Journal of Neuro-Ophthalmology, December 2000, Volume 20, Issue 4

Sixth Nerve Palsy as a Presenting Sign of Intracranial Palsmacytoma and Multiple Myeloma

Multiple myeloma and plasmacytoma are rare causes of mass lesions at the skull base and cavernous sinus. Sixth nerve palsy, in isolation or in combination with other cranial neuropathies, may occur rarely as the initial presenting feature of multiple myeloma. We report the neuro-ophthalmologic, radiologic, and pathologic findings for two patients who developed sixth nerve palsies as an initial manifestation of intracranial plasmacytoma and multiple myeloma. One patient presented with an isolated sixth nerve palsy in the setting of multiple vasculopathic risk factors. Treatable skull base lesions, including plasmacytoma and multiple myeloma, must be considered in patients with sixth nerve palsies, especially among those who demonstrate a progressive course or multiple cranial neuropathies.

Journal of Neuro- Ophthalmology 20( 4): 242- 245, 2000. © 2000 Lippincott Williams & Wilkins, Inc., Philadelphia Sixth Nerve Palsy as a Presenting Sign of Intracranial Plasmacytoma and Multiple Myeloma Tammy Z. Movsas, MD, Laura J. Balcer, MD, MSCE, Eric R. Eggenberger, DO, Jay L. Hess, MD, PhD, and Steven L. Galetta, MD Multiple myeloma and plasmacytoma are rare causes of mass lesions at the skull base and cavernous sinus. Sixth nerve palsy, in isolation or in combination with other cranial neuropathies, may occur rarely as the initial presenting feature of multiple myeloma. We report the neuro- ophthalmologic, radiologic, and pathologic findings for two patients who developed sixth nerve palsies as an initial manifestation of intracranial plasmacytoma and multiple myeloma. One patient presented with an isolated sixth nerve palsy in the setting of multiple vasculopathic risk factors. Treatable skull base lesions, including plasmacytoma and multiple myeloma, must be considered in patients with sixth nerve palsies, especially among those who demonstrate a progressive course or multiple cranial neuropathies. Key Words: Diplopia- Hypoglossal nerve- Multiple my­eloma- MR imaging- Plasmacytoma- Sixth nerve. Sixth nerve palsy, in isolation or combination with other cranial neuropathies, has rarely been described as the initial presenting feature of intracranial plasmacy­toma or multiple myeloma ( 1,2). In fact, less than 4% of all cases of cavernous sinus syndrome have occurred in the setting of multiple myeloma ( 3). We describe two patients who developed binocular horizontal diplopia as the initial manifestation of intracranial multiple myeloma and plasmacytoma. Patient characteristics are summa­rized in Table 1. CASE REPORTS Casel A 78- year- old woman with a history of diabetes mel-litus, hypertension, coronary artery disease, hypercholes­terolemia, and atrial fibrillation presented with binocular horizontal diplopia that was worse in right gaze. The diplopia had progressed over 1 month. A right frontal Manuscript received July 21, 2000; accepted September 12, 2000. From the Departments of Neurology and Ophthalmology ( TZM, LJB, SLG), and Pathology and Laboratory Medicine ( JLH), University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; and the Department of Neurology ( ERE), Michigan State University, East Lansing, Michigan. Address correspondence and reprint requests to Laura J. Balcer, MD, MSCE, Department of Neurology, 3 E. Gates, 3400 Spruce Street, Philadelphia, PA 19104. headache was noted 1 week after the onset of diplopia. There was no history of amaurosis fugax, jaw claudica­tion, scalp tenderness, or myalgias. Bilateral cataract ex­tractions had been performed 5 years before presenta­tion; mere was also a history of lattice degeneration and dry eye syndrome. The patient denied smoking or alco­hol use. The family history was unremarkable for cancer, ocular, or neurologic disease. On neuro- ophthalmologic examination, the corrected visual acuities were 20/ 30- 2 OD and 20/ 20+ 2 OS. Color vision was normal OU. The pupils reacted briskly to light without an afferent defect. Goldmann perimetry was nor­mal OU. There was a moderate right abduction deficit. Maddox rod testing indicated a 10- diopter esotropia in primary gaze that increased to greater than 40 diopters in right gaze. Forced ductions were free. No proptosis or other abnormalities were noted. Mild sensory loss was present to the mid- calves; deep tendon reflexes were di­minished symmetrically ( 1+) throughout. Magnetic resonance imaging ( MRI) of the brain showed an enhancing soft tissue mass at the clivus with involvement of the right cavernous sinus ( Fig. 1A). A computed tomography ( CT) scan showed bony destruc­tion and anterior extension of tumor into the sphenoid sinus ( Fig. IB). The radiologic differential diagnosis in­cluded chordoma, metastatic disease, chondrosarcoma, and plasmacytoma. Thoracic and lumbar spine radio- TABLE 1. Neuro- ophthalmologic findings and radiology Patient Age Sex Examination Radiology 1 78 F Right VI nerve Clival mass* with palsy extension into right cavernous sinus 2 59 M Right VI nerve Clival mass with palsy, involvement of hypoglossal cavernous sinus, nerve palsy sphenoid sinus, and hypoglossal canals * Pathology of the intracranial tumors from both patients was con­sistent with plasmacytoma. Patient 1 satisfied criteria for the diagnosis of multiple myeloma; testing in this patient demonstrated a monoclonal paraprotein ( IgG kappa), skeletal lytic lesions, and bone marrow plas-macytosis. F, female; M, male. 242 SIXTH NERVE PALSY AS A SIGN OF INTRACRANIAL PLASMACYTOMA AND MULTIPLE MYELOMA 243 graphs showed collapse of the Til vertebral body ( Fig. 1C) with changes suggestive of a lytic process. A skeletal survey indicated involvement of the humeri and femora by lytic lesions; these findings were suspicious for mul­tiple myeloma. Serum protein electrophoresis ( SPEP) showed a prominent homogeneous band in the slow-gamma region, reacting on immunofixation as immuno­globulin G ( IgG) kappa. The concentration of parapro­tein, measured by densitometry, was 0.62 g/ dL. A 24- hour urine was positive for Bence- Jones proteins. Bone marrow biopsy showed a modest plasmacytosis with a focal cluster of plasma cells; the degree of plasmacytosis satisfied minor criteria for multiple myeloma. FIG. 1. Patient 1. A: Coronal T1- weighted magnetic resonance ( MR) image showing an enhancing soft tissue mass ( arrow) centered at the clivus with extension into the right cavernous sinus. B: Axial CT scan confirms the presence of bony destruc­tion by tumor and extension of tumor into the sphenoid sinus ( arrow). C: Radiographs of thoracic and lumbar spine showing collapse of the T11 vertebral body ( arrow) and changes con­sistent with a lytic process. An endoscopic sphenoidectomy with biopsy of the cli­vus mass was performed. Light microscopy of the tumor showed uniformly atypical plasma cells ( Fig. 2A). Im-munoperoxidase staining for immunoglobulin light chains confirmed kappa restriction ( Fig. 2B), consistent with plasmacytoma. Treatment was initiated with focal brain radiation therapy, followed by systemic chemo­therapy with melphalan and prednisone. Case 2 A 59- year- old man with a history of chronic obstruc­tive pulmonary disease and hypertension presented with a 2- week history of right occipital pain radiating to the / Neuro- Ophthalmol, Vol. 20, No. 4, 2000 244 T. Z. MOVSAS ETAL. ' FIG. 2. Patient 1. A: Hematoxylin and eosin stain of sphenoid sinus mucosa ( low power view) showing plasma cell infiltrate ( arrow). B: High- power examination shows uniformly atypical plasma cells; immunoperoxidase staining for light chains confirm Kappa restric­tion ( dark- staining cells). orbital region. This was accompanied by horizontal dip­lopia, epistaxis, and difficulty with tongue movements. The pain was dramatically increased by neck extension. There was no ptosis, jaw claudication, or amaurosis fugax. The patient had a 40- pack- year history of smok­ing. Family history showed lung cancer in the patient's mother, brother, and sister. Neuro- ophthalmologic examination showed corrected visual acuities of 20/ 20 OU. He perceived 9/ 10 HRR color plates correctly OU. Goldmann perimetry showed minimal constriction OU. The pupils were normal. A complete right abduction deficit was present. Alternate cover testing at distance showed a 15- diopter esotropia in primary gaze, which increased to 40 diopters in right gaze. The patient was able to protrude his tongue only minimally, and could not produce horizontal tongue movements to either side. An MRI of the brain with gadolinium showed an en­hancing mass involving the clivus with extension to the right cavernous sinus and sphenoid sinus ( Fig. 3). The hypoglossal canals were also involved. Endoscopic sphe-noidectomy with biopsy of the tumor showed findings consistent with plasmacytoma. Histopathology of the in­tracranial tumor was similar to that of patient 1 ( Fig. 2). Evaluation for possible multiple myeloma in this patient was negative, including a skeletal survey and bone mar­row biopsy. Focal brain radiation therapy was per­formed. DISCUSSION Although multiple myeloma commonly involves the nervous system, intracranial involvement is rare ( 1- 4). In 1932, Cushing ( 5) found that, among 2,000 intracranial tumors, only four cases had multiple myeloma. Clarke ( 6) has divided cranial myelomas into three groups. In group 1, the tumor involves the skull base and charac­teristically manifests with cranial nerve palsies. Group 2 tumors are termed " intracranial tumor syndromes," be­cause the myeloma extends into the parenchyma of the J Neuro- Ophthalmol, Vol. 20, No. 4, 2000 SIXTH NERVE PALSY AS A SIGN OF INTRACRANIAL PLASMACYTOMA AND MULTIPLE MYELOMA 245 FIG. 3. Patient 2. Axial T1- weighted MR image showing enhanc­ing mass involving the clivus ( arrow). The hypoglossal canals, cavernous sinus, and sphenoid sinus also show tumor involve­ment. brain, with or without involvement of the skull. Tumors in Clarke's group 3 are " intra- orbital tumor syndromes." By the 1950s, there were only 25 histologically verified cases of multiple myeloma associated with cranial nerve palsies ( 6). Fifteen of these 25 cases involved general­ized multiple myeloma, whereas the other 10 were ex­amples of solitary plasmacytomas. Our first patient ( patient 1) had widespread multiple myeloma with involvement of the base of skull, whereas the second patient had a solitary plasmacytoma. Solitary plasmacytomas, by definition, are confined to a single bone or extramedullary site without systemic manifesta­tions. In a study of 114 patients with solitary plasmacy­toma, approximately 70% were alive in 10 years ( 7). However, most ( 85%) had experienced disease progres­sion, indicating that most patients with solitary plasma­cytomas of bone eventually develop multiple myeloma. In contrast, most patients with extramedullary plasmacy­tomas, which commonly involve the head and neck re­gion, may be curable. Both of our patients presented with sixth nerve palsies. The sixth nerve, in fact, is the most common cranial nerve affected by multiple myeloma, followed by the fifth and eighth nerves ( 6). Our second patient also had paralysis of the tongue secondary to involvement of the hypoglossal ( 12th) nerves. Forett- Kaminsky et al. ( 8) re­ported a patient with isolated paralysis of the hypoglossal nerve secondary to tumor involvement of hypoglossal canal. The body of the sphenoid and the apex of the petrous pyramid are the most commonly involved sites for multiple myeloma affecting the skull ( 9). The differ­ential diagnosis for lytic clivus- based masses includes chordoma, metastatic disease, chondrosarcoma, and plas­macytoma. Less commonly, multiple myeloma may in­volve the region of the sella turcica and mimic a pituitary adenoma ( 10). Although radiation therapy is the primary treatment modality for solitary plasmacytomas, systemic chemotherapy may prolong survival in patients with multiple myeloma ( 11). Potential new therapies, includ­ing autologous stem cell transplantation, are under in­vestigation ( 11). Cranial nerve palsies, particularly sixth nerve paresis, may be initial presenting features of rare but treatable tumors, including plasmacytoma and multiple myeloma. When double vision associated with a sixth nerve palsy progresses beyond 1 week, a compressive cause should be strongly considered and neuroimaging performed. REFERENCES 1. Anonymous. Case records of the Massachusetts General Hospital. Weekly clinicopathologic exercises. Case 21- 1992. 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