Open Journal of Obstetrics and Gynecology, 2012, 2, 247-249 OJOG
http://dx.doi.org/10.4236/ojog.2012.23051 Published Online September 2012 (http://www.SciRP.org/journal/ojog/)
Melanosis of the vulva: A long-term follow-up from
Brisbane, Australia
Ian S. C. Jones
Women’s and Newborn Services, Royal Brisbane and Women’s Hospital, Brisbane and University of Queensland, Herston, Australia
Received 14 May 2012; revised 21 June 2012; accepted 4 July 2012
ABSTRACT
Object: To determine if vulvar melanosis progressed
to melanoma over a period of 20 years or more.
Methods: In 2010 the hospital records from the Royal
Brisbane Hospital Vulvar Clinic between 1976 and
1988 were reviewed and cross checked with the state
wide Queensland Centre for Gynaecological Cancer
(QCGC) data base to determine if any patient had
been lost to follow up and subsequently developed a
vu lvar melanoma. Data collected were stored and ana -
lysed using the computer software Statistical Package
for the Social Sciences (SPSS) 11.0. Results: None of
the 12 patients developed vulval melanoma in the
years up to 2010. Conclusion: In this small group,
followed for more than 20 years, melanosis was not a
precursor of melanoma. One patient, who attended
the Vulvar Clinic but was not included in this mela-
nosis study, was found to have co-existing melanosis
well away from her melanoma in situ and malignant
melanoma at presentation. It was not possible to de-
termine if these findings represented a progression of
the benign to malignant. Biopsy of abnormal hyper
pigmented vulvar skin is recommended. Current know-
ledge suggests that vulvar melanosis is a benign con-
dition but to be on the safe side follow up of all hyper
pigmented vulval lesions to detect early malignant
change is recommended.
Keywords: Vulva; Pigmented Epithelial Disorders;
Features; Follow-Up; Malignancy
1. INTRODUCTION
Variations in melanin pigmentation of the vulval skin are
considerable within and between different races, age and
in relation to hormonal status [1]. Causes of hyperpig-
mentation due to melanin excess include lentigo; melanin
incontinence with melanin within macrophages in the
upper dermis following inflammation; adult vulval acan-
thosis nigricans which affects the entire vulva; pseudo-
acanthosis nigricans of flexural skin in obese and darkish
skinned people and following fixed drug eruption. The
main concern is distinguishing between benign lesions
and malignant melanomas of the vulva. Vulval skin bi-
opsy will distinguish between areas of hyperpigmenta-
tion due to melanin, melanoma in situ and malignant
melanomas. The macroscopic and histological features of
normal vulval skin during life have been described else-
where [2].
The aim of this paper is to review the clinical features,
look for predisposing factors and determine the long
term outcomes for women who presented to the Vulval
Disease Clinic at the Royal Brisbane Hospital between
1976 and 1988 with vulvar melanosis and determine if
any lesion progressed to a melanoma.
2. METHODS
All patients presenting to the Vulval Diseases Clinic be-
tween 1976 and 1988 had their clinical and pathology
details recorded on proforma cards in addition to the
hospital records. In 2010 the hospital records were re-
viewed and the proforma cards up dated. Records were
cross checked with the state wide Queensland Centre for
Gynaecological Cancer (QCGC) data base to determine
if any patient had been lost to follow up and subse-
quently developed a gynaecological malignancy, espe-
cially vulval malignant melanoma.
Data from the up-dated proforma cards were stored
and analysed using the computer software Statistical
Package for the Social Sciences (SPSS) 11.0.
Ethics approval for the review of case records was ob-
tained from the Clinical Research Ethics Committee of
the Royal Brisbane and Women’s Ho spital.
3. RESULTS
Of 361 patients seen at the clinic between 1976 and 1988,
12 (all Caucasian) were found to have vulvar melanosis.
Patient age at presentation is shown in Tabl e 1, with the
majority being aged 50 or more. The three patients under
50 years of age were all menstruating regularly. All but

I. S. C. Jones / Open Journal of Obstetrics and Gynecology 2 (2012) 247-249 248
Table 1. Age at time of diagnosis.
Age range Melanosis
n = 12 Melanoma n = 42
20 - 29 0 1
30 - 39 1 0
40 - 49 3 8
50 - 59 2 7
60 - 69 3 6
70 - 79 1 11
80 - 89 2 8
90 - 99 0 1
one patient were parous. Three patients presented with a
symptomatic vulv ar dystrophy (histo ry of pruritus vu lvae
for between 3 months and 5 years), one patient presented
with pruritus vulvae du e to vulval intra epithelial n eopla-
sia (VIN 3) remote from her vulvar melanosis, and one
presented with a vaginal discharge. The other patients
were referred for review of their vulval pigmentation
noted at routine gynaecological examination. The highest
incidence of melanosis was found in post menopausal
patients (67%), but can o c cur before this time.
The anatomical location of the vulvar melanosis ap-
peared to “favour” the labia minora (8 cases) and introi-
tus (2 cases). The lesions were of variable size (1 - 5 cm),
flat and the affected skin had a normal texture. No pa-
tients had clinical groin lymphadenopathy. In an attempt
to determine if there were any predisposing features for
the development of vulvar melanosis coexisting medical
conditions were sought. Various conditions were found in
11 patients (Table 2), but apart from the possibility of
skin irritation associated with the presence of a vulvar
dystrophy being a cause rather than an association, no
predisposing features were found.
No treatments were used to manage the vulvar mela-
nosis and no patients developed malignant melanoma of
the vulva between 25 and 33 years after presenting to the
Vulval Diseases Clinic. However, another patient aged
75 who attended the Vulvar Clinic but not included in
this melanosis study, was found to have co-existing
melanosis well away from her melanoma in situ and ma-
lignant melanoma at presentation in 1977.
QCGC data from the beginning of data collection in
1985 to 2009 record 42 patients with vulval melanoma of
whom 20 died of their disease and 6 died of unrelated
causes. Their ages at diagnosis ranged from 25 to 92
years and this data was compared with the ages of diagno-
sis for the melanosis cases (Tab le 1 ). Treatment regimes
for the melanoma group included wide local excision;
partial vulvectomy; radical vulvectomy and bilateral
Ta b le 2 . Other medical disorders associated with non-neoplas-
tic epithelial disorders.
Patient identifierOther medical conditions prese nt
1 Liver disease, HBP
2 Vulvar lichen sclerosus, non-Hodgkins
lymphoma, endometrial carcin oma stage 3B
3 Micro-invasive cervical carcinoma
4 Diabetes, renal calculi, VIN 3
5 Vulvar lichen sclerosus, pernicious anaemia,
depression
6 Mixed vulvar dystrophy, CVA, depression
7 BCC nose, r enal calculi, HBP
8 Cervical carcinoma with radiotherapy treatment
9 Gout, brother with melanoma
10 Nil recorded
11 BCC scalp, scleroderma, anxiety
12 BCC ear
groin dissection; radical vulvectomy, vaginectomy and
groin dissection; pelvic lymphadenectomy and surgery
plus radiation therapy.
4. DISCUSSION
The aims of this paper were to determine if vulvar me-
lanosis progressed to melanoma over a period of 20 years
or more; review the clinical features; determine if there
were any predisposing features for the development of
melanoma and determine the long term outcomes for
women who presented to the Vulvar Disease Clinic with
vulvar melanosis. The need for a long term follow-up
study of melanosis was because it is unknown if melano-
sis could be a forerunner of melanoma, and if it was how
long such changes take to occur. Ta b l e 1 shows the age
distribution for p atients presenting with vulval melanosis
(36 to 85 years) compared with vulval melanoma (25 to
92 years), which because of advanced age when discov-
ered suggests some patients take a considerable time for
a melanoma to develop. Even with a 30 year follow up
this may not be long enough for some patients to develop
vulvar melanoma.
The prevalence of vulval melan osis is unknown. Large
melanotic lesions of the vulva are uncommon [3,4]. A
study of 301 new patients presenting to a gynaecology
practice over a one year period found 31 (10%) had pig-
mented lesions on the vulva, six (2%) had diffuse hyper
pigmentation of the vulva and seven (2%) had vulval
nevocytic nevi [5].
The most common cause of vulval hyperpigmentation
due to melanin (which must be distinguished histolo-

I. S. C. Jones / Open Journal of Obstetrics and Gynecology 2 (2012) 247-249 249
gically from haemosiderin), is lentigo [1]. Lentigo, also
known as lentigo simplex, is a benign pigmented prolix-
feration of epidermal or mucous membrane melanocytes
which form smooth, non-infiltrating dark brown lesions
on the labia minora and introitus. Lentigo is of unknown
aetiology and pathogenesis and lesions do not usually
exceed one cm in diameter [1]. However, in the current
study melanosis varied in size from one to five cm.
Sison-Torre & Ackerman [6] described eight women
with extensive pigmentation of the vulva and used the
term melanosis of the vulva. Th ey show ed on b iopsy that
these lesions were benign and analogous to lentigo. Len-
tigines may resemble junctional naev i, but do not exhibit
cytological atypia [7]. This raises the question could
vulvar melanosis be the big sister to lentigo simplex with
the difference being size alone?
Vulval pigmentation depends on the presence of cells
containing melanin [8]. The detection of such pigmen-
tation can be obscured by dermal vascularity, the thick-
ness of overlying skin and the position of the melanin
containing cells within the skin. The distribution of pig-
mentation of dark-skinned races is concentrated in the
basal layer, but varies considerably in amount. Micro-
scopic patches of melanin pigment were found in almost
80 per cent of 35 Caucasian women at post mortem when
there was no evidence of macroscopic hyper pigmenta-
tion [8].
The differential diagnosis of vulval hyperpigmentation
is lentigo; junction al naevi; following inflammatory con-
ditions like lichen planus; adult vulval acanthosis nigri-
cans which affect the entire vulva and may be associated
with an adenocarcinoma or occasionally lymphoma or
epithelial carcinoma; the pseudo-acanthosis nigricans of
flexural skin in obese and darkish skinned people (now
thought to be related to insulin resistance) and following
fixed drug eruption from for example, sulphonamides.
The most important risk for these patients is the possibi-
lity of misdiagnosing a malignant melanoma. Making a
clinical diagnosis based on the anatomical site and skin
texture is not foolproof, hence biopsy and histological
diagnosis is recommended. Even in the case of the 75
year old woman who presented with co-existing melano-
sis, melanoma in situ and malignant melanoma, it was
not possible to determine if these findings represented a
progression from the benign to malignant. The impor-
tance of follow up of all hyper pigmented vulval lesions
to detect early malignant change is stressed.
Variations in terminology to describe benign hyper-
pigmentation due to the presence of melanin include
vulvar melanosis, idiopathic lenticular mucocutaneous
pigmentation and genital lentiginosis [1]. However vul-
var melanosis or its other name melanosis vulvae seem to
be terms used by the majority when referring to this con-
dition.
5. CONCLUSION
The difficulty in finding a suitable term for benign hy-
perpigmentation of vulval skin conditions remains. To
reliably diagnose a hyper pigmented vulval lesion a
histopathology diagnosis is required. Current knowledge
suggests that vulvar melanosis is a benign condition but
to be on the safe side follow up of all hyper pigmented
vulval lesions to detect early malignant change is re-
commended.
6. ACKNOWLEDGEMENTS
Thanks to the Queensland Centre for Gynaecological Cancer (QCGC)
staff for their assistance in providing data and checking their data on
the current study patients.
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