Respiratory · Year 1 · from Respiratory
Case 2: Sarcoidosis with Bilateral Hilar Lymphadenopathy
Case Presentation
A 32-year-old African American woman presents after an abnormal chest X-ray was found on routine pre-employment screening. She is asymptomatic except for mild fatigue. She has no respiratory complaints. On examination, she has erythema nodosum (tender red nodules on the anterior shins). Vital signs and oxygen saturation are normal.
Chest X-ray shows prominent bilateral hilar lymphadenopathy without parenchymal infiltrates (Stage I sarcoidosis). CT chest confirms bilateral hilar and mediastinal lymphadenopathy without lung parenchymal involvement. Pulmonary function tests are normal: FEV1 98% predicted, FVC 100% predicted, TLC 95% predicted, DLCO 90% predicted.
Laboratory evaluation shows elevated serum ACE level at 95 U/L (normal 8-52). Serum calcium is 10.8 mg/dL (high normal). 24-hour urine calcium is elevated at 380 mg. Ophthalmologic examination reveals asymptomatic anterior uveitis.
Bronchoscopy with endobronchial ultrasound-guided biopsy of a hilar lymph node is performed, revealing well-formed, non-caseating granulomas without evidence of infection or malignancy. Special stains and cultures for mycobacteria and fungi are negative. The diagnosis of sarcoidosis is confirmed.
Sarcoidosis is a multisystem granulomatous disease of unknown etiology. The non-caseating granulomas are composed of epithelioid histiocytes and multinucleated giant cells surrounded by lymphocytes. The disease can affect virtually any organ, but pulmonary involvement occurs in over 90% of cases.
Given her Stage I disease, lack of respiratory symptoms, and normal pulmonary function, the patient is managed with observation rather than treatment. Stage I sarcoidosis has a high rate of spontaneous remission (60-80%). Her ocular involvement requires topical corticosteroid drops. She is counseled to avoid excessive sun exposure and calcium/vitamin D supplements due to risk of hypercalcemia (granulomas produce 1,25-dihydroxyvitamin D). At 1-year follow-up, her hilar adenopathy has resolved spontaneously.
Key Learning Points
- Sarcoidosis is characterized by non-caseating granulomas; infection must be excluded
- Pulmonary staging: Stage I (hilar nodes only), Stage II (nodes + parenchymal), Stage III (parenchymal only), Stage IV (fibrosis)
- Stage I has high spontaneous remission rate; treatment reserved for symptomatic or progressive disease
- Extrapulmonary manifestations include ocular (uveitis), skin (erythema nodosum, lupus pernio), cardiac, and neurologic
- Hypercalcemia results from granuloma production of 1,25-dihydroxyvitamin D