Carr et al used noninvasive tests to evaluate an asymptomatic patient with bilateral hilar lymphadenopathy. These can help identify patients who may not need an invasive procedure for diagnosis. The authors are from Massachusetts General Hospital, Boston City Hospital and the Purdue Frederick Company.


Patient selection:

(1) bilateral hilar lymphadenopathy

(2) duration >= 6 weeks

(3) one of the following:

(3a) asymptomatic

(3b) mild symptoms such as cough



(1) severe symptoms (with marked weight loss, fever, dyspnea)


The differential diagnosis consisted primarily of:

(1) sarcoidosis

(2) tuberculosis

(3) deep fungal infection (if the person has been to a region where endemic)

(4) malignant lymphoma


The noninvasive panel consists of:

(1) serum angiotensin-converting enzyme (ACE)

(2) PPD

(3) fungal serology tests for a deep fungus with history of being in an endemic region



• An elevated ACE with negative PPD and fungal serology suggests sarcoidosis but other conditions can cause this pattern.

• Pulmonary tuberculosis or deep fungal infection can cause an elevation in serum ACE.

• Deep fungal infections mentioned were histoplasmosis and coccidioidomycosis. Blastomycosis might also be a consideration,


Factors that may affect the panel's effectiveness:

(1) Taking an ACE inhibitor

(2) Having risk factors for malignant lymphoma, peripheral lymphocytosis or significant lymphadenopathy Immunophenotyping of peripheral blood or peripheral lymph node biopsy may obviate the need for bronchoscopy,

(3) The presence of significant risk factors for lung cancer (normally would be associated with unilateral lymphadenopathy and/or significant symptoms)

(4) The presence of uveitis or erythema nodosa suggests sarcoidosis.

(5) The presence of significant immunosuppression.


Key points:

(1) Carefully selected patients can often be managed effectively without invasive procedures.

(2) Knowing the prevalence of different diseases in a patient population can help guide the diagnostic process.

(3) A complete history and physical examination may disclose findings that may support a conservative approach.


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