Aspergillosis

This is a gross photo of invasive aspergillosis. Note the irregular area of necrotizing pneumonia (abscess) surrounded by hemorrhage. Sometimes the central lesion is more rounded and is referred to as a target lesion.

The lung of this immunocompromised teenager with neutropenia displayed brown nodules. This photo on the left reveals an area of necrosis with very scanty surrounding inflammation. On the right is a silver stain of the necrotic area which shows branching hyphae consistent with Aspergillus species. The patient had acute myelogenous leukemia superimposed on aplastic anemia and had received chemotherapy and radiation therapy.

Aspergillosis is an opportunistic infection likely to infect the immunocompromised patient, especially the patient who is neutropenic or on steroids. The site of infection is often in pre-existing tuberculous cavities, dilated bronchi in bronchiectasis, or infectious abscesses. The accumulation of vast numbers of organisms can result in a fungus ball.

From the slide collection of the late Dr. Charles Kuhn

This is a specimen from a right upper lobectomy. The patient was a 75 year old man with a chronic cough. Routine chest x-ray showed a 3 cm right upper lobe mass. Bronchoscopy x 2 and CT directed fine needle aspiration were negative for tumor. The mass with approximately 2 cm greatest diameter represents a fungus  ball due to the growth of aspergillus colonies. The cavity may be lined by epithelium which often shows squamous metaplasia. The contents of the aspergilloma include colonies, blood clot, and cellular debris.

Aspergillus grows in scarred lung with pre-existing cavities secondary to tuberculosis, bronchiectasis, abscesses, sarcoidosis, neoplasia, or infarcts. Recurrent hemoptysis is a likely symptom.

Contributed by Dr. Michael Klein

From another case of pulmonary involvement this periodic-acid-Schiff (PAS) stain illustrates typical branching hyphae characteristic of Aspergillus. Immunocompromised patients, especially when neutropenic and/or on steroids are especially susceptible. Dissemination to other organs is not uncommon.

Among fungi aspergillus species form a genus within the family Trichocomaceae. These organisms are present in plant debris, soil and indoor air. Species are numerous and several of them have been documented as pathogens in humans. These organisms pose little if any danger to healthy persons but can cause serious infection in the immunosuppressed as noted in prior and subsequent photos in this pulmonary section. After Candida, aspergillus is the most common pathogen isolated in fungal opportunistic infections. In addition to lung infection, aspergillus can cause infections in the brain, meninges, ear, skin, nails, bone, eye, liver, and spleen among other organs

Contributed by Dr. Murray Resnick

This pulmonary artery section is from a 51 year old man with a history of asthma and a 15 year history of known sarcoidosis. He had been on steroids for a long time and was recently receiving antibiotics. He died suddenly during an episode of severe hemoptysis. This microphoto shows necrosis of the pulmonary artery wall with rupture. The inset shows the presence of invasive aspergillosis.

This inserted gross photo, from the same patient as the previous slide, is of the right lung near the hilum. It shows a large cavitary lesion. Microscopically, numerous aspergillus hyphae were noted in necrotic material lining the wall of the cavity.

Aspergillosis can be separated into colonizing and invasive forms. The colonizing form is represented by the formation of aspergillomas in which the fungus grows in pre-existing cavitary lesions. Invasive aspergillosis represents an opportunistic infection which occurs in immunocompromised patients. It causes necrosis of tissue and tends to invade blood vessels. In this case it resulted in fatal hemoptysis.

Contributed by Ronald DeLellis, MD and Wei Tian, MD