A 38-year-old woman from rural Maharashtra presents with a 3-month history of progressive dyspnea, dry cough, and constitutional symptoms. Chest X-ray shows bilateral hilar lymphadenopathy with upper lobe infiltrates. Serum ACE level is elevated at 85 U/L (normal <40). Transbronchial lung biopsy reveals non-caseating granulomas. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient presents with classic features of sarcoidosis: bilateral hilar lymphadenopathy, upper lobe infiltrates, elevated ACE, and non-caseating granulomas on biopsy. The diagnosis is highly likely. ## Why Serum and Urinary Calcium? **Key Point:** Hypercalcemia and hypercalciuria occur in 5–10% of sarcoidosis patients due to extrarenal 1α-hydroxylase activity in granulomas, leading to excessive calcitriol production. **High-Yield:** Assessment of calcium metabolism is essential BEFORE initiating corticosteroid therapy because: 1. Corticosteroids can worsen hypercalcemia paradoxically in the short term (by reducing urinary calcium excretion) 2. Hypercalciuria predisposes to nephrolithiasis and chronic kidney disease 3. Baseline calcium status guides dose and duration of steroid therapy ## Management Algorithm for Newly Diagnosed Sarcoidosis ```mermaid flowchart TD A[Non-caseating granulomas + clinical features]:::outcome --> B{Assess organ involvement}:::decision B --> C[Serum calcium, 24h urine calcium]:::action B --> D[Pulmonary function tests]:::action B --> E[Ophthalmology exam]:::action C --> F{Hypercalcemia or hypercalciuria?}:::decision F -->|Yes| G[Restrict calcium/vitamin D, monitor renal function]:::action F -->|No| H[Observe if asymptomatic]:::action D --> I{FEV1 <80% or symptoms?}:::decision I -->|Yes| J[Start corticosteroids]:::action I -->|No| K[Watchful waiting]:::action ``` ## Why NOT the Other Options? | Option | Why Incorrect | |--------|---------------| | Anti-TB therapy | Tuberculosis is ruled out by non-caseating granulomas; TB granulomas are caseating. Starting ATT without excluding TB mimics is inappropriate. | | IV methylprednisolone | Corticosteroids are indicated only if there is symptomatic pulmonary disease (FEV₁ <80%) or extrapulmonary involvement (hypercalcemia, uveitis, cardiac). This patient has mild symptoms; observation + baseline investigations first. | | EBUS-TBNA | Already has tissue diagnosis (biopsy-proven non-caseating granulomas). Further sampling adds no diagnostic value and delays necessary baseline investigations. | **Clinical Pearl:** Sarcoidosis is a diagnosis of exclusion; TB and fungal infections must be ruled out first. The Scadding staging system (0–IV) guides prognosis but does not determine immediate management — organ-specific assessment does. [cite:Robbins 10e Ch 15]