Histologic, Cytologic Diagnosis of Fungal Infections

Editor’s note: The May issue of ADVANCE for Administrators of the Laboratory included an article of the same title that examined H&E and special stains, histologic and cytologic preparations, molecular studies and more. Here the author explores applications in forensic and dermatology cases.

The need to prepare, stain and study the morphology of mycotic organisms can be a challenge. Proper techniques are a must; known positive controls, technical expertise, automation, symptoms and history are all necessary tools to help in the identification of fungal and microorganism diseases.

Histological and cytological preparations are the pathological laboratory tests of choice. Molecular assays are continuing to enter the diagnostic arena to further probe the depth of study for fungal origin, and the need for technical expertise to study and become proficient in identification of fungal and microorganisms is required.

Forensic, Autopsy Cases

The H and E stain (and many special stains) can offer a great deal of assistance to the forensic pathologist or medical examiner. Many times it is a fungal infection or some other microorganism that may have caused death to a person and is just not found until the autopsy. The length of time a body has been deceased, exposed to sunlight, heat and/or cold temperatures all play a role in the cause of death. Even though the tissues may be decayed and necrotic a fungal or other microorganism can still be identified and hopefully lead to a diagnosis.

Dermatology Cases

As well, numerous dermatological cases are stained for and treated for fungal infections. Rashes, scaling and reddish areas are signs and symptoms of some type of infectious disease or illness, many of which develop into deep, invasive areas of necrosis and infection and can lead to death. The GMS and PAS stain are often the special stains of choice to help in making a diagnosis for treatment. Fluorescent stains offer a great deal of flexibility for fresh dermatology specimens in the diagnosis of many fungi. The usefulness of fluorescent antibodies in dermatological studies has been well established. The detection and identification of Cryptococcus neoformans, Blastomyces dermatitidis, Coccodioides immitis and Sporothrix schenchii can be achieved by immunofluorescence. The utilization of fluorescence requires good antibodies, reagents and skilled technologists to perform properly.

M. Lamar Jones is anatomic pathology manager, Wake Forest University Baptist Medical Center, Winston-Salem, NC, and program director, School of Histotechnology, Davidson County Community College, Lexington, NC.

Continue to page 2 for a list of suggested readings…

Suggested Readings

1. Color Alas and Text of the Histopathology of Mycotic Diseases, Chandler, FW, Kaplan, W., Ajello, L., Year Book Publishers, Chicago, 1980.

2. Histotechnology A Self Instructional Text, Carson, FL; Hladik, C, 3rd edition, ASCP Press, Chicago, 2009.

3. Theory and Practice of Histopathologcal Techniques, Bancroft, J: Gamble, M.,6th edition, Churchill Livingstone, Baltimore, 2008.

4. Theory and Practice of Histotechnology, Sheehan, D, Hrapchak, BB, 2nd edition, Mosby, St. Louis, 1982.

About The Author