Pleural Schwannoma Suspected as Metastasis of Breast Cancer

Schwannomas Mimicking Leptomeningeal Spread in the Setting of Breast Cancer: A Case Report

BACKGROUND

Breast cancer is currently the most diagnosed cancer globally. For patients who complete breast cancer treatment, developing a survivorship plan is important, including serial history, physical examinations, and annual mammograms to look for recurrence and metastasis.

CASE REPORT

This is a case report of a 76-year-old female with a history of recurrent breast cancer who presented with lower-back pain and found to have MRI findings initially concerning for intradural extramedullary metastatic disease. Biopsy was later found to be consistent with benign spinal schwannomas.

CONCLUSION

We present a unique case of spinal masses in the setting of breast cancer initially concerning for leptomeningeal spread, later found to have benign schwannomas that mimicked leptomeningeal spread on imaging. To our knowledge, this is the first reported case of schwannomas mimicking leptomeningeal spread in a patient with a history of recurrent breast cancer. After metastasis is excluded, schwannomas should be considered in the differential of benign spinal lesions.

Nivolumab induced pulmonary sarcoid-like granulomas with a concurrent pleural schwannoma: A pathologic-radiologic correlation of a rare condition mimicking metastatic melanoma

Nivolumab is an anti-PD-1 antibody. The mechanism of action of nivolumab is inhibition of binding between PD-1 and PD-1 ligand. This causes activation of antigen-specific T cells that were previously unresponsive to cancer cells. This unique mechanism of action attributes the widespread use of nivolumab for the treatment of a variety of neoplastic conditions. On the other hand, this mode of action is associated with adverse effects as well. Schwannoma, also called neurilemmoma, is a benign peripheral nerve sheath tumor. Pleural schwannomas are very rare and very few cases have been reported in the medical English literature so far. Herein, we report a very rare case of concurrent presence of Nivolumab induced pulmonary sarcoid-like granulomas along with primary benign pleural schwannoma in a 49-year-old male. He was diagnosed with malignant melanoma of the right upper arm for which he underwent surgery and was receiving adjuvant chemotherapy. He developed pneumonitis during chemotherapy, and on imaging multiple reticular and nodular interstitial infiltrates were seen along with an incidental pleural mass with a high suspicion for metastasis. Wedge biopsy of the interstitial infiltrates was done and they were found to be pulmonary granulomas related to the nivolumab therapy he was receiving. The patient underwent excision of the pleural mass which showed histopathological and immunohistochemical features of schwannoma. The two conditions are unrelated and rarely encountered simultaneously. The radiologic and pathologic correlation along with differential diagnosis of these conditions are discussed.