Mediastinal lymphadenopathy in patients with or without previous malignancy: EUS-FNA-based differential cytodiagnosis...

Mediastinal lymphadenopathy (ML) is a cause for concern, especially in patients with previous malignancy. The investigation of choice is thoracic CT with a variable sensitivity and specificity requiring tissue diagnosis. We used endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for cytodiagnosis of ML in patients with and without previous malignancy. The cause, distribution of lesions, and incidence of second cancers were investigated.

Linear echoendoscopes and 22-gauge needles for cytology were used for EUS-FNA. A cytological diagnosis of malignancy was accepted, and histology or consistent follow-up of at least 9 months confirmed benign results.

One hundred fifty-three patients underwent EUS-FNA between November 1997 and November 1999 (mean age, 60 yr; range, 13-82 yr; 105 men). Cytology was adequate in 150 patients. Final diagnosis was malignancy in 84 and benign in 66 patients (sensitivity, specificity, and diagnostic accuracy: 92%, 100%, 95%, respectively). In 101 patients without previous cancer cytology identified 48 malignant (lung, 41; extrathoracic, 7) and 51 benign lesions (inflammation, 35; various, 9; sarcoidosis, 7) (sensitivity, specificity, accuracy: 88%, 100%, 94%). Fifty-two patients had prior malignancy, mostly in extrathoracic sites. Cytology revealed recurrences in 21 patients, second cancer in 9 and benign lesions in 21 patients (inflammatory, 11; sarcoidosis, 8; tuberculosis, 1; abscess, 1) (sensitivity, specificity, accuracy: 97%, 100%, 98%).

In patients without previous cancer malignant ML originates from the lung >80%. In those with previous malignancy recurrence of extrathoracic sites is the major cause. Benign lesions and treatable second cancers occur in a significant frequency, emphasizing the need for tissue diagnosis. EUS-FNA is a safe and minimally invasive alternative for cytodiagnosis in the mediastinum.