This study retrospectively analyzed 84 patients with middle lobe syndrome (MLS) divided into a pediatric group (<15 years old) and adult group (>15 years old). The main causes of MLS in the pediatric group were non-specific infection and TB. In the adult group, the main causes were non-specific infection, TB, and malignancy. Surgical intervention including lobar resection had good outcomes for non-malignant causes, while malignant etiologies had less favorable prognoses.

1. Tarek Mohsen MD, FRCS
Cardiothoracic Surgeon
Cairo University Hospitals

2.  The term “middle lobe syndrome” was first
introduced by Graham and colleagues in
1948 for isolated middle lobe atelectasis
caused by lymph node compression.
 Othercauses of a shrunken middle lobe
without lymph node compression was
pointed out later by Rubin and Rubin in
1950 for other causes including benign and
malignant tumors or bronchiectasis.

5.  The clinical presentation of (MLS) differs among
age groups.
 In children it is a cause for persistent or
intermittent wheezing in atopic and non atopic
children making early recognition difficult and a
lag between diagnosis and treatment is the rule.
 In adults specific clinical presentations like fever,
cough, purulent sputum and hemoptysis usually
point to early recognition for the clinical
syndrome

6.  Inthis study we retrospectively analyzed
the etiology, indications and results of
surgical intervention in the past six years
for patients with MLS in different age
groups.

7.  A retrospective review of 84 consecutive patients
with different age groups presented with MLS
and, Cairo University Hospitals between Feb.
2004 and Dec. 2010 was undertaken.
 Our patients were divided according to their age
group into pediatric group < 15 years old (39
patients) and adult group > 15 years old (45
patients).
 Both groups followed the same protocol of
medical management prior to referral for
surgical management.

8.  At the chest department all patients underwent detailed history
taking, thorough medical examination and an initial chest
radiograph in both postero-anterior and lateral views showing
middle lobe collapse / consolidation and or bronchiectasis.
 The initial management was conservative in the form of broad
spectrum antibiotics, physiotherapy, mucolytics, inhaled
bronchodilators, and inhaled corticosteroids.
 Re-evaluation after 4 – 6 weeks was done and in the event of
persistent or recurrent of symptoms and lack of radiographic
amelioration, these patients were subjected (HRCT) and
bronchoscopic evaluation including bronchial lavage (BAL).
 Patients who were thought to be a high risk for malignancy e.g.
age, smoking were placed on a faster track with initial HRCT and
bronchoscopic biopsy.

9.  Referralfor surgical management was
based on failed conservative treatment,
chronicity of the disease, bronchiectasis,
hemoptysis, destroyed lobe, and
malignancy.

10.  Fibro-opticbronchoscopic evaluation
was done in all patients in the adult
group to explore the tracheobroncheal
tree. BAL was sent for quantitative
culture and sensitivity for aerobic,
anaerobic, and acid fast bacilli.
 Patients
below 10 years had rigid
bronchoscopy as a routine.

11.  Surgicalmanagement included resection
of the middle lobe and/or lingula,
mediastinoscopy, and VATS.
 Allpatients were followed up at 2 weeks,
3 months and every 6 months and then
yearly for 1-4 years at the outpatient
clinic.

12. Variables Group A (no. 39) Group B (no.45)
Age (Mean) 5 ± 2.7 39.7 ± 14.2
Sex (m:f) 18m:21f 24m:21f
Presentation
Cough 39 (100 %) 41 (91.1 %)
Wheeze 26 (66.6 %) 16 (35.5%)
Sputum 17 (43.5 %) 26 (57.7%)
Shortness of breath 10 (25.6 %) 22 (48.8 %)
Recurrent infection 23 (58.9%) 10 (22.2 %)
Hemoptysis 1 (2.5 %) 14(31.1 %)
Chest pain 3 (7.6%) 5 (11.1 %)
Weight loss 3 (7.6%) 16 (35.5 %)
Pleural effusion 0 2 (4.4 %)
Duration of symptoms before 3-48 mo 2-36mo
diagnosis 14.5 9.4
(Range and mean)

13.  Bothgroups show a long period between
symptoms and intervention ranging from
2 months – 4 years. However, in patients
presenting with hemoptysis or malignant
etiology this period was short 1-3 months

14. Radiological findings Group A (no.39) Group B (no.45)
Collapse 25 (64.1 %) 28 (62.2 %)
Bronchiectasis 14 (35.8 %) 17 (37.7 %)
1) Middle lobe 11 (28.2 %) 12 (26.6 %)
2) Lingula 2 (5.1 %) 3 (6.6 %)
3) Bilateral 1 (2.5 %) 2 (4.4%)
Pleural effusion 2 (4.4%)
Mediastinal lymphadenopathy 2 (4.4%)

15. Variables Group A (no. 39) Group B (no.45)
Bronchial stenosis 1 (5.1 %) 0
Endobronchial obstruction
Mucosa edema. 22 (56.4 %) 13 (28.8 %)
Granulation tissue. 1 (5.1 %) 0
Mucus plug. 4 (10.2 %) 1 (2.2 %)
Blood clot. 1(5.1 %) 5 (11.1 %)
Mass /tumor. 1 (5.1 %) 5 (11.1 %)
Extra-luminal obstruction 1 (5.1 %) 0
Normal 7 (17.9 %) 20 (44.4 %)
Purulent discharge 19 (48.7 %) 15 (33.3 %)

16. Organisms Group A (19/39) Group B (18/45)
48.7 % 40 %
S. Aureus 8 (20.5 %) 4 (8.8 %)
H. Infleunzea 4 (10.25 %) -
P. Aeruginosa 2 (5.1 %) 9 (20 %)
S. Pneumoniae 2 (5.1 %) -
K. Pneumoniae 2 (5.1 %) 4 (8.8 %)
TB 1 (2.5 %) 1 (2.2 %)

17.  Inthis report, the main etiological factor in
group A causing MLS pathology was non-
specific infection in 34 patients (87.1 %), 4
patients (10.2 %) were TB and one patient
(2.5 %) had endobronchial hamartoma
causing MLS.
 Ingroup B, 13 patients (28.8 %) were due to
non-specific infection, 14 patients (31.1 %)
due to TB and 18 patients (40 %) were due
to malignant etiology.

18.  Surgical
intervention varies according to the
pathology,
 Ingroup A, 36 patients (92.3 %) underwent
middle lobectomy, 2 patients (5.1 %)
underwent lingulectomy and one patient
underwent staged left lower lobectomy
followed 4 weeks later by middle lobectomy.

19.  In group B, 33 patients (73.3 %) underwent middle
lobectomy, 3 patients (6.6 %) underwent lingulectomy.
Bilobectomy was done in 3 patients (6.6 %) when the tumor
mass from the middle lobe crossed the fissure. 2 patients
(4.4 %) underwent staged bilateral lobectomies bilateral
bronchiectasis.
 Mediastinoscopy was done for 2 patients (4.4 %) to evaluate
associated mediastinal lymph nodes that were positive for
adenocarcinoma.
 VATS was done for 2 patients who had associated moderate
pleural effusion to evaluate the pleura for possible malignant
spread. Both patients had positive pleural nodules
(adenocarcinoma).

20.  In this series there was no morbidity or mortality; outcome varies
according to the pathology.
 In group A, 25 patients (64.1 %) underwent middle lobectomy for
a collapsed lobe.
 14 patients (31.1 %) presented with bronchiectasis, 11patient
underwent middle lobectomy, 2 patients underwent lingulectomy
and 1 patient had bilateral staged lobectomy. Left lower
lobectomy was primary targeted due to extensive disease,
followed 4 weeks by middle lobectomy when patient symptoms
didn’t improve dramatically.
 This group of patients with bronchiectasis had excellent
improvement except for 1 patient who had mild recurrence of
symptoms 3 years after the operation, and whose CT scan showed
bronchiectatic changes at the apical segment of the right lower
lobe, she was controlled by medical treatment.

21.  In group B, 28 patients (62.2 %) had middle lobectomy due
to collapse,
 and 17 patients (26.6 %) had resection for bronchiectasis. All
had excellent outcome with control of symptoms at follow up
that extended for 3 years.
 18 patient in this group had malignant etiology, 14/18
patients underwent resection of the middle lobe and
additional 3/14 had lower lobectomy.
 4 patients were inoperable due to metastasis (2 patients with
mediastinal lymph nodes and another 2 patients with
malignant effusion). 10 patients (22.2 %) in this group
survived 7-36 months with a mean of 17.7 ± 10.6, while 8
patients (17.7 %) exceeded 4 year follow up.

22.  Middlelobe syndrome (MLS) is
characterized by a spectrum of diseases
from recurrent atelectasis and
pneumonitis to bronchiectasis of the
middle lobe. It has been described
among all age groups

23.  Inthis study 2/3 in both groups
presented with atelectasis and 1/3 with
bronchiectasis.
 Non- specific infection was present in
87.1 % of patients and 10.2 % had TB in
group A.
 Malignancy was the main etiology in
group B accounting for 40 % of patients
and almost 30 % had TB.

24.  Thepathological changes that led to MLS are
either obstructive or non-obstructive.
 In
this series 31 patients (36.9 %) had no
obstruction on bronchoscopy (10 patients in
group A and 21 patients in group B), and a
deep fissures were noted at operation
separating the middle lobe from both the
upper and lower lobe and thus interrupting any
collateral ventilation and explaining the
collapse.

25.  53patients (63 %) had obstruction on
bronchoscopy ranging from partial (27 patients
(32.1 %) in group A and 18 patients (21.4% in
group B) to complete (2 patients in group A and
6 patients in group B) obstruction.
 Inthese 53 patients deep oblique fissure was
complete in all cases; however in few patients
7/53 (13.2 %) the transverse fissure was
incomplete.

26.  The management of MLS is essentially
conservative in pediatric age group
particularly when early intervention is
followed. However in our series patients
were referred after failure of
conservative treatment in 2/3 of patients
and bronchiectasis in 1/3 of patients

27.  The management in adult group is conservative in
inflammatory category of this group of patients
representing 27 patients (60 %), however due to
chronicity and hemoptysis in 14 patients (31.1 %)
surgery was indicated.
 In the malignant subgroup of the adult group, 18
patients (40 %) presenting with malignancy were
managed surgically. In the malignant subgroup 14/18
patients (77.7 %) were operable and underwent lobar
resection, 4 patients (22.2 %) were inoperable due to
distant metastasis.

28.  Surgical management of MLS is safe.
 Theoutcome depends on the etiology and
age, in this series inflammatory causes
carries the best prognosis, whereas
malignant causes have unfavorable
prognosis.