Punch biopsies are not effective in differentially diagnosing for EMPD and as a result, excisional biopsies of the affected area are taken [XX]. A positive test result for EMPD shows increased numbers of large polygonal cells with a pale bluish cytoplasm, large nucleus and nucleolus, infiltrating the epidermal layer. These neoplastic cells can be found singly scattered or can appear in groups called nests.Paget cells contain mucin and cytokeratins which can be used in the diagnosis of EMPD [8] MUC5A2 is found in EMPD of the vulvar and male genitalia regions whereas MUC2 is expressed in perianal EMPD. Loss of MUC5A2 can indicate an invasive spread. Immunohistochemistry (IHC) can be used to determine whether EMPD is either primary or secondary. Primary EMPD tests positive for CK7 but negative for CK20, whereas secondary is positive for both. Lack of positivity for hormone receptors and HER2 protein is overexpressed meaning that the cells are dividing rapidly and can be indicate an aggressive and more recurrent disease. Classification
Primary EMPD is of cutaneous origins and is found within the epidermis or the underlying apocrine glands. Although it is limited to the epithelium, it has potential to spread and progress into an invasive tumour, metastasising to the local lymph nodes and distant organs. This form of EMPD is not associated with an adenocarcinoma.The secondary form results due to an underlying adenocarcinoma spreading to the epidermis.
Outcomes
The rate of progression varies significantly from person to person.There is not good data on outcomes; it appears that APBD likely leads to earlier death, but people with APBD can live many years after diagnosis with relatively good quality of life. Epidemiology
The prevalence is unknown; about 70 cases had been reported in the medical literature as of 2016. As of 2016 the largest set of case studies included 50 people; about 70% of them were of Ashkenazic Jewish descent. Society and culture
A person with APBD named Gregory Weiss created a foundation, the Adult Polyglucosan Body Disease Research Foundation, to fund research into the disease and its management. Research directions
In 2015 the first transgenic mouse that appeared to be a useful model organism for studying APBD was published. References

 This article incorporates public domain material from Adult polyglucosan body disease. United States Department of Health and Human Services. == External links ==