An Unusual Bump on the Head: Intracranial and Extracranial Cytokeratin-Positive Interstitial Reticular Cell Tumor

Necropsy‐confirmed case of cytokeratin‐positive interstitial reticulum cell tumor in the skull bone

“…The prognosis of CPIRCT is unclear, although local recurrence and/or metastatic spread have been reported. 4 The present case did not exhibit aggressive pathological features, such as strong cell atypia, necrosis, and high Ki67 index; however, the tumor extensively invaded and destroyed the skull bone. We must carefully consider the aggressive features of CPIRCT.…”

“…3 Electron micrographs of CPIRCTs have revealed desmosome-like cell adhesion, supporting the fact that the tumor was derived from reticular tissue. 4 Herein, we report the first case of CPIRCT in the skull bone, with noncaseating granuloma in intra-abdominal lymph nodes.…”