Background: Metastasis from one tumor into another is known as tumor-to-tumor metastasis. We report a case of a contiguous occurrence of meningioma and brain cancer metastasis.
Patient: A 91-year-old woman presented with a sudden onset of weakness in her right limbs and gait disturbance. Fourteen years previously, she had a tumor that was suspected to be a meningioma in the left frontal convexity with no change for several years. One year earlier to presentation she was diagnosed with lung carcinoma in the left lower lobe.
Results: Magnetic resonance images revealed enlargement of the tumor with perifocal edema. Histologic examination showed a meningioma with contiguous metastatic poorly differentiated adenocarcinoma, as well as a clearly defined border between the two components. The clinical origin of the metastasis was presumed to be from the left lower lobe of the lung.
Conclusion: Although our case does not strictly fulfill the definition of tumor-to-tumor metastasis, we suggest a contiguous occurrence develops by the same mechanism and may be a subtype of this process. Although previous reports suggested the loss of epithelial cadherin (E-cadherin) expression in the recipient tumor as the cause of contiguous metastasis, E-cadherin expression was positive in our case and did not seem to be involved in the localization of the metastasis.
Georg Thieme Verlag KG Stuttgart · New York.