Middle lobe syndrome: a nationwide study on clinicopathological features and surgical treatment.

INTRODUCTION: Middle lobe syndrome (MLS) is a relatively uncommon lung disease that is characterized by damage to the middle lobe and often needs surgical intervention.
OBJECTIVE: To study clinical, radiological and histological features of all patients who underwent surgical resection for MLS in Iceland over a 13-year period, including evaluation of surgical outcome.
METHODS: Information on patients who underwent surgery of the right middle lobe in Iceland from 1984 to 2006 was obtained from a centralized diagnosis and pathology registry. Clinical data were collected retrospectively from clinical records from hospitals and from private offices. All pathology specimens were reviewed.
RESULTS: We studied 18 patients, 3 males and 15 females between the ages 2 and 86 years (mean 55). The most common clinical features were recurrent infection (n = 15), chronic cough with productive sputum (n = 9), chest pain (n = 8) or dyspnea (n = 7). The most common findings on chest radiographs and on computerized tomography of the chest were atelectasis, consolidation and bronchiectasis. One patient had a foreign body. The most common major histological finding was bronchiectasis in nine patients, and two had foreign body reaction. Minor findings included bronchiolitis, organizing pneumonia and peribronchial inflammation. All patients survived surgery with minor peri- and postoperative complications.
CONCLUSION: MLS is more common in females, and recurrent infections, chronic productive cough and dyspnea were the most common symptoms. Bronchiectasis is the most common histological finding. MLS can be treated effectively with lobectomy with low mortality and rate of complications.