Paraneoplastische dermatosen als initiële presentatie van multipel myeloom

Paraneoplastic dermatoses as initial presentation of multiple myeloma A 70-year-old woman presents with painful annular, papular to edematous erythematous lesions on the chin, neck, chest, and upper back. A skin biopsy shows a dense neutrophilic infiltrate in the dermis, consistent with Sweet's syndrome. In the following weeks, the clinical picture evolves into erythema gyratum repens, a rare paraneoplastic entity. Biochemical analysis reveals inflammatory markers with elevated sedimentation rate and the presence of a monoclonal spike. Further hematological examination leads to the diagnosis of multiple myeloma with osteolytic bone lesions, preserved renal function and absence of hypercalcemia. Treatment with daratumumab, lenalidomide and dexamethasone is initiated. Two months after starting treatment, the patient presents with rapidly growing nodules on the scalp. A biopsy confirms the presence of plasmocytomas, an extramedullar manifestation of multiple myeloma, for which radiotherapy is initiated. This case illustrates how paraneoplastic phenomena, specifically Sweet’s syndrome and erythema gyratum repens, can lead to the diagnosis of an internal malignancy. Paraneoplastic dermatoses are rare, yet timely recognition is essential for detecting an underlying malignancy. This article summarizes the available literature on cutaneous paraneoplastic phenomena in multiple myeloma.