| This is
a rare form of sweat gland carcinoma which has a striking resemblance to
the adenoid cystic carcinoma of the salivary glands.
Adenoid cystic carcinomas are regarded by some authors as apocrine in
origin.
Site:
Located on the scalp and on the chest. Rarely the tumour arises from the
skin of the eyelid.
Adenoid Cystic Carcinoma of the External Ear
;
Pulmonary
Adenoid
Cystic Carcinoma.
Microscopic features:
Images: (dermatopathology
cases)
- Cords of basaloid
cells arranged in a cribiform pattern.
- Focal tubular areas.
- Cystic spaces containing basophilic mucinous material.
- Perineural invasion is an important feature.
Immunohistochemistry:
Epithelial membrane antigen: Positive
CEA : sometimes positive
Cytokeratin, vimentin and S100 protein : focal positive staining
Differential diagnoses:
1.
Adenoid basal cell carcinoma: [Adenoid cystic carcinoma is characterized by:
Absence of retraction artefact , absence of contiguity with
the epidermis or hair sheaths , lack of peripheral palisading
of the nuclei, and occasional presence of central apoptotic
or even necrotic cells.
Pseudocysts
stain positively to Alcian blue and periodic acid-Schiff ].
2.
Primary cutaneous cribriform carcinoma:
Primary cutaneous cribriform
carcinoma: a rare apocrine tumour.J
Cutan Pathol. 2005
Sep;32(8):577-80.
Unlike most of the
sweat gland carcinomas, this tumour tends to recur locally
and rarely spreads to lymph nodes or distant organs. |