Granular Cell Tumor of the Breast Synchronous to Retroperitoneal Castleman’s Disease: Case Report and Literature Review

Abstract

Introduction: The Granular cell tumor is a rare benign neoplasia that can occur in any part of the body. In the breast, it represents 5-6% of all granular cell tumors. It is usually a nodular tumor that can mimic an invasive carcinoma on breast imaging. Histologically, it is characterized by a proliferation of polygonal cells with granular appearance, which group themselves in nests, cords or sheets and present a strong immune-histochemical marker for S-100 protein. The Castleman’s disease is a rare benign lymphoproliferative illness of unknown etiology characterized by proliferation of the lymphoid tissue in any lymphatic chains. Clinically, this disease is divided into unicentric and multicentric; the cure of the Unicentric Castleman’s disease is possible through surgical excision, while the multicentric disease has a poorer prognosis in the long run. Case report: We report a case of a patient with a nodule in the breast suggestive of carcinoma who had the diagnosis of a granular cell tumor and, in staging tests, showed a mass in the retroperitoneum which, after surgical resection, was diagnosed as Castleman’s disease. Conclusion: We must have the granular cell tumor as a differential diagnosis of breast malignant tumors because of their similarity on clinical and image exams. The Castleman’s disease must be in differential diagnosis of retroperitoneal masses.