Primary intraosseous carcinoma

Last revised by Joachim Feger on 29 Dec 2021

Primary intraosseous carcinomas NOS (PIOC) are malignant epithelial odontogenic neoplasms of the jawbones with no clear benign analog.

Primary intraosseous carcinomas are rare tumors 1-4. They occur in a wide age range with the mean in the sixth decade of life. Men are more frequently affected 4.

Primary intraosseous carcinomas are a diagnosis of exclusion and are only diagnosed after other carcinomas in particular primary metastatic carcinomas or extension of oropharyngeal carcinomas have been excluded 1,2.

Clinical symptoms are nonspecific. They might be found incidentally, present with swelling pain or metastatic disease 1-3.

Primary intraosseous carcinomas are malignant epithelial tumors that arise from epithelial remnants of the dental lamina, the odontogenic epithelium from a cyst or other epithelial lesions 2,3.

Primary intraosseous carcinomas are most often found in the posterior body and ramus of the mandible. Less commonly they are found in the anterior part of the maxilla 2.

Histologically primary intraosseous carcinomas have similar features as squamous cell carcinoma 1-3:

  • small sheets, strands or nests of atypical squamous cells
  • cellular pleomorphism
  • nuclear hyperchromatism
  • increased mitotic activity
  • no features of ameloblastoma
  • rarely significant keratinization

Immunohistochemistry helps differentiate primary interosseous carcinomas from carcinomas of other sites 2. CK19 positivity suggests origin from odontogenic epithelium 5.

The orthopantomogram usually shows a radiolucent lesion. Larger lesions might show cortical perforation and destruction 2.

The radiological report should include a description of the following features:

  • type location and size of the lesion
  • unilocular or multilocular appearance
  • relation to the adjacent structures and teeth
  • unerupted tooth or tooth displacement

Management includes radical resection with neck dissection and possibly adjuvant radio and/or chemotherapy 1-5. Lymph node metastases are common whereas distant metastases are uncommon. Still, the prognosis is poor with a five-year survival rate of less than 40% 5,6 and a slightly better prognosis in cases originating from cysts 2,3.

The primary intraosseous carcinoma has been first described by D.Loos in 1913 as central epidermoid carcinoma 7.

The differential diagnosis of primary intraosseous carcinomas include the following:

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.