Solitary plasmacytoma of the skull: Two case reports

Abstract

Solitary plasmacytoma of the skull is rare and few cases have been reported in the English literature. Plasmacytoma of the skull has a wide spectrum of pathology, including a quite benign, solitary plasmacytoma (SPC), and an extremely malignant, multiple myeloma (MM) at the two ends of the spectrum. The prognosis for solitary plasmacytoma of the skull appears to be good when it can be diagnosed on strict criteria. The clinical features of solitary plasmacytoma of the skull are complex and not easily identified, resulting in a high misdiagnosis rate. A comprehensive examination and analysis which includes radiological examination, immunoglobulin, biochemistry, test for Bence Jones protein in the urine and bone marrow is needed for correct diagnosis. If the skull lesion is isolated, with accompanying marked swelling in the area and tenderness, plasmacytoma must be considered as a possibility for the cause of solitary skull masses. Two cases of solitary plasmacytoma of the skull lesions were retrospectively reviewed, in which a comprehensive examination was used in order to predict the clinical course of solitary plasmacytoma of the skull. The patients received postoperative radiation and/or chemotherapy. Survival following surgery was longer than 2 years for patient 1, and patient 2 is alive at the 18-month follow-up.

Solitary plasmocytoma of the skull

“…True solitary plasmocytomas of the skull vault are very rare. Diagnostic criteria of a solitary plasmocytoma include a solitary lesion, histopathological confirmation, negative bone marrow examination or negative PET CT, negative urine test for Bence Jones protein, absence of anaemia, abnormal kidney function and serum immunoglobulins 1 3 6 7. Our case meets all the criteria for the diagnosis of solitary plasmocytoma of the skull.…”

“…The diagnosis of plasmocytoma also needs to be differentiated from eosinophilic granuloma, osteosarcoma, metastatic carcinoma and meningioma 1 6. Eosinophilic granuloma is mainly seen in children and young individuals and they are mostly small single lesions with well-defined borders.…”

“…Pathological proliferation of the plasma cells produces a variety of disorders from benign solitary plasmocytomas to malignant multiple myeloma 1 2. Plasma cell tumours include solitary plasmocytoma, multiple plasmocytoma and multiple myeloma.…”

“…Solitary plasmocytoma of the bone including skull is defined as a radiologically solitary bone lesion, neoplastic plasma cells in the biopsy specimen, fewer than 5% plasma cells in the bone marrow, less than 2 g/dL monoclonal protein in the serum when present and negative urine test for Bence Jones protein 3. True plasmocytoma of the skull without findings of multiple myeloma is very rare 1 4 5. It is very important to make the correct diagnosis of solitary plasmocytoma and differentiate it from the multiple myeloma since their treatment and prognosis are totally different.…”

An unusual initial presentation of a lung carcinoma with multiple extensive bone metastasis – a diagnostic dilemma

“…Interestingly, there were two case reports found in literature describing a similar presentation with large bony scalp lumps which on further testing, have found to be deposits from a primary hepatocellular carcinoma in one patient 6 , and a plasmacytoma in the other. 7 The deep FNAC from large posterior scalp lump revealed a metastatic deposit of squamous cell origin. Squamous cell carcinoma of the lung (SqCC) represents 30% of all non-small cell lung carcinomas (NSCLC).…”