Imaging of Adamantinoma: Radiologic Features Related to Metastatic Risk Prediction

Purpose or Learning Objective: Adamantinoma is a very rare primary malignant tumor of bone, accounting for ~ 0.1 to 0.5% of all primary bone tumors. Although considered a low-grade malignancy tumor, in a smaller number of cases it may show aggressive behavior with distant metastases and reduced overall survival. A histologic grading for this rare tumor is still lacking, rendering its metastatic risk stratification very difficult. Our study aimed to assess the imaging features of adamantinoma and correlate them with the onset of metastatic disease.

Methods or Background: We retrospectively reviewed all clinical records and baseline radiologic studies (conventional radiography, magnetic resonance imaging, and computed tomography) of patients diagnosed with adamantinoma at our single sarcoma center from 2006 to 2022. Tumor dimensions, radiologic pattern, Lodwick grading, periosteal reaction, multifocality, soft tissue extraskeletal component, peritumoral edema, peritumoral enhancement, and vascular invasion were analyzed and recorded. We correlated these radiologic features with the presence of metastatic disease.

Results or Findings: Twenty-two patients were included in the analysis (7 males and 15 females; mean age: 28.8 years, range: 7–58 years). Six of 22 patients (27.3%) developed distant metastases: two patients (9%) presented with metastatic disease at diagnosis, and four patients (18.2%) developed metastases in the subsequent follow-up controls. Several radiologic features were significantly correlated with the development of distant metastases during follow-up controls using the Fisher exact test: (1) presence of an extraskeletal component (P = 0.0004), (2) vascular invasion (P = 0.0002), (3) diffuse peritumoral edema (P = 0.0004), and (4) peritumoral enhancement (P = 0.001). All the other features analyzed were not significantly associated with the onset of distant metastases, including the maximum diameter (P = 0.6653).

Conclusion: An accurate evaluation of baseline imaging studies in patients affected by adamantinoma may help significantly in prognosis prediction by selecting patients at high metastatic risk. For these patients, strict follow-up controls and personalized treatments should be suggested after multidisciplinary discussions in sarcoma centers.

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Artikel online veröffentlicht:
02. Juni 2025