A calvarial osteolytic lesion of probable vascular origin in a Maya juvenile from the Classic Period ( 250-900 CE).

Objective: This case study evaluates a focal osteolytic lesion in the right sulcus sinus transversi of an isolated os occipitale.

Materials: The os occipitale is from a juvenile from the Cueva de Sangre at the Classic Period (250-900 CE) site of Dos Pilas, Guatemala METHODS: The lesion was examined macroscopically, microscopically, and radiographically.

Results: The oval lesion has a well-circumscribed margin, endocranial origin, and involves cortical destruction of the inner and outer tables. Subperiosteal bone reaction around the lesion is present on the ectocranial surface. Skeletal evidence of increased vascularity, diploë expansion, and perimortem fracture near the lesion are not observed.

Conclusions: The lesion appears to reflect a response to the presence of an expansile process that has caused pressure erosion. The anatomical location of the lesion and the endocranial origin suggest a probable vascular anomaly, such as a vascular malformation.

Significance: This case study represents one of the few bioarchaeological evaluations of probable vascular anomaly in a juvenile. As such, it expands our knowledge about vascular anomalies in the past and provides a comparative and core reference for guiding future paleopathological investigations on cranial osteolytic lesions.

Limitations: The skeletal assemblage is commingled and fragmentary preventing the assessment of the distribution of lesions across the skeleton.

Suggestions For Future Research: Further scrutiny of bioarchaeological collections is needed to better understand the distribution of vascular anomalies in the past.