Leptomeningeal and intraventricular myelomatosis manifesting an aggressive form of communicating hydrocephalus

Leptomeningeal myelomatosis (LMM) is a fatal complication that occurs in < 1% of patients with multiple myeloma. Many patients with LMM present with neurologic symptoms referable to cranial neuropathies, while the manifestation of communicating hydrocephalus has been underrecognized. A Japanese man with Bence Jones protein-κ multiple myeloma developed fever and headache at age 54 years. He then became somnolent and went into a coma. Neuroimaging analyses identified rapidly progressive communicating hydrocephalus due to meningitis. He died 83 days after the onset of headache without any response to treatment at age 55 years. No symptoms or signs associated with cranial nerves were found during the course of illness. Postmortem examination revealed hydrocephalus and diffuse infiltration of myeloma cells into the subarachnoid space of the cerebrum, cerebellum, and brainstem. In addition, the interstitial tissue of the choroid plexuses was filled with myeloma cells. These myeloma cells were positive for CD156 and light chain κ. The Ki-67 labeling index in myeloma cells of the central nervous system (CNS) was 30-40%. Histopathological examination further revealed many myeloma cells on the surface of the lateral, third and fourth ventricles and at the area postrema of the medulla oblongata. Patients with LMM can develop an aggressive form of communicating hydrocephalus. Given that cerebrospinal fluid, produced by epithelial cells in the choroid plexuses of the ventricles, passes into the subarachnoid space through the third and fourth ventricles, myeloma cells may invade the CNS through the choroid plexuses.

Dural plasmacytoma mimicking meningioma in a young patient with multiple myeloma

Intracranial involvement in multiple myeloma (MM) is rarely found, especially with dural involvement. There are only a few cases found concerning MM with intracranial involvement. MM usually involves an older group of patients. Cases involving young patients are very rare. The differential diagnosis of a dural plasmacytoma includes meningioma, metastasis, lymphoma and sarcoma of the dura mater. We present a young patient, 33 years old, with MM presenting an intracerebral mass mimicking meningioma on MRI. MM was diagnosed the previous year. The patient presented with headache, balance disturbance and back pain. MRI revealed an occipital extra-axial mass with a dural tail. Histopathological examination after excision showed MM. Published literatures on intracranial involvement of MM are also discussed. Plasmacytoma should be considered in the differential diagnosis of a solitary dural mass, particularly in a patient with MM.

Nonsecretory myeloma, immunoglobulin D myeloma, and plasma cell leukemia

Nonsecretory myeloma, which accounts for 1% to 5% of all myelomas, is characterized by the absence of detectable M-protein in serum and urine. The presenting features of nonsecretory myeloma are similar to those in patients with a detectable M-protein, except for the absence of renal function impairment. The response to therapy and survival of patients with nonsecretory myeloma are similar to those of patients with measurable M-protein. Immunoglobulin D myeloma represents 2% of all myelomas. Patients with IgD myeloma usually present with a small band or no evident M-spike on serum electrophoresis and heavy light-chain proteinuria. Thus, IgD myeloma can be considered a variant of Bence Jones myeloma; the presence of the IgD M-protein and the predominance of the lambda light chain are the only distinctive features. The median survival of patients with IgD myeloma is almost 2 years, with one fifth of them surviving for more than 5 years. Plasma cell leukemia is also a rare form of plasma cell dyscrasia (2% to 4% of all myelomas). The primary form accounts for 60% of the cases. In primary PCL, the constellation of adverse biologic prognostic factors in patients with advanced aggressive myeloma is already present at diagnosis. In fact, primary PCL has a more aggressive clinical presentation than MM, with a higher frequency of extramedullary involvement, anemia, thrombocytopenia, hypercalcemia, and renal failure. Treatment with a single alkylating agent plus prednisone is not appropriate. Combination chemotherapy with VAD, cyclophosphamide and etoposide, or VCMP/VBAP is a better initial option. Given the poor prognosis of primary PCL, intensification with high-dose therapy followed by stem cell rescue should be offered to affected patients.

[Neuromeningeal sites of multiple myeloma: 3 cases and review of the literature]

Neurologic manifestations are not unusual in multiple myeloma. Conversely meningeal and cerebral involvement have been very rarely reported. We report here on three patients with multiple myeloma and meningeal or cerebral involvement (two of them with autopsy study): one case of cerebellar involvement associated with secondary plasma cell leukemia and two cases of meningeal involvement. We reviewed the characteristics of 20 cases of meningeal involvement with demonstration of plasma cells at cerebrospinal fluid analysis (18 previously reported cases and our two patients). Meningeal involvement occurs in patients with initially stage III multiple myeloma in 85% of cases and is associated with the occurrence of plasma cell leukemia in 20% of cases. The most frequent neurologic signs are: confusion (60%), altered consciousness (25%), gait disorder (25%), cranial nerve palsy (25%). Meningismus is rarely present. Diagnosis is based on cerebrospinal fluid analysis after lumbar puncture which should be made after cranial magnetic resonance imaging. The diagnosis of intra-cranial haemorrhage and infectious meningitis have to be cautiously ruled out. Despite treatments (systemic and/or intrathecal chemotherapy, radiation therapy), prognosis is very poor: mean time of survival after the occurrence of neurologic signs is about 2 months.