Correspondence 333 © 2006 The Authors Journal Compilation © 2006 International Society of Neuropathology • Brain Pathology A 4-YEAR-OLD GIRL WITH MASS IN THE FRONTOTEMPORAL BONE Contributed by: Shanop Shuangshoti 1 ; Sukruthai Mujananon 1 ; Krishnapundha Bunyaratavej 2 ; Mookda Chaipipat 1 ; Surachai Khaoroptham 2 1 Department of Pathology and 2 Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. CLINICAL HISTORY A 4-month-old female infant presented with a growing extracranial mass at the left frontotemporal region. Covered with intact skin, the lesion measured 3.5 × 3 × 3 cm; it was well-defined, bony hard in consistency, and fixed to the under- lying skull. There were no other abnormal symptoms, and routine laboratory tests were within normal limits. The mass appeared sclerotic on skull film. Comput- erized tomography scan of the brain (Figure 1A) showed a homogeneously enhancing expansile bone tumor. The lesion caused widening of the lower part of the left coronal suture, just above the orbital roof. The patient underwent left frontotemporal craniotomy, and the mass was found to involve the frontal and tem- poral bones, around the inferior limb of the coronal suture, adherent to the under- lying dura. The orbital roof and apex were also affected. The lesion was totally resected. The immediate postoperative course was uneventful. On gross inspection of the fresh speci- men, the mass was hard and showed gray tan cut surfaces (Figure 1B). MICROSCOPIC FINDINGS Intraoperative smears and imprints disclosed bimodal population of large melanin-containing epithelial cells and smaller neuroblast-like cells (Figure 2). The former possessed abundant pale eosino- philic cytoplasm, whereas the latter appeared as round naked nuclei with finely dispersed chromatin pattern. Thick clus- ters of fibrovascular tissue were also evi- dent. An intraoperative diagnosis was rendered. Permanent sections subsequently confirmed the diagnosis by demonstrating lobules of monotonous small round cells (Figure 3A), and pigmented epithelial cells with glandular formation (Figure 3B). Mitotic figures were rarely observed, 0–1/ 10 high-power field (HPF). Immunohis- tochemically, the small round tumor cells expressed synaptophysin (Figure 4A), while the pigmented epithelial cells were reactive for cytokeratin (Figure 4B) and HMB-45 (Figure 4C). CORRESPONDENCE: Reader Submitted Case Reports Edited by Dr Ronald L. Hamilton Figure 1. A B Figure 2. Figure 3. A B Figure 4. A B C