Multiple myeloma in a patient with neurofibromatosis
Authors: Nurullah Zengin, Müzeyyen Gönül, Ülker Gül, Berna Öksüzoğlu, Arzu Kiliç, Seray Külcü Çakmak, Ünal Sakinci
Journal: American Journal of Hematology (2007)

Multiple myeloma in a patient with neurofibromatosisTo the Editor: Neurofibromatosis Type 1 (NF1) is one of the most common autosomal dominant disorders characterized by multiple brown skin macules (cafe au lait spots), intertriginous freckling, iris hamartoma (lisch nodules), and multiple skin neurofibromas [1].NF1 is associated with a number of neoplasms, including pheochromocytoma, Wilms tumor, neuroblastoma, meningioma, glioma, fibrosarcoma of bone, leukemia, Hodgkin's disease, and lymphoma [2].However, multiple myeloma is rare in patients with NF1.We describe a case of multiple myeloma developing in a patient with NF1; the third case in the literature.A 63-year-old man attended our clinic with multiple, disseminated cafe au lait spots, multiple skin neurofibromas, and a 2-cm sized, painful, subcutaneous tumor on the sternum.NF1 was diagnosed 40 years ago.There was no family history for NF1.Axillary and inguinal freckling and lisch nodules were detected on dermatologic and ophtalmologic examination, respectively.Routine laboratory tests were normal except mild anemia (11 g/dL normal: 12-16 mg/dL) and increased sedimentation rate (87 mm/hr).Abdominal ultrasonography did not show pathologic findings.Thorax computed tomographic scan disclosed destructive lesions and focalincreased activity in the vertebrate's sternum and 5th, 7th, and 8th costas.The lesions in sternum and costa were biopsied, and their histopathological examination revealed the diagnosis of plasmocytoma.Serum immunoglobulin (Ig) G level was normal but IgM (0.2 g/L, normal range: 0.4-2.3g/L) and IgA (0.2 g/L, normal range: 0.7-4 g/L) levels were decreased.Bence Jones protein was positive in urine test.Monoclonal l light chain was detected in urine immunofixation electrophoresis.The diagnosis of multiple myeloma was confirmed with the bone-marrow smear showing atypical plasma cells.NF1 is frequently complicated by neoplasms of neural crest origin.Rarely, malign diseases of other than neural crest origin occurs, including malign lymhoma, Hodgkin's disease leukemia, malign endocrin tumor of the pancreas, and adenocarcinoma of papilla of Vater [2].Multiple myeloma is a neoplastic clonal disease characterized morphologically by plasma cell infiltration of the medullary space and involvement of extraosseous tissues [3].Two cases of multiple myeloma associated with NF1 were reported in the literature.Relationship between NF1 and multiple myeloma is unknown.The NF1 gene, located on region 17q11.2,produces a GTPase-activating protein, which provides tumor suppressor function [1,4].Either a duplication of the 17q containing the NF1 locus or a loss of 17p containing p53 may provide the evaluation of tumor [4].Also normal or mutated NF1 gene may affect genes in or near locus and may contribute to tumorigenesis [4].The cytogenetic analysis for multiple myeloma showed complex chromosome abnormality of i (1q+), 8q+, 13q+, i (17q), i (18q), and +M.The high incidence of p53 (17p13.1)deletions was detected in central nervous system myeloma by Chang et al. [5].Patients with p53 deletions had significantly shorter progression-free and overall survival than patients without a p53 deletion in multiple myeloma.We think that NF1 might have developed by genetic mutation in our patient because our patient did not have any relatives with NF1, and same genetic mutagen may also affect a possible gene, which may be located in 17th chromosome, for multiple myeloma.