mastocytosis (CM) requires the demonstration of typical clinical findings and histological proof of abnormal mast cell
infiltration of the dermis
. In case
s of isolated CM, there is no evidence of system
ic involvement using such parameter
s as elevated levels of total serum
typase or organ
omegaly. Recently, criteria for the diagnosis
of CM have been further refined and three major variants of CM are now recognized: Urticaria pigment
osa (UP)/maculopapular cutaneous
mastocytosis (MPCM), diffuse cutaneous
mastocytosis, and solitary mastocytoma of skin.
mastocytosis is the most frequent form of CM. In children the lesion
s of UP tend to be larger and papular. Histopathology
typically reveals aggregates of spindle-shaped mast cell
s filling the papillary dermis
and extending as sheets and aggregates into the reticular dermis
, often in perivascular and periadnexal positions. A subvariant, usually occurring in young children, presents as non-pigmented, plaque
s. In adults the lesion
s are disseminated
and tend to be red or brown and macula
r or maculopapular.
mastocytosis occurs almost exclusively in childhood. The skin is diffuse
ly thickened and may have an orange peel appearance. There are no individual lesion
s. Atypical cell
s are not present, which can help distinguish this disease from a mast cell
sarcoma (9740/3) occurring in the skin.
Mastocytoma of skin occurs as a single lesion
, almost exclusively in infants. These mast cell
infiltrates may extend into the subcutaneous tissue
Extracutaneous mastocytomas has been reported in the lung
. This isolated mast cell tumor
has a non-destructive growth pattern.