Will MAC be back?
BACKGROUND
Microcystic adnexal carcinoma (MAC) was first described as a specific entity in 1982 by Goldstein et al. MAC is a very aggressive tumour, displaying locally invasive tendencies with perineural invasion. For this reason previous studies have suggested that Mohs micrographic surgery is a superior technique in establishing clear margins of excision. However, there is no evidence to suggest that standard local excision is less effective in achieving tumour clearance or a more favourable outcome.


METHODS
All patients with MAC were identified from the pathology database. All patients who had undergone local excision were reviewed and included in the study. Histopathology was reviewed by dermatopathologists.


RESULTS
We reviewed the outcome of 17 patients treated with local excision. Eleven were female and six were male with a mean age of 70 years, and a mean follow up of 30 months. Two patients in this series experienced recurrence after standard local excision. The mean lateral and depth margins were 7.69 mm (range 0.2-21) and 4.66 mm (range 1-14.5), respectively. Recurrence occurred in two out of three patients who had lateral clearance margins of less than 4 mm. These two patients had evidence of perineural invasion on histopathology.


CONCLUSIONS
In the present study, standard local excision is shown to be effective in tumour clearance for MAC with no recurrences provided there are lateral margins of at least 4 mm. However, a longer period of follow up is required because of the very aggressive locally invasive nature of the tumour.
Salerno
Stephen
S
Plastic Surgery Unit, Frankston Hospital, Monash University, Melbourne, Victoria, Australia. salerno@netspace.net.au
Terrill
Patricia
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012189:Retrospective Studies; D013544:Sweat Gland Neoplasms / Q000473:pathology / Q000601:surgery*; D018252:Syringoma / Q000473:pathology / Q000601:surgery*