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Palisading granulomas caused by infectious diseases
W P Su1, M K Kuechle, M S Peters
1Department of Dermatology, Mayo Clinic, Rochester, MN 55905.
Abstract:
We recently encountered a palisading granuloma in which an infectious cause was not considered until special stains revealed hyphae and tissue culture revealed organisms of phaeohyphomycosis. A review of more than 2,500 cases of various granulomas revealed 11 cases of palisading-type granuloma caused by infection, including phaeohyphomycosis, nontuberculous mycobacteriosis, papulonecrotic tuberculid, tuberculoid syphiloderm, cat-scratch disease, sporotrichosis, cryptococcosis, and coccidioidomycosis. Infectious disease should be considered in the differential diagnosis of palisading granuloma. Special stains for bacteria, fungi, and acid-fast bacilli should be performed in biopsy specimens that have a palisading granuloma pattern with central necrosis, especially in immunosuppressed patients.
Insights
Infectious causes of palisading granulomas are often missed. Special stains on biopsy specimens are crucial for diagnosing infections like phaeohyphomycosis in immunosuppressed patients.
Area of Science:
- Pathology
- Infectious Diseases
- Dermatology
Background:
- Palisading granulomas are a histological pattern observed in various conditions.
- Infectious etiologies are not always considered in the initial differential diagnosis.
Observation:
- A case of palisading granuloma was initially diagnosed without an identified infectious cause.
- Special stains and tissue culture revealed phaeohyphomycosis.
Findings:
- A review of 2,500+ granuloma cases identified 11 instances of infectious palisading granulomas.
- Infections included phaeohyphomycosis, mycobacteriosis, syphilis, cat-scratch disease, sporotrichosis, cryptococcosis, and coccidioidomycosis.
Implications:
- Infectious diseases must be considered in the differential diagnosis of palisading granulomas.
- Biopsy specimens with palisading granuloma and central necrosis warrant special stains for pathogens, particularly in immunocompromised individuals.