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Adnexal tumours can differentiate towards the ductal and or/glandular
portion of the eccrine or apocrine glands. It is not possible to
distinguish on histological ground between the ductal portion of
eccrine and apocrine glands.
Traditionally most tumours
have been considered to show eccrine ductal differentiation.
Ackerman and colleagues have reclassified many of the traditional
eccrine tumours to apocrine categories.
Extensive sampling may
reveal foci of decapitation secretion in tumours classically regarded
as eccrine.
Some of the
glandular tumours reveal at least small foci of sebaceous or
follicular differentiation.
Sweat gland and
ductal differentiation: Characterized by formation of glandular/duct
structures and presence of intracytoplasmic glandular lumina.
True ducts and
intracytoplasmic lumina can be highlighted by their diastase-resistant
periodic acid-Schiff (PAS), epithelial membrane antigen (EMA) and
carcinoembryonic antigen positivity. Currently the diagnostic
utility of immunohistochemisty is doubtful.
Apocrine
differentiation: Characterized by decapitation secretion -
Ductal changes with apocrine snouting. |
