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Q1: What diagnosis is suggested by the raised plasma viscosity and monoclonal IgM band and how would you confirm this?
The diagnosis is Waldenstrom's macrogolulinaemia. A raised plasma viscosity and IgM monoclonal band of greater than 3 g/l are strongly suggestive of a lymphoplasmacytoid malignant lymphoma. This condition is commonly referred to as Waldenstrom's macroglobulinaemia and was first described in 1944.1 Other lymphoproliferations which may rarely secrete an IgM paraprotein include low grade non-Hodgkin's lymphoma and multiple myeloma plasmacytoma. The disease usually develops in the seventh decade and in the early stages it typically presents with lethargy, weight loss, recurrent infections, and features of hyperviscosity (epistaxis, visual disturbance, peripheral neuropathy, headache, altered consciousness, or congestive cardiac failure). Unlike myeloma, Waldenstrom's macroglobulinaemia does not result in lytic bone lesions. The diagnosis is confirmed by bone marrow examination, which (as in our patient) shows an excess of lymphoplasmacytoid cells.
Q2: What is the likely explanation for the lung mass?
A pulmonary deposit of lymphoplasmacytoid malignant lymphoma is the likely explanation for the lung mass. Lung involvement in Waldenstrom's macroglobulinaemia has been documented but is uncommon, occurring in fewer than 5% of cases. Bollinelli et al described five forms of pulmonary involvement—namely, infectious manifestations, parenchymal involvement, discrete pulmonary deposits (as in this patient) which may be single or multiple, bronchial infiltration, and pleural involvement.2 In patients who develop pulmonary lesions, two thirds will have radiographic abnormalities at presentation.3
A trucut biopsy of the lung mass in this patient revealed a heavy infiltrate of plasma cells consistent with a localised deposit of lymphoplasmacytoid malignant lymphoma.
Q3: What treatment would you consider?
As Waldenstrom's macroglobulinaemia is incurable, treatment is only indicated in symptomatic cases. Plasmapheresis is effective for short term control of hyperviscosity and its associated symptoms. The oral alkylating agent chlorambucil is effective in controlling the disease and there are reports of its successful use in cases with pulmonary involvement,4 5 although treatment for 12 months may be required before an adequate response is obtained. Treatment with combinations of chemotherapeutic agents has also been found to be effective.
In view of her hyperviscosity, our patient was admitted to hospital for plasmapheresis, ultimately requiring eight sessions. As treatment for her underlying macroglobulinaemia she received chemotherapy with six cycles of the nucleoside analogue fludarabine (25 mg/m2daily for five days, repeated every four weeks). There was a marked improvement in the appearances of the chest radiograph (see fig 1below) and the patient is now symptom free. Plasma viscosity fell to 1.85 mpa/s with an IgM monoclonal band of 5 g/l. Maintenance therapy has been given with chlorambucil. We know of no other reported cases of Waldenstrom's macroglobulinaemia with pulmonary involvement that have successfully treated with fludarabine.
Waldenstrom's macroglobulinaemia presenting with a pulmonary deposit of lymphoplasmacytoid malignant lymphoma.
Pulmonary involvement is a rare feature of Waldenstrom's macroglobulinaemia
Pulmonary features may be the first sign of the disease
Treatment is palliative and may include plasmapheresis and chemotherapy