Discussion
MAC mostly occurs in the centrofacial region, in which lips include
about 50% of cases (8).
The other most common involved sites are periocular area, nose,
nasolabial fold, cheek, scalp, and chin. Although MAC is mostly
considered as a neoplasm of the head and neck region; the axilla,
antecubital fossa, buttocks, foot, and chest are the other affected
areas which have been reported in the literature (2,4,12,13).
MAC is assumed to be a non-metastatic tumor; however, Yugueros et al
reported 55 patients affected to sweat gland carcinomas, in which, 17 of
them declared a history of MAC which was treated by excisional surgery
and radiotherapy (14). Also Lei et al. reported lymph node involvement
in the contralateral region of neck in a patient with MAC, which had
performed radiation and surgery as treatment 22 years earlier. They
proposed that it is more possible to be the result of direct extension
via perineural path rather than lymphatic spread (4,15). The
supraorbital nerve can be invaded by the lesions presenting in
periorbial area, particularly on the eyelid or eyebrow.
Although no defenitive cause has been found yet, some studies have
reported radiation therapy, chronic sun exposure, and immuno-compromised
status as predisposing factors for MAC (2,3,8,16).
History of prior radiation has been reported in 8–12% of the cases
(17-19); also lesions in atypical sites, including the neck, have been
seen in patients with a history of radiation on the affected area
(20,21).
It is proposed that taking immuno-suppressive drugs may develop MAC
lesions (22). A chronic lymphocytic leukemia (CLL) patient with scalp
MAC was reported by Carroll et al. (23); as it has been reported in
immuno-compromised patients several times (22-24).
In order to have a successful treatment, an accurate diagnosis is
necessary. Clement et al. found that MAC can be easily misdiagnosed
(25). As mentioned before, the clinical presentation of MAC could be
mistaken for basal cell carcinoma (BCC), squamous cell carcinoma, cyst
or scar, particularly when a biopsy is not representative of the entire
lesion. Failure to obtain a proper biopsy sample could also result
misdiagnosis, due to the infiltrative nature of the lesion.
We can not evaluate the treatment options of MAC properly, due to the
rarity of the disease and lack of studies with long-term follow-up of
the patients in the literature. As recurrence of MAC is not predictable,
exision surgery with clear margins and minimum pathologic atypia can aid
to decrease the rate of recurrence (2).
The most common utilized treatment modalities for MAC include wide local
excisional surgery (WLE), Mohs micrographic surgery (MMS) and
radiotherapy. Recurrence has been reported in using every type of
treatment modalities above, even in patients with clear tumor margins
(3,8, 15,26).
Regardless of the method chosen, complete removal of the tumor on its
first occurrence is ideal as recurrent lesions are much more difficult
to manage.
MMS offers the highest probability of clear surgical margins as it can
detect subclinical extension while providing maximum tissue sparing
(2,27).
Determining true margin status in the subset of MAC patients with
perineural invasion (PNI) treated with surgical techniques can be
problematic. Cutaneous carcinoma with PNI manifestation, behaves
aggressively and increased rate of recurrence with wide extension have
been observed. It has been reported in 17.5–59% of MAC patients (27).
WLE is another alternative, in which margin detection depends mainly on
the histologic technique hired by the pathologist.
It is strongly recommended to perform complete excisional surgery with
clear margins with long-term follow-up, because of high rate of
recurrences; as it can recur even several years after the surgery
(2,28). Also we should take surgical margins wider than clinical margins
due to the infiltrative growth pattern of the tumor. Recurrence rate of
WLE is about 17% to 60%, as reported in studies (2,8,29,30).
It is still challenging to define the role for definitive or adjunctive
radiotherapy in, because of the rarity of disease and the uncommon use
of radiotherapy for managing the disease. The majority of studies
reported unclear details about hired techniques of radiotherapy for MAC
lesions. Differences in radiotherapy techniques and sequencing also make
it difficult to draw conclusions. There is evidence that radiotherapy
can transform the MAC lesion into a new highly aggressive form,
according to its clinical and histological features (31,32).
MAC has also been reported as a radiogenic secondary malignancy (33). 16
of 84 published MAC cases in the literature, have declared a history of
prior exposure to radiations, with 19.05% incidence
(8,17,19,28,31,34-44).
As the rate of MAC recurrence after monotherapy with radiotherapy is
high (1,8,45), it is not commonly suggested to use radiotherapy as
definitive monotherapy for patients with MAC. But as adjuvant therapy,
it may be useful in subset of patients who have undergone WLE or MMS
without achieving a tumor free margin and are at high risk of
recurrence. Also it can be considered as treatment in patients who avoid
to perform WLE or MMS, because of the disfiguring facial defects of
surgery. Elderly patients may also be a good candidate for radiotherapy,
particularly in those whose comorbidities make them poor surgical
candidates.
The knowledge about hair transplantation is growing every day. In 1959,
Dr. Orentreich developed it for the first time. He applied it as a
therapeutic procedure on a patient suffering from androgenic alopecia
(46).
Hair transplantation is used for covering the features of hair loss and
it has become one of the main popular procedures in cosmetic field
(particularly scars) now with satisfactory results (47).
Follicular unit transplantation (FUT) and follicular unit extraction
(FUE) are common techniques hired for hair transplantation. In FUT
technique, a band-shaped tissue of occipital region is used as donor,
which results a linear scar. To avoid its complications, including
scarring, FUE technique was introduced, in which, small units of hair
follicles are harvested (47).
Osman et al. performed hair transplantation on the cleft lip area scar.
They hired fat grafting procedure on twenty patients suffering from scar
and alopecia. Then hair transplantation was performed three months after
fat injection. After a one-year period of follow-up, patients declared
noticable high level of satisfaction (48).
Also Soyeon et al. evaluated the results of hair transplantation for
scar management in 25 cases (of 23 patients), in which burns, operation,
and trauma resulted scar with hair loss on the scalp and the face
(eyebrow, lip, and eyelid). After a 6 months period of follow-up,
satisfactory report from hair follicle transplantation procedure was as
excellent (44.4%), good (38.9%), fair (11.1%), and poor (5.6%) (49).
Transplanting the hair follicles on a tissue with scar is so difficult,
due to the poor blood supplement and tenacity of the scar tissue. Also,
a higher rate of success and favorable results is seen in patients with
burned scar rather than incision scars, due to the deeper depth of
incision scars (49).
So, we should always warn the patients that choosing hair follicle
transplantation procedure for scar management, can be accompanied by
secondary (or more) operations, for better cosmetic result.