Asmaa N. Abdullah *
Hadeel A. Yasseen**
Hassanain H. Khudier**
Ali Ibrahim **
* Al-Yarmook Teaching Hospital.
** Department of Anatomy, School of Medicine, University of Sulaimani
Identification of Glandular differentiation in appendiceal carcinoid tumor- A study in Sulaimania city
Carcinoid tumor of appendix is the most common appendiceal tumor. Both the classical and mixed carcinoid
tumor could be identified using the routine H&E stain. Using additional stains such as Periodic Schiff stain,
Alcian blue and cytokeratin 20 (CK20) stain have been used to detect these appendiceal mixed (glandular)
To identify glandular differentiation and mucin production in appendiceal carcinoid tumors by using special
stains and immunohistochemistry.
Patients and Methods
This retrospective case-control study was carried out in research laboratory of Pathology Department/School
of Medicine. All pathological reports of patients with appendiceal carcinoid tumor were collected from the
laboratory of pathology-Sulaimani Teaching Hospital over the period of six years (from the 1st of January
2006 to the 31st of December 2011), patient’s age, sex and histopathological diagnosis were documented.
Fifteen cases (out of 10533 appendectomies) were divided into 2 groups: classical (insular) and mixed (insular
with mucinous differentiation). Formalin-fixed, paraffin-embedded, 4- micrometer- thick sections were
immunostained with CK20 using HIER-LSAB method. All cases were stained with Alcian blue stain for
acidic mucin detection, and PAS stain for neutral mucin detection within the carcinoid tumor. Then the results
of H&E stain, immunostain for epithelial differentiation and the special stains for mucin production were
evaluated together and compared with similar studies.
The carcinoid tumor is more common in females with a peak age range of 21-30 years, mean incidence 0.14%
for fifteen cases of carcinoid tumors. Carcinoid tumor in patients above 50 years is usually mixed type. PAS
and Alcian blue stains are of no statistically significant correlation with glandular differentiation, while CK20
has statistically significant correlation with glandular differentiation but staining intensity is variable.
H&E is the main method for the identification of glandular differentiation of carcinoid tumor, however CK20
has important value to assist the diagnosis, while mucin stains have limited value in the identification of
glandular differentiation of carcinoid tumor.
Keywords: Appendix, mixed carcinoid Tumor, PAS stain, Alcian blue, CK20.