Abstract Rationale Sarcoidosis is a multisystem granulomatous disease of unknown etiology. The relationship between cancer and sarcoidosis is complex and multifaceted. A granulomatous reaction to malignancy, also known as a sarcoid-like reaction (SLR), is the development of non-necrotizing epithelioid cell granulomas in patients with cancer who do not meet criteria for systemic sarcoidosis. The clinical features, anatomic distribution of granulomas, and underlying mechanisms of SLR remain poorly characterized. We aimed to review the literature to summarize the clinical features and better understand the association between SLR and cancer. Methods We conducted a systematic review with descriptive synthesis of published case reports and case series, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies included human cases with a diagnosis of sarcoidosis within one year of the malignancy diagnosis were included. A comprehensive PubMed search was performed for articles published between 1960 and 2024. Data were extracted into Microsoft Excel and summarized descriptively, including demographics, cancer type, organ involvement and timing of sarcoidosis relative to malignancy, and treatment. Results Of 303 articles identified through database searching, 105 were included. A total of 199 SLR cases associated with malignancy were identified. The mean age was 54 years; 51% were female. The most frequently reported malignancy was melanoma (20.1%), followed by genitourinary cancers (18.6%), lung cancers (11.1%), and lymphoma (11.1%). Nearly half of all reported SLR cases (46.7%) occurred in the setting of metastatic disease, while 20.6% were localized or non-metastatic. Granulomatous inflammation distant from the primary malignancy was present in 56.3% of cases, and approximately 50.4% of these occurred in patients with metastatic disease. The etiology of SLR was directly attributed to malignancy in 110 cases (55.3%), whereas 72 cases (36.2%) were secondary to therapy. Immune checkpoint inhibitors were implicated in 38 cases (19.1%), while cytotoxic chemotherapy accounted for 51 cases (25.6%). Targeted therapies (e.g., BRAF and MEK inhibitors) were reported in 8 cases (4.0%). Conclusion Sarcoid-like reaction is most frequently observed in patients with melanoma, genitourinary, lung, and hematologic malignancies, often in the context of metastatic disease. Importantly, over half of all cases demonstrated granulomatous inflammation at sites distant from the primary tumor, including extrathoracic organs and lymph nodes. This finding underscores a critical diagnostic challenge, as SLR may mimic systemic sarcoidosis. Clinicians should maintain a high index of suspicion and carefully exclude underlying malignancy before establishing a diagnosis of sarcoidosis. This abstract is funded by: None
Al-Juboori et al. (Fri,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: