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Sebaceous tumours are relatively rare tumours of the skin. Cutaneous
adnexal tumours with sebaceous differentiation vary from well-differentiated to poorly-differentiated varieties.
Recognition of these lesions is important:
-Patients with
multiple sebaceous tumours of the skin should be examined for other
visceral malignancies, eg. colonic, hematologial, urothelial, kidney,
endometrial etc - (Muir-Torre syndrome).
-Sebaceous carcinoma
is an aggressive tumour and must be distinguished from epidermal
tumours.
-Sebaceous
hyperplasia and Fordyce's spot / Montgomery's tubercle are not true
sebaceous neoplasm. Sebaceous hyperplasia is not associated with Muir-Torre
syndrome and must be distinguished from sebaceous adenoma which is
often associated with Muir-Torre syndrome.
There is an
increasing tendency to regard sebaceoma and sebaceous adenoma as part
of a continuum of benign tumours which some term simply as sebaceous
adenoma whereas others have suggested the term sebomatricoma. Pubmed
Link
Clues to diagnosis:
Presence of sebocytes or tubules resembling
sebaceous duct ; vacuolated cells with or without indentation of the
nucleus; ductal structures lined by crenulated corneocytes ; holocrine secretion; histochemical demonstration of
intracellular lipid .
MUIR-TORRE
SYNDROME:
Lancet Oncol.
2005 Dec;6(12):980-7
;
Cancer.
2005 Mar 1;103(5):1018-25.
Muir-Torre syndrome is
inherited as an autosomal dominant trait. This is a variant of the
hereditary non-polyposis colonic carcinoma syndrome and is due
to mutations of the mis-match
repair genes. The
criteria for diagnosis include presence of sebaceous neoplasm
(adenoma, sebaceoma and occasionally sebaceous carcinoma) internal
malignancy (eg. colorectal carcinoma). The sebaceous tumours are often
difficult to classify precisely. The tumours show marked cystic
changes. Recent studies suggest that immuno-histochemistry on the
sebaceous tumours for mismatch repair genes may identify patients with
Muir-Torre syndrome. Other visceral malignancies
have been reported in the larynx, genitourinary tract, ovary and
uterus. Keratoacanthoma, epidermal cysts and colonic polyps have
also been reported in this syndrome.
Case
Link
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Article link |
