Introduction: Although sarcoidosis has well-described clinical and imaging features, its diagnosis remains challenging, requiring integrated clinical, radiological, and histopathological assessment, along with the exclusion of other granulomatous diseases. Differential diagnoses include infections such as tuberculosis, autoimmune conditions, and environmental or occupational exposures. Silicosis is particularly relevant due to its clinical and radiological overlap with sarcoidosis and its potential coexistence with other conditions, including autoimmune diseases.

Clinical Case Description: A 54-year-old male, former blacksmith and construction worker (35-year silica exposure), presented with fever, dyspnea, fatigue, anorexia, and a 10kg weight loss over 6 months.

Workup revealed anemia, elevated ACE (79 U/L), hypergammaglobulinemia and a monoclonal IgG-kappa band. Chest CT showed bilateral "eggshell" calcified lymphadenopathy and centrilobular micronodules. BAL identified lymphocytic alveolitis (40,8%, CD4/CD8 ratio of 1.95). Sarcoidosis was suspected, and corticosteroid therapy (60mg/day) initiated, leading to clinical and analytical improvement.

During follow-up, he reported persistent dyspnea and new-onset dysphagia. A meticulous physical examination identified SSc hallmarks: Raynaud’s phenomenon, sclerodactyly, and microstomia. Repeat chest CT confirmed persistent mediastinal lymphadenopathy and identified esophageal parietal thickening. Laboratory reassessment revealed a positive Rheumatoid Factor (25.4 UI/mL) and elevated anti-Scl-70 antibodies (22 U/mL).

After integrating all findings— occupational exposure, clinical stigmata, laboratorial markers, and imaging—Erasmus Syndrome (association between silica exposure and systemic sclerosis) was suspected and the case was reviewed in a multidisciplinary meeting. Treatment with mycophenolate mofetil was started, resulting in significant clinical improvement.

Conclusions: This case highlights the diagnostic challenge of differentiating sarcoidosis from silica-related granulomatous lung diseases. Importantly, the differential diagnosis was further complicated by the presence of constitutional symptoms (fever, fatigue, weight loss) which were ultimately attributable to systemic sclerosis rather than sarcoidosis. Additionally, it underscores that even in the era of advanced technology, the clinician's eye remains a very powerful tool.