Review
Abstract:Bronchogenic cysts are one of the subtypes of congenital
cysts, which are extremely rare in the spinal canal. We report a case of
a 19-year-old woman,with complaints of neck and shoulder pain with
numbness in her hands and weakness in her right extremity. The magnetic
resonance imaging of the cervical spinal revealed a cystic lesion from
C4 to C5 vertebral levels. Finally, after surgical resection, the case
was diagnosed as a bronchogenic cyst. By reviewing the literature, it is
found that only less than 30 cases have been reported so far.
Clinical message:A case of a 19-year-old woman,with complaints of neck
and shoulder pain with numbness in her hands and weakness in her right
extremity. The MRI of the cervical spinal revealed a cystic lesion from
C4 to C5 vertebral levels. Postoperative histopathologocal examination
suggested it is a bronchogenic cyst
Key words:spinal bronchogenic;Cervical;Extramedullary;Neurosurgery,
Spinal lesion
Bronchogenic cysts are congenital cystic lesions originating from
endoderm, dominated by pseudostratified ciliated columnar epithelium.It
often occurs in the mediastinum, but rarely occurs in the spinal
canal.[1] The symptoms of intraspinal bronchogenic
cysts are mainly compression symptoms, mainly pain, numbness, limb
weakness,and even hemiplegia.[2] Because it is a
benign lesion, surgical resection can have an ideal prognosis.
- History and Physical Examination: The patient was a 19-year-old female
who complained of neck and shoulder pain for 3 months, numbness in
both hands,and right limb weakness for 1.5 months. The patient’s neck
pain was needle-like pain, with numbness in both hands and a decrease
in pain and temperature sensation. The muscle strength of the right
upper limb was grade 4, the lower limb was grade 3(Code Muscle
Strength Grade), and the muscle strength of the left limb was normal.
- Radiological findings:Preoperative CT found a low-density foci in the
spinal canal at the C4-C5 level. The CT value was about 23HU, the
largest cross-sectional area was about 11mm*19mm, and the shape was
irregular. The lesion was hypointense on T1 and hyperintense on T2
images(Figure1-2).
- We performed a lesion resection under electrophysiological monitoring
on our patient. During the operation, the tumor was seen as a
gray-white cyst with a complete capsule and black dot-like substances
on the cyst wall. When we open the cyst wall, we can see the clear
fluid flowing out, We completely removed the cyst wall during the
operation. Electrophysiology monitoring suggests that the electrical
activity of the right limb is improved after the resection of the
lesion. Histopathologocal examination showed the cyst was lined by
ciliated columnar epithelium, suggestive of a bronchogenic
cyst(Figure4).
- After the operation, the patient’s muscle strength returned to normal,
the symptoms of neck and shoulder pain were significantly relieved,
and the numbness in the left hand improved after about 1 week.
Postoperative MR (Figure3)and CT showed no residual cyst. After the
patient was discharged from the hospital, we followed up with the
patient regularly, and the patient did not have similar symptoms
again.After 3 months we performed an MRI on the patient, the MRI shows
that there is no spinal cord edema, hemorrhage or recurrence of the
cyst after operation.
Discussion
According to WHO, a bronchogenic cyst is an endogenous cyst whose
contents are the epithelium of the respiratory
tract.[3] Bronchogenic cysts account for 0.5%
of cystic lesions in the spinal canal. The origin of a bronchogenic
cyst is not completely known, but this pathological entity has been
proposed to result from three hypotheses during embryogenesis.[4]At first, it is assumed that the endoderm and
ectoderm do not separate completely during differentiation of the
inner cell mass. Secondly, the cyst is considered to originate from
the ectoderm because of its potential to form the endoderm and
paraxial mesoderm. Lastly, it is attributed to the split notochord
syndrome which can explain the ectopic bronchogenic cyst. When the
duplication or separation of the notochord is incomplete, ectopic
cysts are generated.[5]As a benign lesion, the symptoms of intraspinal bronchogenic cysts are
mainly pain, limb weakness, paresthesia, abnormal urine and stool,and
other placeholder effects. Symptoms are exacerbated when the cyst
ruptures, becomes infected, increases in size, or is
traumatized.[6] The most commonly seen
characteristic on MRI is homogeneous isointense or hypointense lesions
on T1WI, hyperintense lesions on T2WI, and noncontrast-enhancing
lesions after intravenous contrast injection. Clinicians should
differentiate IEBCs from the following diseases: (1) Spinal arachnoid
cysts are more commonly found in the dorsal part of the thoracic
spinal canal. They show similar signals to cerebral spinal fluid on
all MRI sequences. (2) Spinal epidermoid cysts mostly occur in the
lumbosacral region. MRI can show various intensities due to different
proportions of liquid within the lesion. Hyperintensity on
diffusion-weighted imaging is helpful for differentiating spinal
epidermoid cysts from other cystic lesions. (3) Spinal mature cystic
teratomas are more common in children and adolescents and have no
special imaging characteristics. The final diagnosis depends on the
postoperative pathology. [7]Wilkins and Odom suggested three histological categories based on
microscopic features. Category A-simple cyst lined by epithelium on a
basement membrane with a thin wall of connective tissue.Category
B-cyst lined by epithelium with a wall containing tissues found along
the gastrointestinal tract or tracheobrochial tree.Category C-cyst
lined by epithelium with a wall containing ependymal and glial tissues
as an intrinsic part of the lesion.[8]
The treatment of SBC is mainly based on surgical resection.[9]For the SBC on the dorsal side of the spinal
cord, it can be completely removed. For cysts located on the ventral
side of the spinal cord, when the cyst wall and surrounding tissues are
seriously adhered, the focus should be on protecting the spinal cord.
Subtotal resection is also accepted.[10]According
to literature reports: the recurrence rate of subtotal resection is
about 11.6%. [11]As benign lesions, surgical
resection can often significantly improve symptoms and obtain a good
prognosis. Therefore, early detection and early surgical resection are
of great significance for prognosis.
Figure1:(A):Preoperative magnetic resonance imaging sagittal
sections,showing a hypointense on TWI1 and hyperintense on T2WI lesion.