bud from the foregut that becomes isolated from the rest of the trache - PDF document

bud from the foregut that becomes isolated from the rest of the tracheobronchial tree produc-well circumscribed non-echogenic cystic mass was observed measuring 1.51.3 cm. Histo-logically, the cyst was lined by cilicated, pseudostratified, columnar epithelium with interspersed Bronchogenic cysts are generally detected shortly after birthor in early childhood. These lesions are benign congenital develop-anomalies of the tracheobronchial buds from the primi-and the most common extrapulmonary locationCutaneous bronchogenic cystsare rarely reported. The most common location is the supraster-nalnotch, followed by the presternal area, neck, and scapula.report here on a case of cutaneous bronchogenic cyst that occurredover the sternum in a 13-month-old boy.CASEREPORTA 13-month-old boy presented with a growing mass over thephysical examination, a non-movable, soft mass with inflamma-torysigns was detected on the overlying skin of the sternum.There was no sinus tract or discharge from the observed lesion.On ultrasonography, a well circumscribed non-echogenic cystic1.3 cm, was recognized in the subcuta-neous fat layer over the sternum (Fig. 1). The excised cyst wasunilocular and contained a yellowish seromucinous material. Therewas no connections between the cyst and the surrounding tissue.Histologically, the cyst was lined by ciliated, pseudostratified,columnar epithelium and goblet cells scattered among the cili-ated epithelial cells (Fig. 2). There were several bundles of smoothwall. There was histologic transition from columnar epitheliumplasma cells, infiltrating into the cystic wall to form lymphoidaggregates were present (Fig. 4B), and these cells were also infil-tratedinto the stratified squamous epithelium. Cartilage was notseen. Near the main cystic lesion, there was an incidental epider-malinclusion cyst having acute suppurative inflammation with aforeign body reaction. It had no connection with bronchogenicBronchogenic cysts are abnormalities of pulmona

ry differen-with these lesions present with symptoms of infection or com- pression on the vital structures.mediastinum, along the tracheobronchial tree, or peripherally inTo date, 60 cases of cutaneous bronchogenic cyst have been reported in the English literature.of cutaneous bronchogenic cyst have been reported in Koreanliterature, and all of them have occurred in males.Clinically, cutaneous bronchogenic cysts are cystic masses thatare found shortly after birth or in early childhood. They are asymp-tomatic, and some of them have a fistulous opening that drainsfour times. The most common location of cutaneous bronchogeniccyst is the suprasternal notch, followed by the presternal area, A well circumscribed non-echogenic cystic mass is recog-nizedin the subcutaneous tissue over the sternum on ultrasonog- Fig. 2.-thelium and goblet cells scattered among the ciliated epithelialcells. Fig. 3.There are several bundles of the smooth muscle fibers (A,arrows) and mucous glands (B) in the cystic wall. Numerous lymphocytes and plasma cells are infiltrated in the cys-ticwall to form lymphoid aggregates. The origin of bronchogenic cysts in the extrathoracic subcu-taneous tissues can be readily explained by their embryologicdevelopment. The laryngotracheal groove separates the primi-tive foregut into dorsal and ventral structures beginning in theseparation will be completed with a dorsal component formingthe lung buds and a ventral component forming the foregut.Most bronchogenic cysts arose from the developing lung budstructures are formed during this period. Bronchogenic cysts inby anterior migration of an intrathoracic bronchogenic cyst orby a pinching off of the fusing sternal bars on the developingthese sequestered structures in the developing embryo.Cutaneous bronchogenic cysts are characteristically lined bywith goblet cells, and these cysts also show other componentsincluding smooth muscle fibers, mucous glands and cartilagesthat are present in 80%, 53% and 7%

of the cysts, respectively.The following lesions should be considered in the differentialdiagnosis: cutaneous ciliated cyst, thyroglossal duct cyst, epider-mal inclusion cyst, branchial cyst, dermoid cyst, and trichilem-The definitive diagnosis of the excised lesion restson the histologic evaluation. Bronchogenic cysts are typicallylined by respiratory epithelium, and they often contain smoothor thyroglossal origin may contain respiratory epithelium, butsmooth muscle fibers, cartilages or mucous glands should not bepresent. Cutaneous ciliated cysts occur in the lower extremitieswith papillary projections that resemble fallopian tubes. Thyroglossal duct cysts always appear as midline cervical masses. Theirwall may be lined by respiratory and squamous epithelium, andthyroid follicles are frequently present. The lining of the epider-malinclusion cyst is stratified squamous epithelium. Branchialcysts are lined by stratified squamous epithelium and surroundedby lymphoid tissue. Dermoid cysts are lined by an epidermis thatpossesses various epidermal appendages. The lining of trichilem-malcyst is squamous epithelium without an intervening gran-ular cell layer.In our case, the diagnosis may have been thrown into confu-squamous epithelium, and the lymphoid aggregates may sug-gest branchial cysts rather than cutaneous bronchogenic cysts.However, we considered the squamous epithelium as a metaplasticchange due to the chronic inflammation. Lymphoid aggregatesmay be found in cutaneous bronchogenic cysts as was describedwho reported a case of a presternal bronchogenicanomaly with lymphoid aggregates. Unlike the cutaneous bron-chogeniccysts, branchial cysts do not show smooth muscle fibersor secretory cells. Because of these reasons, we diagnosed this caseTotal excision is advised for the treatment of cutaneous bron-chogenic cyst as mucoepidermoid carcinoma can arise from abronchogenic cyst, as was reported by Tanaka 


 






 
#
'

( )
*+
,
(
+



-
 1
34
5
 

6 
,


+


7 
.
./
+
8)
5(
.
9
( 

%
"
 
:

; 
4
 
 
93
(
*
3) )-
58
5 
3


"


 4

)
:


+
0

&#x;&#x=%5;&#x;&#x/
;&#x-94.;�/
?
9/- 

-
'
%$
?
(
)(5
-

()
 .
 -
?
.
:





:
; 

/
#&&!

5



5 
/ /

:/



:

; 
4%. 

' 4%' 4
9
'
 
;
 %
9 
+

.

:

#
5

@3

?
(/
(
.

:

%

)
/;
:  

/
!
1$"1
3
?
.
 ?
(
3
5
-
?
.
 
C;:





 
,
 
-
? (




(
?



:



) 



#&&!
0&"
0$2% 
3

3/
8

(
? 
8
.

:
0
5/



-/


$
8:
,
8 /
*9
, 
'
+

:

/ %
5 
,'
85
-
*
+
"
./  
:/
/  ;/
:

;/
:

/ '/
*,
( )
*+

 

.
/
$2!#

@

+
+




:
-"


;

)
:


 
 ##
+
38
* 

( 



)
;  
/;

./

/
#&&&!
##"#1
-
5
/-)
,
5



5; /
%/:

/

.

;
2#!
1#"
$&1%