A memorable patient
Clinical and Experimental Dermatology
An unusual onset of agminated Spitz naevi in an adult patient
N. R. Adler,
J. W. Kelly,
J. P. Dowling,
and V. J. Mar
Victorian Melanoma Service and
Department of Anatomical Pathology, Alfred Hospital, Melbourne, Victoria, Australia;
School of Public Health and
Preventive Medicine, Monash University, Melbourne, Victoria, Australia;
Department of Dermatology, St Vincent’s Hospital, Melbourne, Victoria, Australia;
Skin and Cancer Foundation, Carlton, Victoria, Australia
A 31-year-old Caucasian man presented with multiple
papules on his right thigh, which had erupted
abruptly over several months prior to his presentation.
The patient had no relevant medical history.
On physical examination, multiple, dome-shaped,
pink and brown papules were seen, clustered on the
patient’s right posterior thigh, with a smaller cluster on
the volar surface of his left forearm (Fig. 1a,b). Both
clusters occurred on a background of normally pig-
mented skin. The papules displayed a diverse dermo-
scopic appearance. There was no lymphadenopathy.
Two papules were excised from the right thigh. His-
tological examination of both revealed features of a
compound Spitz naevus, consisting of large epithelioid
nested and single melanocytes with abundant cyto-
plasm. Small nests and single cells showed limited dis-
array in the variably acanthotic epidermis, with
occasional Kamino bodies. There were no dermal
mitoses, and the dermal melanocytes displayed no
maturation (Fig. 2).
Management consisted of 6-monthly clinical and
dermoscopic examination, aided by initial total body
photography to serve as a comparative reference,
without further surgical intervention. Twelve months
following the patient’s initial presentation, one new
papule had appeared, which is being monitored.
Spitz naevi are benign melanocytic proliferations
with distinct histopathological characteristics.
some cases, it can be difﬁcult to differentiate
histopathologically Spitz naevi from malignant
The vast majority of Spitz naevi present as solitary
lesions, and development of multiple Spitz naevi is
rare, with < 80 cases reported in the literature.
According to the most widely accepted classiﬁcation
system, multiple Spitz naevi can be divided into two
variants according to their pattern of appearance:
eruptive disseminated (widespread) and agminated
The eruptive disseminated variant most often pre-
sents with tens to hundreds of polymorphic papules
diffusely distributed over the extremities, trunk and
face with sparing the acral surfaces.
Spitz naevi, which are more common in children,
have been reported to occur on a background of
hyperpigmented, hypopigmented or normally pig-
Both agminated Spitz naevi and multi-
ple primary melanomas have been reported to arise
within a speckled lentiginous naevus.
In this con-
text, the difﬁculty in differentiating melanoma from
Spitz naevus is compounded. In rare cases, agmin-
ated Spitz naevi may also present in a dermatomal
The aetiopathogenesis of multiple Spitz naevi is
largely unknown. Previous authors have attempted to
identify causal factors, which have often related to
However, these causal factors
appear to be speculative only.
The genetic alterations underlying multiple Spitz
naevi are not well established. Mutations in BRAF and
RAS oncogenes have been reported in solitary Spitz
but these somatic mutations appear to be
absent in tumours of patients with multiple Spitz
Unlike solitary Spitz naevi, surgical excision of mul-
tiple naevi is often impractical. Reassuringly, there
have been no reported cases of malignant transforma-
tion in patients with multiple Spitz naevi.
management of multiple Spitz naevi consists of
Correspondence: Dr Nikki R. Adler, Victorian Melanoma Service, Alfred
Hospital, Melbourne, Victoria, Australia
Conﬂict of interest: the authors declare that they have no conﬂicts of
Accepted for publication 23 May 2017
ª 2017 British Association of Dermatologists Clinical and Experimental Dermatology (2018) 43, pp363–365