Discussion
Papillary cystadenoma usually occurs in salivary gland tissues such as
oral cavity, head and neck, and has a certain risk of malignant
transformation. Some reports have shown that this type of tumor can also
be distributed in other parts of the digestive tract, such as lip,
tongue, nasopharynx, orbit, zygomatic part, larynx, esophagus,
gastroesophageal junction, cardia, gastric antrum, transverse colon,
rectum, anus and so on. By reviewing the relevant literature, we
analyzed the characteristic of gastrointestinal papillary cystadenoma.
The clinical and pathological features were summarized.
Papillary cystadenoma occurring in the digestive tract is extremely
rare, and can happen in any part of the digestive tract. At present, the
pathogenesis is not clear. Some literatures believe that it may be
related to congenital ectopic metaplasia of salivary gland[1]. The clinical manifestations are obviously
related to the location of the lesions. Among which the cases occurred
in the larynx, esophagus, gastroesophageal junction, cardia and other
places can be treated for dysphagia, choking feeling, acid regurgitation
and other symptoms [2-4]; When the cases occurred
in the transverse colon, rectum, anus and other lower digestive tract
can be treated for bleeding, abdominal pain, anal foreign body sensation
and other symptoms [5-8]; Some cases such as the
tumor was in the gastric antrum may have no obvious clinical symptoms[9]. Endoscopic presentation of the disease are
submucosal protuberant lesions or polypoid protuberant lesions.
Endoscopic ultrasonography may showed hypoechoic lesions confined to the
mucosa or submucosa, with diameters ranging from 1 to 2 cm. Clinically,
it needs to be differentiated from gastrointestinal stromal tumor,
leiomyoma, neuroendocrine tumor, cyst, lipoma, heterotopic pancreas and
other diseases [10].
The pathological features were [11-13]: the tumor
was round in shape, with the largest diameter of 1-3cm, nodular on the
surface and clear boundary with surrounding tissues. The section is
white or grayish white, solid or with different sizes of cysts. There
are mucoid substances in the cysts, and small papillae can be seen in
the larger cysts. Microscopic examination showed that the tumor was
composed of mucous cells and cuboidal cells. The two kinds of cells are
staggered. The mucus cells were columnar or cuboidal, with round
nucleus, located at one end of the cells. They were small in size,
stained deeply, and stained lightly in cytoplasm. The cytoplasm of
cuboidal cells is eosinophilic, the boundary is not clear, the nucleus
is round or oval, the volume is large, and the staining is light. In
papillary cystadenoma, the glandular cavity is extremely enlarged into a
cystic cavity, which is lined by columnar or cuboidal glandular
epithelial cells, and many proliferating papillae protrude into the
cavity. The epithelial cells of the nipple are high columnar, with
secretion. There are connective tissue fiber bundles in the center of
the nipple, without lymphoid tissue. There are eosinophils in the
capsule.
Currently, the understanding of the nature of papillary cystadenoma is
not consistent. Most researchers consider it to be benign tumor but
locally invasive. Some cases showed severe atypical hyperplasia, or
highly differentiated papillary carcinoma and papillary
cystadenocarcinoma due to abundant papillary proliferation of ducts. Or
abominable mucoepidermoid carcinoma [14-17].
Therefore, the disease has a certain risk of malignant transformation,
which should be paid attention to by clinicians.
At present, papillary cystadenoma should be treated with surgery.
Endoscopic submucosal dissection and endoscopic submucosal mass removal
(ESD, ESE) is recommended for papillary cystadenomas of the digestive
tract. Patients were sent to regular endoscopic follow-up after
diagnosis by pathology and immunohistochemistry after surgery. The were
no complications or recurrence case reported after the endoscopic
resection or surgical resection in benign cases.
Therefore, based on this case and a review of the relevant literature,
we concluded that papillary cystadenoma can occur in any part of the
digestive tract and lacks specific clinical and endoscopic
manifestations. And the diagnosis of papillary cystadenoma should be
confirmed by pathological examination after complete resection of the
lesion by endoscopic surgery or surgical resection. Although the
incidence of papillary cystadenoma of the digestive tract is extremely
low, it has a certain risk of malignant transformation, so it needs to
be paid more attentions to by endoscopologists and pathologists.