title: Calvarium and dura mater as delayed sites of distant metastasis from papillary thyroid carcinoma.
abstract: BACKGROUND
  Skull calvarium and dura mater are rare sites of distant metastasis, and mostly have been reported in lung, breast, and prostate malignancies. However, the calvarial and dural metastases from papillary thyroid cancer (PTC) are rare entities and pose diagnostic and therapeutic challenges. To date, only seven cases of calvarial metastasis with intracranial extension from PTC have been reported in literature. However, true dural metastasis from PTC has not yet been reported.
  
  
  METHODS
  A 65-year-old Saudi woman presented with 6 months history of painful posterior scalp lump, 7 years after initial diagnosis of PTC. Computed tomography and magnetic resonance imaging showed occipitoparietal calvarial lesion with massive intracranial extension. Another para-sagittal lesion was found at the top of corpus callosum mimicking a meningioma. Histopathology of para-sagittal lesion and the biopsy of calvarial mass confirmed the diagnosis of metastatic PTC. After surgical resection, residual tumors were treated with postoperative intensity-modulated radiation therapy. At 13 months of follow-up, patient was alive and without any signs of recurrence.
  
  
  CONCLUSIONS
  Calvarial and dural metastases from PTC are extremely rare clinical entities. Surgical resection followed by postoperative radiotherapy is the treatment of choice. However, for such cases, multidisciplinary approach can prolong the treatment outcome and survival.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Khalid Hussain
authors.initials: KH
authors.lastname: Al-Qahtani
authors.affiliation: Radiation Oncology Department, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Mutahir A
authors.initials: MA
authors.lastname: Tunio
authors.affiliation: Radiation Oncology Department, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Mushabbab
authors.initials: M
authors.lastname: Al Asiri
authors.affiliation: Histopathology Department, Comprehensive Cancer Center, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Hanadi
authors.initials: H
authors.lastname: Fatani
authors.affiliation: Radiation Oncology Department, National Cancer Institute, Cairo, Egypt.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Bayoumi
keywords: calvarial metastasis; intracranial extension; papillary thyroid carcinoma; true dural metastasis