Candida

J Cutan Pathol. 2008 Jan;35(1):27-30. Abstract quote

The Congo red staining properties of Candida organisms in clinical tissue specimens have not, to the best of our knowledge, previously been reported.

The objective of this study was to determine if the Congo red staining characteristics of Candida vs. Histoplasma, Pityrosporum and Blastomyces could provide useful diagnostic information. Archival tissue specimens that contained Histoplasma, Pityrosporum, Candida and Blastomyces were stained with Congo red. The results of the Congo red staining were compared with the diagnoses which were originally rendered on the tissue.

Nine out of nine cases (100%) of Blastomyces were Gomori methenamine silver (GMS) positive and Congo red positive, seven out of seven cases (100%) of Histoplasma were GMS positive and Congo red negative, and eight out of eight cases (100%) that had Pityrosporum were GMS positive and Congo red positive; these results corroborate with previously described staining patterns for each respective organism. Nine out of nine cases (100%) that had Candida were GMS positive and Congo red negative.

Differential Congo red staining of Candida organisms can provide a rapid and accurate method of diagnosis in tissue specimens vs. Blastomyces and Pityrosporum, but not vs. Histoplasma.

Disease Associations
Pathogenesis
Laboratory/Radiologic/Other Diagnostic Testing
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Special Stains/ Immunohistochemistry/ Electron Microscopy
Differential Diagnosis
Prognosis
Treatment
Commonly Used Terms
Internet Links

PATHOGENESIS	CHARACTERIZATION
Habitat	Can be recovered from nearly every setting including soil, food, and hospitals Normal commensal organism on mand
Transmission	Majority of infections are endogenous but human-human transmission is possible
Immune response	Intact integument is most important defense against invasion Neutrophils and monocytes attack the invading organism-if these cells lack myeloperoxidase or the capacity to generate hydrogen peroxide and superoxide anion, Candida will not be destroyed Lymphocytes play role in cell mediated immunity IgG and humoral response play role in opsonizing organism

LABORATORY/ RADIOLOGIC/ OTHER TESTS	CHARACTERIZATION
Laboratory Markers
Culture media	Grows well on routine blood agar and fungal media Biphasic blood cultures and lysis centrifugation may facilitate recovery

GROSS APPEARANCE/ CLINICAL VARIANTS	CHARACTERIZATION
General	Species of primary human importance include: C. albicans C. guilliermondii C. krusei C. parapsilosis C. stellatoidea (now C. albicans) C. tropicalis C. pseudotropicalis C. lusitaniae C. rugosa C. glabrata (formerly Torulopsis glabrata)
VARIANTS
Thrush
Esophagitis
Nonesophageal, mucous membrane gastrointestinal candidiasis
Vaginitis
Cutaneous Candidiasis syndromes
Generalized cutaneous candidiasis
Erosio interdigitalis blastomycetica
Candida folliculitis
Candida balanitis
Cutaneous lesions of disseminated candidiasis
Intertrigo
Paronychia and onychomycosis
Diaper rash
Perianal candidiasis
Chronic mucocutaneous candidiasis
Deep Organ Involvement
CNS
Respiratory tract
Cardiac
Candida endocarditis
Urinary tract endocarditis
Arthritis, osteomyelitis, costochondritis, myositis
Peritonitis
Hepatitis, gallbladder, and spleen
Vasculitis
Ocular
Disseminated candidiasis

HISTOLOGICAL TYPES	CHARACTERIZATION
General	Small thin walled ovoid cells (4-6 um) that reproduce by budding
VARIANTS
GIANT BLASTOCONIDIA
Giant blastoconidia of Candida albicans. A case report and review of the literature. Alasio TM, Lento PA, Bottone EJ. Department of Pathology, The Mount Sinai Hospital, New York, NY 10029, USA.	Arch Pathol Lab Med. 2003 Jul;127(7):868-71 Abstract quote We describe a patient with extranodal non-Hodgkin lymphoma who developed systemic candidiasis after treatment with a cyclophosphamide-based chemotherapy regimen. Histologically, the fungal organisms demonstrated markedly enlarged blastoconidia with a variety of morphologic forms, mimicking other mycotic organisms, such as Cryptococcus neoformans, Blastomyces dermatitidis, and Paracoccidioides brasiliensis. The in vivo occurrence of such giant forms is rare, and when observed histologically may result in an erroneous diagnosis or a diagnosis of multiple mycotic organisms.

DISEASE ASSOCIATIONS	CHARACTERIZATION
Immunosuppression

SPECIAL STAINS/ IMMUNOPEROXIDASE/ OTHER	CHARACTERIZATION
Special stains	In tissue sections, standard PAS and GMS stains for fungus are adequate
Evaluation of the use of Congo red staining in the differential diagnosis of Candida vs. various other yeast-form fungal organisms. Axelson GK, Giorgadze T, Youngberg GA. Department of Pathology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.	J Cutan Pathol. 2008 Jan;35(1):27-30. Abstract quote The Congo red staining properties of Candida organisms in clinical tissue specimens have not, to the best of our knowledge, previously been reported. The objective of this study was to determine if the Congo red staining characteristics of Candida vs. Histoplasma, Pityrosporum and Blastomyces could provide useful diagnostic information. Archival tissue specimens that contained Histoplasma, Pityrosporum, Candida and Blastomyces were stained with Congo red. The results of the Congo red staining were compared with the diagnoses which were originally rendered on the tissue. Nine out of nine cases (100%) of Blastomyces were Gomori methenamine silver (GMS) positive and Congo red positive, seven out of seven cases (100%) of Histoplasma were GMS positive and Congo red negative, and eight out of eight cases (100%) that had Pityrosporum were GMS positive and Congo red positive; these results corroborate with previously described staining patterns for each respective organism. Nine out of nine cases (100%) that had Candida were GMS positive and Congo red negative. Differential Congo red staining of Candida organisms can provide a rapid and accurate method of diagnosis in tissue specimens vs. Blastomyces and Pityrosporum, but not vs. Histoplasma.