Case Presentation: A 33 year-old woman presented with a one day history of fever and sharp pleuritic chest pain. She had a one month history of progressive fatigue, dyspnea with exertion, bilateral ankle swelling and painful bilateral nodules on her anterior shins. She has no recent travel history, TB exposures, weight loss or personal or family history of any rheumatological disease. On exam, ankles were tender with bilateral edema. Numerous tender, raised, 1cm erythematous papules were present on the anterior legs from knees to feet bilaterally. There were no wheezes, rhonchi or crackles, oral lesions, murmurs or a friction rub, or lymphadenopathy on exam.
CT chest revealed no pulmonary embolism but showed numerous bilateral pulmonary nodules suggestive of miliary disease with upper lobe predominance along with bulky hilar lymphadenopathy. Inflammatory markers, CRP and ESR, were mildly elevated and ANA was 1:160. The anti-dsDNA, ANCA, Histoplasma antigen, Legionella antigen, Coccidiodes antigen, and Quantiferon TB Gold tests were all negative. Vitamin D and Calcium levels were normal. Three induced sputum samples were negative for acid fast bacilli. Skin biopsy of the cutaneous lesions revealed granulomatous dermatitis consistent with sarcoidosis. She was prescribed prednisone 40 mg daily with close follow up with rheumatology was arranged.

Discussion: Miliary pattern of lung nodules are often found incidentally on chest imaging and necessitates further work up by internists. The differential diagnosis includes tuberculosis, pneumoconiosis, metastatic lesions, endemic fungal lung infections, Langerhans cell histiocytosis as well as sarcoidosis. In this case, the evidence of fever, erythema nodosum, and polyarthralgias were strongly suggestive of sarcoidosis and the skin biopsy confirmed the diagnosis. Other laboratory studies aided in ruling out infectious diagnoses on the differential.

Sarcoidosis is a disorder, typically of young adults, that is characterized by the presence of noncaseating granulomas in involved organs that could include the lung, skin, joint, or eye. Our patient had Lofgren’s syndrome, an acute presentation of sarcoidosis that is characterized by the combination of hilar adenopathy, erythema nodosum, polyarthralgia, and fever. It is seen in 9-34% of patients. Although most cases of sarcoidosis are discovered incidentally on chest imaging, up to 30% of patients can present with extrapulmonary manifestations. In the lung, the more common finding on imaging is distinctive bilateral hilar lymphadenopathy with or without right paratracheal adenopathy. This finding is present in about 40% of patients. Miliary opacities are rare and seen in less than 1% of cases of sarcoidosis.

Conclusions: In a patient with miliary opacities on imaging, considering a broad differential is necessary. When compatible clinical and histological evidence is available, miliary opacities can be seen in a patient with sarcoidosis in the setting of Lofgren’s syndrome.