Cutaneous plasmacytoma adjacent to Bowenoid actinic keratosis on the scalp: Is there a link?

INTRODUCTION: Cutaneous extramedullary plasmacytoma without bone marrow involvement is very rare. We present a plasmacytoma on the scalp with an adjacent Bowenoid disease. PRESENTATION: An 86 year old man presented to our unit with an ulcerated lump on the vertex of the scalp. Excisional biopsy showed plasmacytoma with adjacent Bowenoid actinic keratosis. Blood tests did not show any systemic multiple myeloma. However, skeletal survey showed possible osteolytic lesions in some areas. Sixteen months afterwards, the patient remains well on follow up. DISCUSSION: As far as we know, this is the first reported case of a cutaneous plasma cell tumour next to an area of Bowenoid actinic keratosis. Relevant literature is investigated here for possible correlation. CONCLUSION: Within the limitations of this study, solitary primary cutaneous plasmacytoma can be treated surgically with a favourable outcome. A hypothesis of correlation between Bowenoid actinic keratosis and plasmacytoma is investigated here. Further research is needed to confirm this finding.