A case with dyspnea and blurring of vision

A 63-year-old male presented with increasing fatigability and dyspnoea for 2 months, and headache and blurring of vision for past 15 days. Physical examination was significant for pallor, mild hepatomegaly and a palpable spleen (2 cm).
Labs showed:
Hemoglobin concentration of 4.0 g/dL
Total white cell count of 25000/cmm
Platelet count of 60000/cmm
Monoclonal gammopathy (M spike) was seen in gamma globulin region, which turned out to be IgM on immunofixation.
Fundus examination revealed venous dilatation, tortuosity and superficial retinal hemorrhages.

Diagnosis? Treatment?

This is a case of Waldenstroms macroglobulinemia! Treatment would be urgent plasmapheresis.

For those who don't know, Waldenstrom macroglobulinemia (WM) is a B-cell lymphoplasmacytic lymphoma. So the symptoms look like a lymphoma with hyperviscosity symptoms!

Initial symptoms of Waldenstrom macroglobulinemia:
Constitutional "B" symptoms
Bleeding
Lymphadenopathy
Hepatomegaly
Splenomegaly
Neurologic symptoms
Symptoms secondary to hyperviscosity (Blurring or loss of vision, headache, vertigo, nystagmus, dizziness, tinnitus, sudden deafness, diplopia, or ataxia)

Treatment of Waldenstrom Macroglobulinemia mnemonic:
If asymptomatic (Adequate hemoglobin and platelet levels): 
Observation.

If symptomatic WM:
Rituximab (either alone or with other agents)
Mnemonic: ABCD
Bortezomib
Bendamustine
Cyclophosphamide
Dexamethasone
Lenalidomide

Another mnemonic: Bored Walden Cycles with his Tuxedo and Bends on Lena and Dexa (Bortezomib, Waldenstroms, Cyclophosphamide, Rituximab, Bendamustine, Lenalidomide, Dexamethasone)

For patients who present with symptoms due to hyperviscosity:
Urgent plasmapheresis

That's all!
(PS: I made this case up.)
Other stuff is from UpToDate!
-IkaN