The likely diagnosis in this case is Haemolytic Uremic Syndrome (HUS), which is generally seen in young children presenting with a triad of symptoms, namely: acute renal failure, microangiopathic haemolytic anaemia, and thrombocytopenia. The typical cause of HUS is ingestion of a strain of Escherichia coli. The laboratory results will usually include fragmented RBCs, decreased serum haptoglobin, reduced platelet count, nonspecific WBC changes, and normal coagulation tests (PTT included).

The upper motor neurone signs in this patient point towards a diagnosis of spinal cord compression above the level of L1 and rules out cauda equina syndrome.

Spinal cord compression is an oncological emergency and affects up to 5% of cancer patients. Extradural compression accounts for the majority of cases, usually due to vertebral body metastases. One of the most common causes of spinal cord compression is osteoarthritis. It is also more commonly seen in patients with lung, breast, or prostate cancer.

Clinical features include:
1. Back pain: the earliest and most common symptom, may worsen on lying down or coughing
2. Lower limb weakness
3. Sensory changes: sensory loss and numbness
4. Neurological signs: depending on the level of the lesion.
Lesions above L1 usually result in upper motor neurone signs in the legs. Lesions below L1 usually cause lower motor neurone signs in the legs and perianal numbness. Tendon reflexes are increased below the level of the lesion and absent at the level of the lesion.

Management options are:
1. High-dose oral dexamethasone
2. Urgent MRI for consideration of radiotherapy or surgery

Waldenström’s macroglobulinemia (also called lymphoplasmacytic lymphoma) is an uncommon type of non-Hodgkin lymphoma seen in older people. It is a lymphoplasmacytoid malignancy characterised by the secretion of a monoclonal IgM paraprotein. Its features include weight loss and lethargy; monoclonal IgM paraproteinemia; hyperviscosity syndrome leading to bilateral central retinal vein occlusion (CRVO) and hence, visual disturbances; hepatosplenomegaly and lymphadenopathy; and cryoglobulinemia. It is not, however, associated with bone pain.

Multiple myeloma presents with bone pain usually in the back or at the level of the ribs. Pathological fractures are common. The patient usually experiences fatigue, paleness, weakness, dyspnoea and gastro-intestinal complaints such as nausea and constipation. Characteristic for this case is the presence of many plasma cells in the peripheral blood smear.

Diagnosis of multiple myeloma (MM) is based on the confirmation of (a) one major criterion and one minor criterion or (b) three minor criteria in an individual who has signs or symptoms of multiple myeloma.

Major criteria:
1. >30% plasma cells on bone marrow biopsy
2. Monoclonal band of paraprotein on electrophoresis: >35g/L for IgG, 20g/L for IgA, or >1g of light chains excreted in the urine per day

Minor criteria:
1. 10-30% plasma cells on bone marrow biopsy
2. Abnormal monoclonal band but levels less than listed above
3. Lytic bone lesions observed radiographically
4. Immunosuppression

Subcutaneous (S/C) low-molecular-weight heparin (LMWH) is a preferred anticoagulant in pregnancy. Warfarin is contraindicated due to its teratogenic effects, especially in the first trimester and at term.

Pregnancy is a hypercoagulable state with the majority of VTE incidents occurring in the last trimester.

Hypercoagulability in pregnancy is caused by:
1. Increase in factors VII, VIII, X, and fibrinogen
2. Decrease in protein S
3. Uterus pressing on IVC causing venous stasis in legs

Management options include:
1. S/C LMWH preferred to IV heparin (less bleeding and thrombocytopaenia)
2. Warfarin contraindicated

CML is a myeloproliferative disorder involving neoplastic proliferation of mature myeloid cells, especially granulocytes and their precursors. The non-acute symptoms of marked splenomegaly and anaemia accompanied by of fever and abdominal discomfort rules out the other conditions.

Leukemoid reaction has a high LAP score.

Leukemoid reaction refers to leucocytosis occurring as a physiological response to stress or infection which may be mistaken for leukaemia, especially chronic myeloid leukaemia (CML). Leucocytosis occurs, initially, because of accelerated release of cells from the bone marrow and is associated with increased count of more immature neutrophils in the blood (left-shift). In order to differentiate, LAP score is used. Leukocytic alkaline phosphatase (ALP) activity is high in a leukemoid reaction but low in CML.

LAP score is high in:
1. Leukemoid reaction
2. Infections
3. Myelofibrosis
4. Polycythaemia rubra vera
5. Steroids, Cushing’s syndrome
6. Pregnancy, oral contraceptive pill

LAP score is low in:
1. CML
2. Pernicious anaemia
3. Paroxysmal nocturnal haemoglobinuria (PNH)
4. Infectious mononucleosis

This is a case of Vit. B12 or folic acid deficiency. The anaemia with angular stomatitis is highly suggestive of Vit. B12 or folate deficiency. The absence of koilonychia excludes Iron deficiency anaemia.

Haemochromatosis is an abnormally high rate of the production of haemoglobin. It is an autosomal recessive disease copied on chromosome 6. It is associated with hepatic disorders, cardiac diseases and skin pigmentation. It is treated by regular venesection.