Histopathological Spectrum of Granulomatous Skin Lesions: A Review

Abstract

Background and objectives: Granulomatous dermatoses are the most frequently encountered dermatological disorders in tropical countries with leprosy and tuberculosis as the leading causes. Although granulomatous skin lesions are very prevalent in society today, dermatopathologists often face diagnostic challenges while reporting these lesions due to the similar histopathological features or tissue reaction patterns seen in these lesions with diverse etiologies. The purpose of this study is to review the various causes and patterns of granulomatous skin lesions and a sequential approach to diagnosis of individual lesions accurately. Materials and methods: A comprehensive search of all literature available on granulomatous skin diseases between 2000 and 2018 was conducted, using keywords such as "granulomatous dermatosis, " "cutaneous tuberculosis, " "leprosy, " and "histopathological study" in the databases such as PubMed, ProQuest, and Google Scholar. The articles that satisfied the criteria were included in the final review. Results: The available evidence from the existing systematic literature reviews and articles suggested that the various tissue reaction patterns observed in granulomatous skin lesions are classified as epithelioid, palisaded, suppurative, xanthogranulomatous, foreign body, and other granulomatous patterns. These tissue reaction patterns are caused by infections, foreign bodies, metabolites, chemicals, and malignancies. Conclusion: Granulomatous dermatoses are a heterogeneous group of skin disorders that are frequently encountered in diagnostic dermatopathology. The histomorphology of a granuloma has to be correlated with the clinical history and ancillary techniques including special stains, culture, and molecular methods are necessary to arrive at a definitive diagnosis.

Histopathological Features of Cutaneous Tuberculoid Granuloma Disorders

“…Secondary syphilis usually presents as papulosquamous eruptions and can also affect mucous membranes. 22,23 The secondary stage is caused by hematogenous and lymphogenous spread of treponemes over several weeks or months. 9 Rash is a clinical manifestation in almost all cases of secondary syphilis.…”

“…16 Syphilitic granulomas are generally found in the tertiary stage of the disease, although they are uncommon in the secondary phase. 22 This infection involves the cardiovascular system, central nervous system, and skeletal system. However, lesions can also occur in the testes, lymph nodes, and skin.…”

Histopathological Features of Cutaneous Tuberculoid Granuloma Disorders

“…1,3 Secondary syphilis Secondary syphilis usually presents as papulosquamous eruptions and can also affect mucous membranes. 22,23 The secondary stage is caused by hematogenous and lymphogenous spread of treponemes over several weeks or months. 9 Rash is a clinical manifestation in almost all cases of secondary syphilis.…”