Palpable mass on the skull.
The first two patients with the vascularized mass had a Langerhans cell histiocytosis of the skull. The 2 patients with the non vascularized lesion had an epidermoid cyst.
Langerhans cell histiocytosis (LCH) is a rare disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes. Clinically, its manifestations range from isolated bone lesions like the skull to multisystem disease. LCH is part of a group of clinical syndromes called histiocytoses, which are characterized by an abnormal proliferation of histiocytes.
Dermoids and epidermoids are slow-growing benign cysts that typically occur in the scalp and the skull of infants and young children. These result from a part of the scalp, either the epidermis (top layer) or dermis (bottom layer) being misplaced underneath the scalp. This causes the formation of a small cyst filled with normal skin components.