Multifocal Rosai Dorfman disease and simultaneous endometrioid ovarian cancer: a case report

BACKGROUND: Rosai Dorfman disease is a rare histiocytosis, which is characterized by accumulation of histiocytes in lymph nodes, but also in extranodal locations. Histologically, one of the key features of Rosai Dorfman disease is emperipolesis. Treatment options involve surgical resection, radiation, chemotherapy, corticosteroids, and immunotherapy. Rosai Dorfman disease treatment depends on disease location and symptomatology. Patients with mild nodal or cutaneous involvement usually have a self-limited course and require observation only. The exact pathogenesis of Rosai Dorfman disease is still being evaluated, but mutations of the Kirsten rat sarcoma virus gene are found in up to a third of the patients and are linked to multifocal disease. Recent publications and case reports have shown that treatment with the mitogen-activated protein kinase kinase inhibitor Cobimetinib is a possible option in Rosai Dorfman disease patients with Kirsten rat sarcoma virus gene mutation. CASE PRESENTATION: In this case report, we are presenting and discussing the case of a 47-year-old Caucasian female patient with multifocal Rosai Dorfman disease and simultaneous endometrioid ovarian cancer, who underwent median laparotomy for tumor debulking of the endometrioid ovarian cancer and in which a Kirsten rat sarcoma virus gene mutation was detected and a treatment with Cobimetinib was initiated, leading to sustained remission. CONCLUSION: While there are case reports on patients with Rosai Dorfman disease with a simultaneous cancer diagnosis, and while some authors describe Rosai Dorfman disease as a possible neoplastic process itself, it remains unclear if there is a causal association between Rosai Dorfman disease and cancer.