microcystic adnexal carcinoma

(redirected from syringomatous carcinoma)

microcystic adnexal carcinoma

A rare (circa 300 cases in the world literature) malignant skin appendage tumour, usually typed as a low-grade sweat gland carcinoma which occurs on the head and neck, and especially on the central face. It is locally aggressive and invades bone, muscle, blood vessels, cartilage, and nerves, but rarely metastasises. It presents as a clinical lesion averaging 3 cm2, but leaves an average post-surgical defect of 18 cm2, due to occult extension.

Epidemiology
Adults (median age 50; range 10 to 90).

DiffDx
Syringoma, desmoplastic trichoepithelioma, adenosuamous carcinoma, trichoadenoma, morphoeic BCC, metastatic breast carcinoma, small cell carcinoma.

Prognosis
It is locally aggressive, but rarely metastasises.

Aetiology
20–50% of patients have a history of therapeutic radiation with a 30-year average latency; UV light has also been implicated.
 
DiffDx
Desmoplastic trichoepithelioma, syringoma, trichoadenoma.
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References in periodicals archive ?
Syringomatous carcinoma (microcystic adnexal carcinoma; cases 42-44) represents a spectrum of infiltrative epithelial tumors that resemble syringomas.
The enigmatic eccrine epithelioma (eccrine syringomatous carcinoma).
The cases were histologically classified as follows: porocarcinomas (n = 41), syringomatous carcinomas (n = 3), ductal carcinomas (n = 8), adenoid cystic carcinomas (n = 5), and mucinous carcinomas (n = 3).
of Cases Tested) [Cytokeratin.sup.+] [CEA.sup.+] Porocarcinomas (38) 38/38 23/38 Syringomatous carcinomas (3) 3/3 3/3 Ductal carcinomas (8) 8/8 4/8 Adenoid cystic carcinomas (5) 5/5 5/5 Mucinous carcinomas (2) 2/2 2/2 Tumor (No.