A retrospective study of the prevalence of calcium oxalate crystals in veterinary Aspergillus cases

Fungi in the genus Aspergillus are some of the most common fungal pathogens in veterinary species, primarily affecting the respiratory tract. In both human and veterinary cases, calcium oxalate crystals have been documented in sites of Aspergillus infection. Cases in multiple species (16 birds, 15 horses, 5 dogs, 1 ox, and 1 dolphin) were identified that had either positive cultures for Aspergillus sp., or had conidiophores present that could be identified as belonging to the genus Aspergillus. Histologic slides were examined to confirm the presence of oxalate crystals and how often they were identified on the original report. Calcium oxalate deposition was detected in 14 of 38 cases examined, including A. fumigatus, A. versicolor, A. niger, and unspecified Aspergillus sp. infections. Calcium oxalate crystals were identified in 11 of 16 avian cases, as well as in 1 of 1 bovine, 1 of 15 equine, and 1 of 5 canine cases. Crystals were described in only 3 of the 14 original pathology reports of these cases, indicating that identification and reporting of crystals in histologic specimens could be improved. All the tissues with crystals were respiratory tissues with air interfaces, including nasal sinus, trachea, syrinx, lung, and air sac. In cases with crystals identified on H&E-stained sections, crystals were frequently not present or were fewer in number in tissue sections stained with Gomori methenamine silver and periodic acid-Schiff. Routine polarization of slides of fungal infections, especially in the respiratory tract, should be considered to check for calcium oxalate crystals.

Pulmonary dystrophic oxalosis and its possible relation to fibrosis in an aged Gentoo penguin (Pygoscelis papua)

A 20-year-old Gentoo penguin was found dead with a clinical history of inappetence and dyspnoea. At necropsy, the lungs showed severe congestion/hemorrhage and atelectasis. Histopathologically, fibrosis was observed exclusively around parabronchi with severe collagen deposition. In fibrotic lesions, there were numerous depositions of crystalline structures accompanied by epithelioid cells and multinucleated giant cells (foreign body type). In addition to irregularly lamellar structures as the morphology, the crystals were demonstrated calcium oxalate (CaOx) by the Alizarin red S staining with and without polarized light and von Kossa's staining. Myocobacteria and fungi were not found by special and immuohistochemical stainings. Pulmonary dystrophic oxalosis is a very rare lesion in Gentoo penguin.

Choanal fungus ball mimicking a tumour

We report the first case of an isolated choanal fungus ball in a 28-year-old man with a previous history of nasopharyngeal carcinoma, who was treated with radiotherapy 14 years ago. The initial diagnosis was a recurrent tumour or a secondary neoplasm. Histopathological examination confirmed a fungal infection. There are no previous reports of a fungus ball located at the posterior choanal region. Although it has been reported that bacteriology of sinonasal region would be different in irradiated patients, there is no study reporting fungal infections in irradiated patients in English literature. In this report, the clinical presentation, relevant radiologic findings and management of sinonasal fungus ball and its relationship with previous radiotherapy were discussed with the literature knowledge.

Invasive aspergillosis in developing countries

To review invasive aspergillosis (IA) in developing countries, we included those countries, which are mentioned in the document of the International Monetary Fund (IMF), called the Emerging and Developing Economies List, 2009. A PubMed/Medline literature search was performed for studies concerning IA reported during 1970 through March 2010 from these countries. IA is an important cause of morbidity and mortality of hospitalized patients of developing countries, though the exact frequency of the disease is not known due to inadequate reporting and facilities to diagnose. Only a handful of centers from India, China, Thailand, Pakistan, Bangladesh, Sri Lanka, Malaysia, Iran, Iraq, Saudi Arabia, Egypt, Sudan, South Africa, Turkey, Hungary, Brazil, Chile, Colombia, and Argentina had reported case series of IA. As sub-optimum hospital care practice, hospital renovation work in the vicinity of immunocompromised patients, overuse or misuse of steroids and broad-spectrum antibiotics, use of contaminated infusion sets/fluid, and increase in intravenous drug abusers have been reported from those countries, it is expected to find a high rate of IA among patients with high risk, though hard data is missing in most situations. Besides classical risk factors for IA, liver failure, chronic obstructive pulmonary disease, diabetes, and tuberculosis are the newly recognized underlying diseases associated with IA. In Asia, Africa and Middle East sino-orbital or cerebral aspergillosis, and Aspergillus endophthalmitis are emerging diseases and Aspergillus flavus is the predominant species isolated from these infections. The high frequency of A. flavus isolation from these patients may be due to higher prevalence of the fungus in the environment. Cerebral aspergillosis cases are largely due to an extension of the lesion from invasive Aspergillus sinusitis. The majority of the centers rely on conventional techniques including direct microscopy, histopathology, and culture to diagnose IA. Galactomannan, β-D glucan test, and DNA detection in IA are available only in a few centers. Mortality of the patients with IA is very high due to delays in diagnosis and therapy. Antifungal use is largely restricted to amphotericin B deoxycholate and itraconazole, though other anti-Aspergillus antifungal agents are available in those countries. Clinicians are aware of good outcome after use of voriconazole/liposomal amphotericin B/caspofungin, but they are forced to use amphotericin B deoxycholate or itraconazole in public-sector hospitals due to economic reasons.

An aspergilloma caused by Aspergillus flavus

Chronic pulmonary aspergillosis is broad term encompassing chronic cavitary, chronic fibrosing pulmonary aspergillosis and aspergilloma. All affect patients with structural lung diseases and many have subtle genetic immune defects. Almost all cases are caused by Aspergillus fumigatus. Here we report a patient with an aspergilloma which had Aspergillus flavus recovered from a surgical specimen and serum containing detectable precipitating antibody.

Aspects of oxalosis associated with aspergillosis in pathology specimens

Oxalosis (calcium oxalate deposition) is associated with various conditions, including aspergillosis. Some Aspergillus species produce oxalic acid, which reacts with blood or tissue calcium to precipitate calcium oxalate. Calcium oxalate crystals exhibit various shapes and are strongly birefringent. These occur in cytological specimens, as well as in tissues of patients with Aspergillus infection. Aspergillus species are hyaline septate moulds, and they can be accurately recognized in pathology specimens only if conidial heads (fruiting heads) are present. When these structures are not observed, detection of associated oxalosis in a mould infection supports the pathological diagnosis of aspergillosis. The presence of oxalosis is helpful when microbiological identification or immunohistological techniques for fungi are not available. Calcium oxalate crystals can induce cellular injury by several mechanisms, and there is increasing evidence that oxalosis-induced tissue damage may occasionally lead to a poor clinical outcome. This review discusses the diagnostic value and the potential clinical significance of oxalosis associated with aspergillosis.