WHO Classification of Tumours 5th Edition Digestive System Tumours by WHO Classification of Tumours Editorial Board (z-lib.org).1

Oesophageal adenoid cystic carcinoma
Lam AK
Definition
Adenoid cystic carcinoma of the oesophagus is a malignant
oesophageal epithelial tumour of glandular differentiation with epithelial
and myoepithelial cells in true glandular and pseudoglandular
lumina arranged in cribriform, tubular, or solid architecture.
ICD-0 coding
8200/3 Adenoid cystic carcinoma
ICD-11 coding
2B70.Y & XH4302 Other specified malignant neoplasms of
oesophagus & Adenoid cystic carcinoma
Related terminology
None
Subtype(s)
None
Localization
These carcinomas are most often located in the middle third of
the oesophagus {2871,3779).
Clinical features
The most common symptom is dysphagia. Endoscopy and EUS
are used to confirm the diagnosis and determine the extent of
disease; the carcinoma appears as a protruding/elevated or
ulcerative lesion. Radiological evaluation (CT, MRI, or PET) is
used to determine the clinical staging of the carcinoma.
Epidemiology
Oesophageal adenoid cystic carcinoma is uncommon, with
only slightly more than 100 reported cases {2871,3779,2578}.
Approximately half of these cases are from Asian populations
(2871,3779,1118). Adenoid cystic carcinoma constitutes about
0.1% of all oesophageal malignancies (1525). It is more common
in men, with an M:F ratio of 3.5:1 to 5:1 (2871,3779,2578),
and it most often occurs in the seventh decade of life (mean
patient age: 65 years; range; 36-84 years) (2871,2578).
Histopathology
Adenoid cystic carcinoma consists of a mixture of epithelial
and myoepithelial cells in a variety of cribriform, tubular (glandular),
or solid patterns. The cribriform pattern is characterized
by tumour cells forming cystic lumina, which contain
either basophilic glycosaminoglycans that are Alcian bluepositive
(true glands) or hyalinized basal lamina material that
are PASD-positive (pseudoglands). In both the cribriform and
tubular patterns, the glands are lined by inner epithelial and
outer myoepithelial cells, whereas the solid pattern shows no
lumina. Perineural infiltration and lymphovascular permeation
are common (2871). Adenoid cystic carcinoma can coexist
with squamous cell carcinoma or with dysplasia / carcinoma in
situ (535). The myoepithelial cells in adenoid cystic carcinoma
are positive for p63, S100, SMA, and calponin. The epithelial
cells are positive for cytokeratin, CEA, and KIT (CD117)
(3779,3274). Basaloid squamous cell carcinoma may be considered
in the differential diagnosis, because it often has a
pseudoglandular pattern similar to that of adenoid cystic carcinoma
(1890). However, adenoid cystic carcinoma rarely has
squamous cells, central necrosis, or prominent mitotic figures,
and basaloid squamous cell carcinoma is negative for SMA
and S100.
Cytology
The cytological appearance of adenoid cystic carcinoma arising
in the oesophagus has not been documented in the literature.
Diagnostic molecular pathology
Not clinically relevant
Etiology
Unknown
Pathogenesis
Unknown
Macroscopic appearance
Macroscopically, adenoid cystic carcinoma is either protruding
or ulcerative (2871,3779,1118). In the early stage, it often located
in the submucosa, with the mucosa still intact. The lesions have
a mean size of 56 mm (867), but they can be highly variable in
size (3714,2083).
Fig. 2.15 Oesophageal adenoid cystic carcinoma. The cribriform pattern.
44 Tumours of the oesophagus
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