pregnancy. Diagnosis is based on histological and immunohistochemical analyses. Histologically, the ovarian fibroleiomyoma consists of non‐invasive bundles of smooth muscle cells that synthesize collagen‐like extracellular matrix. This case report describes an ovarian fibroleiomyoma in a pregnant multiparous broodmare with a history of intermittent signs of colic.     

B‐cell lymphoma with Mott cell differentiation in a cat

A 12‐year‐old, male castrated Domestic Shorthair cat was presented to Animal Medical Center of Gifu Univeristy with anorexia and vomiting. Physical examination revealed an enlarged left tonsil and right mandibular lymph node (approximately 2–3× the normal size), and a submucosal mass on the right side of the epiglottis (1.5 × 2.0 cm). On computed tomography images, an enlarged left tonsil, and enlarged right mandibular, right pharyngeal, and left and right cervical lymph nodes were observed. Cytologic examination of smears of tonsil and lymph nodes revealed numerous medium‐ to large‐sized neoplastic lymphoid cells, approximately half of which contained one or several light‐blue homogenous globoid cytoplasmic inclusions (5–10 μm), which stained magenta with periodic acid–Schiff (PAS) stain. Histopathologic examination of the left tonsil revealed diffuse proliferation of medium‐ to large‐sized neoplastic lymphoid cells effacing the original lymphoid architecture. Half of the cells contained one or several eosinophilic globoid cytoplasmic inclusions, which stained magenta with PAS and showed positive immunohistochemical reactions for immunoglobulin M (IgM) and λ light chain. Neoplastic lymphoid cells were also CD20⁺, Pax5⁺, and MUM1⁺, and CD3^?. Thus, the neoplastic lymphoid cells expressed a B‐cell immunophenotype, and the globoid cytoplasmic inclusions represented an aberrant IgM λ light chain accumulation, similar to Russell bodies. B‐cell lymphoma with Mott cell differentiation was diagnosed based on cytologic, histopathologic, and immunohistochemical features. This is the first report of B‐cell lymphoma with Mott cell differentiation in a cat.     

B cell lymphoma and secondary leukaemia in a mule

A 20‐year‐old mule was evaluated for anorexia and fever. Haematological evaluation revealed a population of large, immature lymphoid cells and significant anaemia. Bone marrow aspiration was unsuccessful, and abdominal ultrasonographic evaluation was unremarkable. The mule was subjected to euthanasia due to poor prognosis, and necropsy and histological evaluation revealed multicentric B cell lymphoma. The leukaemic phase of lymphoma is rarely documented in equids, and is regarded as an indication of advanced or aggressive disease. To the authors' knowledge, lymphoma in a mule has been reported only once previously.     

Multiple endocrine neoplasias in a dog: Corticotrophic tumour,bilateral adrenocortical tumours,and pheochromocytoma

Summary

In a 10‐year‐old ovariohysterectomized standard Schnauzer, the finding of dexamethasone‐resistant hypersecretion of cortisol, the results of computed tomography, and elevated plasma concentrations of ACTH suggested the presence of both adrenocortical tumour and pituitary‐dependent hyperadrenocorticism. The dog made an uneventful recovery after bilateral adrenalectomy and remained in good health for 31/2 years with substitution for the induced hypoadrenocorticism. Then the enlarged pituitary caused neurological signs and eventually euthanasia was performed. The surgically excised right adrenal contained a well‐circumscribed tumour of differentiated adrenocortical tissue and in the left adrenal there were two adrenocortical tumours and a pheochromocytoma. The unaffected parts of the adrenal cortices were well developed and without regressive transformation. At necropsy there were no metastatic lesions. The cells of the pituitary tumour were immunopositive for ACTH and had characteristics of malignancy.

The present combination of corticotrophic tumour, adrenocortical tumours, and pheochromocytoma may be called ‘multiple endocrine neoplasia’ (MEN), but does not correspond to the inherited combinations of diseases known in humans as the MEN‐1 and the MEN‐2 syndromes. It is suggested that the co‐existence of hyperadrenocorticism and pheochromocytoma may be related to the vascular supply of the adrenals. Some chromaffin cells of the adrenal medulla are directly exposed to cortical venous blood, and intra‐adrenal cortisol is known to stimulate catecholamine synthesis and may promote adrenal medullary hyperplasia or neoplasia.     

Metastatic pancreatic polypeptide‐secreting islet cell tumor in a dog

Abstract: A 14‐year‐old female spayed Golden Retriever was presented to the University of Florida's Veterinary Medical Center with history of lymphoplasmacytic gastroenteritis, intermittent vomiting, watery diarrhea, and weight loss for over a year. CBC, biochemical profile, and urinalysis were within reference intervals. Abdominal ultrasonographic examination revealed mesenteric and jejunal lymphadenopathy and hyperechoic hepatic nodules. Cytologic examination of the enlarged lymph nodes revealed loosely cohesive cells with moderate nuclear pleomorphism and rare punctate eosinophilic cytoplasmic granules. The cytologic interpretation was metastatic neuroendocrine neoplasia. On surgical exploration, a mass was detected in the right lobe of the pancreas. Histologic evaluation determined the mass to be an islet cell tumor. Approximately 98% of cells were positive by immunolabeling for pancreatic polypeptide (PP), and only rare cells were positive for insulin or somatostatin. All cells were negative for glucagon, gastrin, vasoactive intestinal polypeptide, protein gene product 9.5, synaptophysin, and chromogranins A and B. Pancreatic tumors that primarily produce PP are rare in dogs, and this is the first report of both the cytologic and histologic features of an islet cell tumor predominantly secreting PP. Clinical signs for these tumors are typically absent or nonspecific; signs may include watery diarrhea, as noted in this dog, although the diarrhea may have resulted from lymphoplasmacytic gastroenteritis. Additional case studies are needed to further characterize the cytomorphologic features and clinical presentation of PP‐secreting islet cell tumor, or polypeptidoma, in dogs.     

Case-report. Malignant nerve sheath tumor in a cow with symptoms of suspected BSE

We report here on a 3 1/2-year-old mother cow with a malignant perineural tumour near the pontine angle of the cerebellum, but which first drew attention because of clinical signs of BSE. Neurological symptoms that manifested during the course of the disease included disturbances in behaviour, movement and aesthesia, as described by BRAUN et al. (2001) in cases of BSE. Inconsistent with a diagnosis of BSE were focal neurological disturbances (head held aslant to the right, tendency to fall to the right, right-sided facial weakness, left-sided nystagmus and ventral strabismus). Following euthanasia, magnetic resonance imaging (MRI) revealed a tumour in the cerebellopontine angle. Histological findings describe a malignant peripheral nerve tumour of the vagal nerve with rhabdoid differentiation (a so-called Triton tumour) with an intracranial and an extracranial part.     

Cytologic identification of fungal arthritis in a Labrador Retriever with disseminated Talaromyces helicus infection

An 8‐year‐old, neutered male Labrador Retriever presented with acute forelimb lameness. Clinical signs progressed over one week. On physical examination, right cubital joint effusion and bilateral axillary lymphadenomegaly were noted, and severe internal lymphadenomegaly was observed ultrasonographically. Granulomatous lymphadenitis with intralesional fungi was noted cytologically, and the dog was ultimately diagnosed with disseminated Talaromyces helicus infection via PCR of a pure isolate. Extensive medical therapy was pursued, and months later, an arthrocentesis was performed due to continued lameness and severe cubital joint effusion. The synovial fluid contained increased numbers of neutrophils, macrophages, and multinucleated giant cells. Frequent fungal hyphae were found both intracellularly and extracellularly. These basophilic organisms were 2‐4 µm in width with internal eosinophilic granules, roughly parallel walls, and occasional to frequent septa. Round to oval yeast‐like forms with thin, clear halos were also occasionally identified. Due to the severity of clinical signs, the right thoracic limb was amputated. Histologic examination of the cubital joint revealed marked granulomatous synovitis, fasciitis, panniculitis, and osteomyelitis, all with intralesional fungi. Talaromyces helicus is a very rare cause of disease, reported only in one other dog. Granulomatous lymphadenitis appears to be a feature of this disease, but this report is the first to describe a significant synovial component.     

Extreme neutrophilic leucocytosis and intrathoracic mass in a Fox Terrier

Extract

An 8-year-old female Fox Terrier was presented for acute anorexia and depression. A haemogram revealed extreme neutrophilic leucocytosis (136×10⁹/L neutrophils). By Day 4, the neutrophilia was more marked (214×10⁹/L segmented; 23×10⁹/L band). Imaging revealed a cranial mediastinal mass, pleural effusion and small pneumothorax. Needle aspiration of the mass showed cells resembling malignant histiocytes against a background of mature neutrophils. On Day 7, the mass was surgically removed. Histologically, it revealed a malignancy suggestive of histiocytic sarcoma intensely infiltrated with neutrophils. Immunocyto-chemical investigations are pending. Post-operatively, the dog's appetite and demeanour improved but breathing was laboured, and neutrophilia persisted (300×10⁹/L on Day 14). The dog was humanely killed on Day 14; post mortem examination revealed no distant metastases. This dog's illness is strongly reminiscent of a rare human condition, inflammatory malignant fibrous his-tiocytoma with leukaemoid reaction (IMFH-LR). In IMFH-LR, neoplastic cells produce cytokines that attract neutrophils to the tumour. Other cytokines stimulate the bone marrow to produce extreme neutrophilia. Although paraneoplastic neutrophilia has previously been described in dogs, this is an extreme example and the condition has not previously been associated with histiocytic or intrathoracic malignancies.