Dr Behzad Rafiee is a GP in Brisbane , Queensland .

He has previously seen a chest physician who attributed the symptoms to mucus in retropharynx . He was then sent to an ENT specialist who suspected a combination of GORD , obstructive sleep apnoea and being overweight as the explanation .

Jim cycles regularly and reports no shortness of breath . He is a recreational scuba diver and has had normal lung function tests for his dive medicals . He has no history of lung injury or pneumonia .

He smoked briefly when aged 18-19 , and he drinks alcohol occasionally .

Some of Jim ’ s work requires welding and grinding in a shed , and he is sometimes exposed to welding fumes . The shed has a

good ventilation , and he usually wears a protective mask . His past medical history includes hypercholesterolaemia , migraine , colonic polyps , carpal tunnel release , mild obstructive sleep apnoea , and medically managed coronary artery disease .

He is on daily aspirin 100mg , fenofibrate 145mg and composite ezetimibe 10mg rosuvastatin 10mg and omega-3 .

On examination , Jim appears well and vital signs are within normal limits . Cardiorespiratory examination is unremarkable , with no audible adventitious breath sounds . ENT examination is also normal .

Jim is referred to another chest physician , who orders a CT chest that shows bibasal atelectasis likely reflecting post inflammatory / infectious change and heavy coronary artery calcification ( consistent with known CAD ).

Respiratory function tests are within normal limits , although the fractional exhaled nitric oxide ( FeNO ) is borderline for asthma .

The chest physician feels GORD and vocal cord pathology remain the most likely cause of the crackles , so a retrial of PPI is recommended , followed by ENT review if no further improvement . Jim is also prescribed budesonide / formoterol inhaler for possible mild asthma .

Progress

After the respiratory review , the patient presents to another GP to discuss the outcome

of this specialist consult . At this visit , the GP reviews Jim ’ s history and notices that he has had increased lymphocytes in the last couple of years ( see table 1 ), with otherwise normal FBC .

Jim denies any B symptoms and there is no lymphadenopathy or hepatosplenomegaly on examination . The GP requests additional blood tests , including lymphocyte surface marker studies , protein electrophoresis and free light chain . The protein studies demonstrate an IgM paraprotein , and the peripheral blood surface markers demonstrate a monoclonal B-cell population . The phenotype is : CD5 + ve CD10 -ve CD19 + ve CD20 + ve ( weak ) CD23 + ve CD79b -ve CD200 + ve CD43 + ve SMIg Kappa ( weak ).

The pathologist reports this is most consistent with high count monoclonal B-cell lymphocytosis ( MBL ) with a chronic lymphocytic leukaemia ( CLL ) -like phenotype .

A haematologist confirms the diagnosis of MBL with associated IgM paraprotein . Given the absence of active symptoms , observant management is recommended . However , given there is an increased risk of progression to chronic lymphocytic leukaemia in subgroups of MBL with this phenotype , regular clinical and FBC / blood surface marker monitoring is recommended .

Discussion

MBL is characterised by the presence of clonal B cells in the peripheral blood in the absence any features of B-cell lymphoproliferative

disorder ( unintentional weight loss , significant fatigue , fever , night sweats , lymphadenopathy , splenomegaly , hepatomegaly ), autoimmune disorder or infectious disease . 1 , 2

The reported prevalence of the condition varies from 1 % to 18 %, depending on the population studied and assay sensitivity . 3 Males are more likely to be affected than females ( 1.5:1 ), and incidence increases with age from less than 1 % in those younger than 40 years , up to 75 % in those 90 and older . 2 , 3

Cases are categorised based on immunophenotypical features , which in turn predicts the risk of progression to chronic lymphocytic leukaemia . Subtypes include CLL-like MBL , MBL