Gazi Medical Journal
2000; 11: 39-42
BRONCHOGENIC CYST WITH
UNUSUAL LOCALIZATION
Velit HALİT, M.D., S.
Aykut ALTUNKAYA, M.D., Aynur OĞUZ*, M.D., Cumhur SİVRİKOZ, M.D. Yıldırım
İMREN, M.D., Mustafa BÜYÜKATEŞ,M.D., Tolga ENGEL, M.D.
Gazi University, Faculty
of Medicine, Department of Thoracic and Cardiovascular Surgery and
Pediatrics*, Ankara, Turkey
SUMMARY
Cystic lesions of the
mediastinum constitute rare but important dilemma. Bronchogenic cysts
represent a spectrum of bronchopulmonary malformations which result from
an abnormal budding of the tracheabronchial tree. The tracheal bud
develops from the primitive foregut as a ventral diverticulum during the
forth week of gestation and undergoes further branching and
differentiation. The bronchogenic cyst is a result of aberretional
development. They can settle in mediastinal or intraparanchymal regions.
These lesions represent 27,5 % of all mediastinal cysts. In this report,
we present a case of bronchogenic cyst with unusual localization.
INTRODUCTION
Bronchogenic cysts
constitute the majority of mediastinal cysts (53.3 %). The typical
localization of these lesions is the tracheobronchial tree located
posterior to the carina. Although there are different localizations like
paratracheal, carinal hilar, paraesophageal, or at the level of azygoz
vein (1-2), they are mainly attached to trachea or tracheal cartilages.
In case of free tracheal communication, an air-fluid level can be
detected.
The clinical
presentations are usually releated to tracheal and tracheobronchial
compressions. Typical localization of bronchial cysts have been reported
for esophageal, pericardial, dermal, cervical, diaphragmatic or
intradural spaces, but such localizations are very rare (3-4).The
histopathology of bronchial cyst consists of columnar acilier epithelium
and cartilage (5).
Complications releated to
bronchial cysts include tracheal and bronchial or esophageal
compression, and rarely, superior vena cavae obstruction, cardiac
symptoms like arrythmia, right ventricular obstruction, pneumothorax or
pleural effusion have been reported as well (6-8). Differential
diagnosis includes secondary metastatic tumor, lymphoma, teratoma,
neurogenic tumor, embryonic sarcoma and other benign and malign
mediastinal lesions.
CASE
REPORT
An 8-year-old girl with
fever and cough was admitted to our hospital with a story of a
neurogenic mass on the right lung detected by pediatrists while they
were searching for the etiology of fever.
Physical examination
showed normal findings. Routine laboratory examinations except chest
X-ray and CT were found to be in physiological limits.
Chest X-ray revealed a
3x2 cm homogenous mass with sharp edges located in middle zone of right
lung that refers to posterior paravertebral sulcus (Fig.1)
CT showed a 3 cm,
sharp-edged polypoid mass with low density, located in the posterior
paravertebral sulcus of right hemithorax.
The patient underwent
surgery. The right lung was approached through right posterolateral
thoracotomy. During exploration, a 3x2x1 cm mass, full of viscous liquid
was detected in the posterior paravertebral sulcus. That cystic mass was
pink, soft and polypoid. Further exploration showed no adherence with
neighboring organs. The cystic mass was removed. In pathologic
examination, the cystic structure was found to be covered by respiratory
tract epithelial internally, and the wall consisted of cartilage
islands, mucous gland and lymphoid aggregates (Fig. 2-3).This mass was
reported as "Bronchogenic cyst".
The postoperative course
was uneventful.
DISCUSSION
Bronchogenic cysts are
the most frequent mediastinal cystic lesions (53.3%) (7), which primary
lesions are reported to be 8% . Bronchogenic cysts are the result of
bronchopulmonary differentiation during formation of tracheabronchial
tree. A small number of bronchogenic cysts originate from respiratory
paranchymal tissues and they can be detected in very atypical tissues
like throat, skin, pericardium,diaphragarm and intradural space (3-4).
Although they are located
in posterior and anterior mediastinum, they are usually found in middle
mediastinum, frequently located on the tracheabronchial tree and
esophagus, paratracheal, carinal, hilar and paraesophageal structures
(1,2).
Typical histological
appearance consists of a cyst wall, which is covered by ciliated
columnar epithelium or cartillage bodies. If cysts are related with the
tracheal bronchial tree, the frequency of existence of cartillage body
reaches to 32.7%. If they are related with eosophagus, this rate
dimenshes to 25% (6).
A classification was
created upon the existence of symptoms (14). In a study, asymptomatic
patient rate was found to be 72 %, while the symptomatic group was
recorded as 80% (8).
Pain is the major
symptom. Chest pain, dyspne, cough and fatique are also seen. Infection
occurs if the cyst is opened to bronchial structures. Tracheo-bronchial
compression, enhanced intraluminal pressure due to esophageal stress,
extreme obstruction of SVC (Superior vena cava), arythmia, infundibular
obstruction of right ventricle, pulmonary obstruction, pleural effusion
and pneumothorax are major complications (6-8). Some reports pointed
that bronchogenic cysts are related with adeno-squamous carcinoma (6-9).
A sharp edged solitary
non-calcified oval and circular homogenous mass is detected in X-ray
evoluations. Sometimes lobulated cysts with air-liquid level can be
seen.
It is best evaluated by
CT, which reveals a cyst with a low density. If the cyst is infected,
the existence of calcification and protein increases density and the
wall width enlarges, whic is best evaluated by ultrasound and MRI
(6,9,10).
Metastatic tumors,
lymphoma, teratoma, neurogenic tumors, embryonal sarcoma, inflammatory
lymphadenopathy, pulmonary sequestration, hemangioma, lipomas,
nonenteric pericardial and esophageal duplication cysts are among
differential diagnosis.
Surgery is nessecary
either in symptomatic and non-symptomatic but complicated patients. On
the other hand medical follow-up is advisable for uncomplicated
symptomatic cases.
Total excision is the
best method of treatment. Percutaneous needle aspiration is
contraindicated either for diagnosis or treatment but if a high risk
exists, it can be evaluated as an alternative treatment.
Resection with V.A.T.S
(Video-assisted thoracic surgery) is a frequent and successful way of
treatment. But a strict evaluation should be done when choosing cases
for such an intervention. Especially, centrally located, metastatic
lesions, developed from tracheobronchial tree cause complications and
risks. It is also very difficult in children. Some authors reported the
complication rate of 30% in adults and 9 % in children.
In conclusion,
bronchogenic cysts that may cause symptoms and complications must be
diagnosed early and treated by surgical removal.
Correspondence
to:
Dr. Velit HALİT
Gazi Üniversitesi Tıp Fakültesi Göğüs Kalp Damar Cerrahisi
Anabilim Dalı;
Beşevler 06500 ANKARA-TÜRKİYE
Phone : 0 312 - 214 10 14 / 5619
Fax : 0 312 - 212 90 14
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