Cryptococcal granuloma associated with jejunal intussusception in a horse

Abdominal cryptococcosis in dogs and cats: 38 cases (2000-2018)

INTRODUCTION

To report the clinical presentation, laboratory and imaging findings, treatment and outcome of abdominal cryptococcosis in dogs and cats in Australia.

MATERIALS AND METHODS

Canine and feline cases from Australia were retrospectively identified (2000 to 2018) via laboratory and referral centre searches for abdominal cryptococcosis diagnosed by cytology (needle aspirates) or histopathology (biopsy or necropsy) of abdominal organs/tissues. Signalment, presenting complaints, clinical signs, laboratory findings, medical imaging, latex cryptococcal antigen agglutination test (LCAT) titres, treatment and outcome data was collected.

RESULTS

Thirty-eight cases were included (35 dogs, three cats) in the study. Median age of presentation was 2 years for dogs and 6 years for cats. Common presenting complaints included vomiting (23/38), lethargy (19/38) and inappetence/anorexia (15/38). Abdominal ultrasound (25/38 cases) revealed mesenteric and intestinal lesions in most of the cases. On surgical exploration, seven cases had an intestinal lesion associated with an intussusception. Nineteen cases had a pre-treatment LCAT performed, with a median initial titre of 1:2048 (range 1:2 to 65,536). Twenty-four cases (23 dogs, one cat) received treatment, either medical, surgical or both. Median survival time for cases with combined medical and surgical treatment, surgical treatment alone or medical treatment alone was 730, 140 and 561 days, respectively. Eleven remain alive at the time of follow up.

CLINICAL SIGNIFICANCE

Abdominal cryptococcosis although rare should be a considered as a diagnostic possibility in an especially young dog presenting with gastro-intestinal signs. Older dogs can also present with this condition and should not be euthanised based on imaging alone due to the likenesses with neoplasia. With appropriate treatment and monitoring many dogs may have a prolonged survival period and some may be cured.

Equine Pulmonary Cryptococcosis: A Comparative Literature Review and Evaluation of Fluconazole Monotherapy

Cryptococcus is the most common fungal respiratory pathogen in Australian horses, manifesting primarily as pulmonary granulomas. Disease severity at presentation is dependent on the athletic use of the horse. The diagnosis and estimation of disease severity are centred around clinical findings, cytological evaluation of respiratory tract secretions, diagnostic imaging, and antigen titre testing. Both the lateral flow assay and the latex cryptococcal antigen titre are used, and important similarities and differences between species are discussed. Cryptococcus gattii occurs with greater frequency than Cryptococcus neoformans in equine pulmonic cryptococcosis and can be successfully treated with enteral fluconazole monotherapy, with disease severity determining treatment length.

Jejunal intussusception associated with lymphoma in a horse

A 2-year-old Thoroughbred horse presented with acute onset of colitis, and the intussuscepted jejunum was surgically resected. A transmural mass protruding into the lumen was found at the leading edge of the intussusceptum. Based on histological and immunohistochemical examinations, the mass was diagnosed as diffuse large B-cell lymphoma with metastasis to the mesenteric lymph nodes. Anatomical localization of the mass in the intussusception and absence of other obvious underlying diseases indicated that the intussusception had occurred in association with the mass. To our knowledge, this case is the first report of equine intussusception associated with focal intestinal lymphoma.

Multimodal treatment of recurrent sinonasal cryptococcal granulomas in a horse

CASE DESCRIPTION

A 7-year-old 509-kg (1,120-lb) Tennessee Walking Horse mare was evaluated because of bilateral mucosanguinous nasal discharge, intermittent right-sided epistaxis, and worsening dyspnea of 9 months' duration.

CLINICAL FINDINGS

Multiple masses in the nasopharynx were detected via endoscopic and radiographic examinations. Cytologic and histologic examinations of biopsy specimens of 1 mass revealed round yeasts with thick nonstaining capsules and occasional narrow-based budding that resembled cryptococcal organisms.

TREATMENT AND OUTCOME

Oral administration of fluconazole and organic ethylenediamine dihydriodide and intermittent intralesional injections with fluconazole, amphotericin B, and formalin resulted in resolution of lesions for a period of 2.5 years. The horse then developed exophthalmos, recurring clinical signs, and extensive nasopharyngeal masses. The masses were surgically debulked via a large frontonasal bone flap, and the horse was treated with IV injections of amphotericin B and long-term oral administration of fluconazole. Clinical signs did not recur in the following 2-year period. A presumptive diagnosis of cryptococcosis was made following cytologic and histologic evaluations of the masses; results of serologic analysis and fungal culture confirmed infection with Cryptococcus neoformans.

CLINICAL RELEVANCE

Cryptococcal infection of the upper respiratory tract in horses has previously been described as a uniformly fatal disease. As this case report illustrates, medical and surgical treatment of sinonasal cryptococcal granulomas in horses may be successful, but the importance of long-term follow-up and the potential for disease recrudescence should be considered. As efficacious antifungal agents become less expensive, their increased use will likely decrease mortality rates in horses with fungal infections.

Successful treatment of cryptococcal pneumonia in a pony mare

A 20-year-old Welsh Mountain Pony (212 kg) mare was initially presented for a chronic cough, fever, weight loss and low grade abdominal pain. She later developed dyspnoea, tachypnoea and exercise intolerance. The presence of multiple masses (up to 17 cm diameter) in the pulmonary parenchyma was established using lateral thoracic radiography and transthoracic ultrasonography. Encapsulated, budding yeasts were observed in smears made from transtracheal washings and needle aspirates of the pulmonary lesions. Cryptococcus gattii (synonym: Cryptococcus neoformans variety gattii; Cryptococcus bacillisporus) was cultured from the transtracheal washings and aspirates of the lung masses. The pony was successfully treated using daily intravenous infusions of amphotericin B (typically 0.5 mg/kg in 1 L 5% dextrose in water over 1 h, following premedication with 50 mg flunixin intravenously) over a 1 month period, until a cumulative dose of 3 g had been administered. Treatment was considered to be successful on the basis of progressive improvement in clinical signs, reduction in the size of pulmonary cryptococcomas, 48 kg weight gain and a reduction in the cryptococcal antigen titre from 4096 to 256, 1 year after cessation of treatment.

Disseminated cryptococcosis including osteomyelitis in a horse

A 4-year-old Arab mare was diagnosed with disseminated cryptococcosis, including osteomyelitis of the proximal phalanx of the left hind limb, osteomyelitis with associated soft tissue granuloma of a rib and disseminated, large cryptococcal nodules in the lungs. The lesion in the dorsoproximal aspect of the proximal phalanx had a large area of cortical lysis with spiculated periosteal new bone and extensive soft tissue swelling. The affected rib had a pathological fracture. Cryptococcal osteomyelitis has not been previously reported in horses but should be considered as a differential diagnosis, particularly in endemic regions.

Obstruction of the cecocolic orifice by ileocecocolic intussusception following jejunocecostomy in a horse

A 4-year-old Thoroughbred stallion was referred for signs of mild to moderate colic, anorexia, and decreased water intake of 3 weeks' duration. Ultrasonographic examination revealed an intussusception, the most common of which would be a cecal inversion or ileocecal intussusception. Surgical exploration identified an ileocecocolic intussusception with extension of the intussusceptum into the right ventral colon; however, the cause of the intussusception could not be identified. The intussusception could not be surgically corrected, and the horse was euthanatized. A side-to-side jejunocecostomy that had been performed previously was identified at necropsy. The ileal stump had intussuscepted into the right ventral colon and become hypertrophied, causing partial obstruction of the cecocolic orifice and clinical signs of colic. In horses requiring an ileocecal or jejunocecal anastomosis, the ileal stump may be left to slough within the cecum as part of the treatment for an irreducible ileocecal intussusception or intentionally inverted into the cecum when the ileal stump is necrotic and cannot be exteriorized and resected. Efforts should be made to minimize the size of the ileal stump to reduce the liklihood of intussusception.

Jejunal intussusception: a complication of functional end-to-end stapled anastomoses in two ponies

Jejunojejunal intussusception occurred after jejunal resection and stapled functional end-to-end anastomosis in two pony mares. In both mares, the lead point of the intussusception was the stapled functional end-to-end (FEE) anastomosis. The stapled free ends of jejunum were oversewn with an inverting suture pattern. A possible explanation for development of the intussusception was the acute angle created in the intestine by the FEE anastomosis. This angulation may have impaired flow of ingesta causing motility changes that predisposed the site to intussusception. Because the oversewn blind intestinal ends acted as the lead point for formation of the intussusception, it may be inadvisable to oversew the stapled anastomotic ends.

Cryptococcosis in seven horses

The clinical, radiographic and post-mortem findings in 6 horses with cryptococcal pneumonia and one horse with an abdominal cryptococcal granuloma are described. In pulmonary cryptococcosis, the lesions were either diffuse and multiple, with bilateral lung involvement, or localised mainly to the dorsocaudal region of one lung. The cases of diffuse multiple cryptococcosis were thought to be associated with haematogenous spread of the fungus after gastrointestinal infection and dissemination from regional lymph nodes. The localised form of the disease was thought to have been associated with inhalation of cryptococci. In all cases of pulmonary cryptococcosis, encapsulated yeast-like organisms were demonstrated in Wright's-stained sediment of tracheal washes. In the horse with the abdominal granuloma, cryptococci were present in a fine needle aspirate sample. Isolates of Cryptococcus neoformans var gattii were recovered from 2 of the 5 horses in which cultures were attempted. In addition to a history of previous illness that may have predisposed to infection, most horses in this report had been in areas in which Eucalyptus camaldulensis, or the closely related E rudis, were growing. In humans, an epidemiological relationship between E camaldulensis and infection with C neoformans var gattii has been suggested. Cases of equine cryptococcosis carry a poor prognosis and treatment was not attempted in any of these cases.