ARTICLE
Auteur(s) :, Rudolf HAPPLE*, Stefan
HÖRSTER
Department of Dermatology Philipp University of Marburg
Deutschhausstraße 9 D-35033 Marburg Germany
*R. Happle, Fax: (+ 49) 6421-286-2902. E-mail:
happle@med.uni-marburg.de
accepté le 11 Juin 2004
In 1997, nevus psiloliparus was delineated as a new
clinico-pathologic entity [1]. The name was derived from the Greek
words psilos = hairless and
liparos = fatty, describing the distinguishing
features of the disorder. Histopathologically, absence of mature
hair follicles and presence of orphaned arrector pili muscles and
excess fatty tissue were noted.So far, nevus psiloliparus has
always been found to be associated with neurological, skeletal or
ocular defects in the form of encephalocraniocutaneous lipomatosis
[1]. However, already in 1997 we argued that nevus psiloliparus
should likewise occur in an isolated form although such cases had
so far not been reported. Here we present two such cases and
describe additional histopathological features of this nevus.
Case reports
Case 1: A 4-year-old girl was presented by her parents for
evaluation of a hairless patch of her scalp noted since birth. The
girl was otherwise healthy. There was no family history of a
similar skin lesion. Physical examination showed an oblong
10 × 3.5 cm area with a smooth, slightly yellowish
surface on the left side of her scalp (( Fig. 1 )).
Histopathological examination of a biopsy showed absence of mature
hair follicles and presence of some immature infundibular
structures filled with hyperkeratotic plugs in a rather thin
epidermis (( Fig. 2 )). In the mid
dermis orphaned arrector pili muscles were noted in a horizontal
“Indian file” arrangement, whereas the lower portion of the dermis
contained arrested hair bulb anlagen in the form of globular
aggregations of fibroblasts (( Fig. 3 )). Moreover,
aberrant lobules of fatty tissue were noted in the lower portion of
the dermis, sometimes in proximity to the hair bulb anlagen ((
Fig. 2 )).
Sebaceous glands were absent, whereas eccrine glands were present
in normal size and numbers. The subcutaneous fatty tissue was
abundant and devoid of hair follicles.
Pediatric examination for ocular or neurological abnormalities
gave normal results. The parents did not give permission for
examination of the brain by imaging techniques. During a follow-up
period of 2 years, the child developed normally.
Case 2: A 5-month-old girl was presented by her parents
for evaluation of a bald area on her scalp. The hairless patch had
been noted at birth. The infant was otherwise healthy, and there
was no family history of a similar skin lesion. Physical
examination showed a round hairless plaque at the crown of the head
(( Fig. 4
)). The lesion was rather soft when palpated and the surface of the
somewhat elevated lesion was entirely smooth and did not show an
orange-like structure as usually seen in a sebaceous nevus.
Histopathological examination showed immature hair follicles
including arrested bulbar anlagen. In the mid dermis numerous,
somewhat hyperplastic, orphaned arrector pili muscles (( Fig. 5 )) as well
as sebaceous glands and eccrine glands were noted. The thickness of
the dermis appeared to be decreased, whereas the underlying fatty
tissue appeared to be increased.
Pediatric examination of the eyes and the central nervous system
did not indicate any abnormality. We proposed a sonographic
examination of the brain but the parents decided to postpone this
measure. During a follow-up period of 2 years, the girl developed
normally and did not show any unusual clinical features. During
this time the hairless patch remained unchanged.
Discussion
In these two girls a diagnosis of nonsyndromic nevus psiloliparus
is most likely. The presence of arrested mesodermal hair bulb
anlagen is a new finding within the spectrum of histopathological
features of this type of nevus.
Nevus psiloliparus has so far been disregarded as a cutaneous
entity [1]. It has repeatedly been described as a nameless skin
lesion being associated with encephalocraniocutaneous lipomatosis
[2-4]. However, in analogy to other nevi that may occur in
association with extracutaneous anomalies, such as nevus flammeus
or nevus sebaceus [5], one might expect that nevus psiloliparus
should likewise occur rather often as an isolated anomaly. Most
likely, such cases have so far been overlooked or misdiagnosed as
sebaceous nevus or aplasia cutis congenita.
In the present case, the CNS could not be examined by imaging
techniques, but such extracutaneous involvement is highly unlikely
for the following reasons. Firstly, the skin lesions were of
limited size when compared to the extent of involvement as noted in
children with encephalocraniocutaneous lipomatosis [2-4, 6].
Secondly, epibulbar choristomas or lipodermoids, as usually found
in children with encephalocraniocutaneous lipomatosis [1-4, 6, 7],
were absent. Thirdly, the children had no clinical sign of
neurological involvement and showed a quite uncomplicated
development during a follow-up period of two years in either case,
respectively. Admittedly, however, the presence of small
intracerebral lipomas cannot be excluded with certainty because
they may exist even in the absence of any neurological symptoms
[8].
In conclusion
These cases suggest that nevus psiloliparus may occur without any
associated abnormality. When clinicians and
dermatohistopathologists have become familiar with this new skin
disorder, they will certainly recognize it in a nonsyndromic form
more often than in association with encephalocraniocutaneous
lipomatosis.
References
1 Happle , Küster Nevus psiloliparus: a distinct fatty
tissue nevus Dermatology 197 1998 6-10
2 Happle , Steijlen Enzephalokraniokutane Lipomatose: ein
nichterblicher Mosaikphänotyp Hautarzt 44 1993 19-22
3 Grimalt , Ermacora , Mistura , Russo , Tadini , Triulzi
, Cavicchini , Rondanini , Caputo Encephalocraniocutaneous
lipomatosis: case report and review of the literature Pediatr
Dermatol 10 1993 164-168
4 Ciatti , Del Monaco , Hyde , Bernstein
Encephalocraniocutaneous lipomatosis: a rare neurocutaneous
syndrome J Am Acad Dermatol 38 1998 102-104
5 Boente , Pizzi de Parra , Larralde de Luna , Bibas
Bonet , Santos Muñoz , Parra , Gramajo , Moreno , Asial
Phacomatosis pigmentokeratotica: another epidermal nevus syndrome
and a distinct type of twin spotting Eur J Dermatol 10 2000
190-194
6 Gawel , Schwartz , Józwiak Encephalocraniocutaneous
lipomatosis J Cutan Med Surg 7 2003 61-65
7 Kodsi , Bloom , Egbert , Holland , Cameron Ocular and
systemic manifestations of encephalocraniocutaneous lipomatosis Am
J Ophthalmol 118 1994 77-82
8 Torrelo , Boente , Nieto , Asial , Colmenero , Winik ,
Zambrano , Happle Nevus psiloliparus and aplasia cutis: a further
possibile example of didymosis Pediatr Dermatol 21 2004 in
press
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