Abnormal B-cell morphologies have come up several times in the past papers. The college loves to ask about plasma cells in particular.  The usual trend is to ask for four or six different reasons as to why these cells may be seen in a blood film.

• Question 7.3 from the first paper of 2016
• Question 12.3 from the first paper of 2013
• Question 11.2 from the first paper of 2012
• Question 11.3 from the first paper of 2012

Plasmacytosis

Plasma cells swarming in the bloodstream can be a marker of numerous illnesses, and it is difficult to find just one article which might summarise the whole spectrum. In this Nature article, Table 2 lists several plasma cell disorders:

• MGUS
• Multiple myeloma
• Waldenström's macroglobulinemia
• Solitary plasmacytoma
• Systemic AL amyloidosis
• POEMS syndrome

A 1958 article reports on a few more causes:

• Adenocarcinoma of the colon
• Pulmonary tuberculosis
• Cirrhosis of the liver
• Aplastic anaemia
• Syphilis

The college answer to one of the recent CICM fellowship questions also includes the following causes, for which there is not much literature:

• Leprosy
• Varicella zoster infection
• Serum sickness

There are numerous others.

For instance, one article (recording the finding of peripheral plasmacytosis in a patient with Dengue fever) also mentions (and backs with references) the following causes:

• Primary infection and reactivation of Epstein–Barr virus
• Acute respiratory infections
• Parvovirus B19 infection
• Rubella
• Hepatitis virus A infection

Hypergammaglobulinaemia and hyperviscosity syndrome

If there is plasmacytoma, there is likely to be a monclonal gammopathy and hypergammaglobulinaemia. These extra gamma globulin molecules will be monoclonal immunoglobulins being produced by berserk out of control plasma cells. Waldenström's macroglobulinemia is the disorder where  clinically significant hyperviscosity occurs most frequently, according to this article by Mehta et al (2003). This is because Waldenström's macroglobulinemia is characterised by the excess production of IgM, which is a massive molecule.

Symptoms of hyperviscosity are presented in Question  7.3 from the first paper of 2016. They are as follows:

Features of the clinical presentation which suggest hyperviscosity:

• Severe headaches
• A fluctuating conscious state
• Stroke, seizures, coma (usually, venous cerebral infarction)
• Constitutional symptoms: fatigue, malaise, lethargy
• Haemorrhagic symptoms:  gingival or mucosal bleeding, or epistaxis.
• Blurred vision due to central retinal vein occlusion
• Headaches due to increased intracranial pressure (due to venous occlusion)
• Fundoscopy reveals dilated, tortuous retinal veins, as well as flame-shaped haemorrhages.
• Renal failure
• Aggravated heart failure (more difficult to pump the viscous blood)
• Priapism

Laboratory features:

• Leukocytosis, which suggests haematological malignancy
• An elevated plasma cell count
• An elevated globulin level (it will be mainly monoclonal IgM)

Management of the hyperviscosity syndrome is by plasmapheresis.

Smudge cell lymphocytes

Smudge cells are deformed lymphocytes which are associated with chronic lymphocytic leukaemia. Look, here's a whole bunch of them at the ASH Image Bank.