Neurofibroma vs. Ping-pong Fracture
Left picture: The clinical findings point to an epidermoid cyst; however, neither the operative finding in the picture at the bottom, nor the histological examination confirmed this clinical diagnosis, but revealed a plexiforme neurofibroma. The latter diagnosis explains the pain on palpation because there are no visible signs of an infected epidermoid cyst, which is leading to pain, too. The case report illustrates that in excised tumors or tumor-like masses of the skull a histological work-up is always necessary. Right picture: Here, a depressed skull fracture is present which is called a ping-pong or a celluoid ball fracture, and which is typical for newborns and for infancy; the peripheral ridge is caused by a subperiosteal hematoma which also partially hides the dent. The picture at the bottom shows a CT with the ping-pong fracture.
In both patients a swelling is visible above the auricle in a high-parietal position. Left picture: This pathology on the right side of the head concerns a 2.5-year-old toddler; the mass is covered by normal skin, flat, and painful on palpation. Right picture: In this pathology on the left side of the head the swelling is flat, but reveals at the periphery a wall, and, on looking closely and on palpation, has a dent in the center.