10601 Background: Brachial plexopathy is a well-recognized complication of breast cancer, most attributed to late effects of radiation. However, direct involvement of brachial plexus by recurrent breast cancer occurs. Misdiagnoses may lead to inappropriate attribution of the plexopathy to radiation, and therefore inappropriate therapy. Methods: We report fourteen cases of brachial plexopathy secondary to breast cancer diagnosed at the Mayo Clinic-Rochester from 2003 to 2005. Results: Thirteen of fourteen primary tumors and 12/14 recurrences were ER/PR positive. Only 1/14 patient had Her 2 neu overexpression. The median time from the original breast cancer diagnosis to first brachial plexus symptom was 14 years. The median time from the development of symptoms to diagnosis was 8 months with the range being 1 month to 8 years. MRI revealed a distinct mass in 3/13 patients, plexus thickening in 5/13, and was normal in 5/13. Only 5/13 original MRI interpretations suggested tumor. In four patients that the 1.5 T MRI was either interpreted as normal or unlikely cancer the 3 Tesla MRI revealed abnormal uptake suggestive of malignancy. PET scan suggested malignancy in 3/6 patients. Two of these cases had other metastatic disease. In the other three cases that PET scans were done the uptake was mild, suggesting inflammation rather than malignancy. Reinterpretations of the PET scan and MRI in combination by an experienced musculoskeletal radiologist was highly suggestive of malignancy in all cases. Definitive diagnosis was eventually obtained by biopsy of the brachial plexus (7/14) or another site of metastasis in (4/14). Conclusions: The often slowly progressive nature of hormonally driven breast cancer can mimic radiation induced brachial plexopathy. In the cases reviewed, PET was not reliable in differentiating inflammation from tumor. MRI findings are nonspecific and higher resolution 3T MRI may be needed to detect an abnormality. Interpretation of MRI and PET together is useful. Patients with a history of breast cancer, and brachial plexus symptoms should be carefully evaluated with consideration for recurrent disease as a cause. Biopsy of the brachial plexus can be done safely and has an important role in diagnosis. No significant financial relationships to disclose.
Recurrent Breast Cancer Diagnosis Delayed by COVID-19 Pandemic
