Benign Cephalic Histiocytosis
Benign cephalic histiocytosis (BCH) falls into the group of non–Langerhans cell histiocytosis (non-LCH), which is characterized by a benign course and tendency toward spontaneous remission. Apart from BCH, the main types of non-LCH include juvenile xanthogranuloma, generalized eruptive histiocytoma, and xanthoma disseminatum. Lesions often are confused with plane warts.
Figure 2. Skin section showing the upper and mid dermis infiltrated with slightly pleomorphic epithelioid histiocytic cells with clear cytoplasm and vesicular nuclei. Few accompanying lymphocytes and eosinophils were visible (H&E, original magnifications ×200 and ×400). |
A close histologic relationship and presence of overlapping symptoms observed among BCH, GEH, and juvenile xanthogranuloma indicate that these entities fall into a spectrum of the same disorder. However, the presence of a uniform infiltrate of large foamy histiocytes readily distinguishes xanthomas from BCH.4 In some unusual clinical presentations of CM or in cases of the nodular form of the condition, there is a need to distinguish between non-LCH and CM, as in our patient. Darier sign, consisting of urtication and erythema appearing after mechanical irritation of the skin lesion, is pathognomonic for CM. Nevertheless, Darier sign is not sufficient to confirm CM when it is not pronounced. Therefore, histologic examination with the use of immunostaining plays a key role in the differential diagnosis of these disorders in children.15 Treatment of BCH is not recommended because of spontaneous remission of the disease.1-5
Benign cephalic histiocytosis is a rare clinical form of non-LCH. No systemic or mucosal involvement has been described. Lesions often are confused with plane warts, but a biopsy is definitive. Therapy is not effective but fortunately none is necessary.
