Fatigue and weight loss in a 45-year-old man
Mr. Samuel Okafor, 45, presents with six weeks of fatigue, reduced appetite, and unintentional weight loss of 6 kg (from 88 kg to 82 kg). He also reports intermittent low back pain, occasional night sweats, and a "heavy" feeling in his left upper abdomen. He has no fever, no jaundice, and no change in bowel habit. He works as a long-distance truck driver, drinks about 20 standard drinks per week, and smokes 10 cigarettes daily. He takes no regular medications. He has not seen a doctor in five years. Observations: BP 138/86, HR 88, temperature 36.9°C, weight 82 kg. He appears tired but not cachectic. His abdomen is soft with mild left upper quadrant fullness; there is no palpable organomegaly on brief examination, and no lymphadenopathy.
1. What is your differential diagnosis, and what features in the history raise or lower your concern?
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Differential diagnosis:
- Malignancy: haematological (lymphoma, leukaemia, myeloma) given night sweats, fatigue, and weight loss; gastrointestinal (colorectal, gastric, pancreatic, oesophageal); lung cancer given his smoking history; renal cell carcinoma; prostate cancer less likely at 45 but possible.
- Chronic infection: tuberculosis (relevant given night sweats and weight loss, and his occupational exposure to many communities as a truck driver), HIV, hepatitis B or C, endocarditis.
- Inflammatory or autoimmune: inflammatory bowel disease, coeliac disease, vasculitis, sarcoidosis.
- Endocrine and metabolic: diabetes, hyperthyroidism, adrenal insufficiency.
- Haematological non-malignant: anaemia from any cause, including iron deficiency from occult gastrointestinal blood loss.
- Psychosocial: depression, alcohol-related harm, occupational stress and poor diet on the road.
Features raising concern: unintentional weight loss of 6 kg (about 7% of body weight) over six weeks, night sweats, fatigue, left upper quadrant fullness suggesting splenomegaly, long interval without medical review, smoking, and significant alcohol intake.
Features lowering concern: no fever, no jaundice, no lymphadenopathy, no cachexia, no bowel change, and a plausible lifestyle explanation for some fatigue.
Reasoning: Weight loss plus night sweats is a constitutional symptom pattern that mandates systematic exclusion of malignancy and chronic infection. The exam tests whether you generate a broad but prioritised differential rather than anchoring on stress or alcohol.
2. Outline your investigation plan and the reasoning behind each test.
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First-line investigations:
- Full blood count and film: anaemia, thrombocytopenia, leucocytosis or leucopenia, and blood film for haematological malignancy.
- Urea, electrolytes, creatinine, and liver function tests: renal impairment, hepatic involvement, and alkaline phosphatase elevation that might suggest bone or liver disease.
- Inflammatory markers (CRP, ESR): support infection, inflammation, or malignancy; a very high ESR raises myeloma or giant cell arteritis considerations.
- Blood glucose and HbA1c: diabetes is common and causes weight loss and fatigue.
- Thyroid function tests: hyperthyroidism causes weight loss and fatigue.
- Iron studies, vitamin B12, and folate: iron deficiency may signal occult gastrointestinal blood loss.
- Coeliac serology: a common cause of weight loss and fatigue.
- HIV and hepatitis B and C serology: chronic infection and relevant to his risk profile.
- Urinalysis: haematuria suggesting renal malignancy; proteinuria.
- Chest X-ray: smoking history, night sweats, possible tuberculosis or lung malignancy.
Second-line or targeted:
- Abdominal ultrasound: to assess the left upper quadrant fullness and look for splenomegaly, hepatomegaly, lymphadenopathy, or renal masses.
- Faecal immunochemical test or colonoscopy referral: given weight loss and possible iron deficiency, gastrointestinal investigation is warranted; the choice depends on local pathways and results.
- Serum protein electrophoresis and free light chains: if myeloma is suspected (back pain, anaemia, high ESR, renal impairment).
- Tuberculosis testing (interferon-gamma release assay, chest imaging): given night sweats and occupational exposure.
- Age-appropriate cancer screening review: bowel, and discuss prostate screening.
Reasoning: The plan moves from broad screening to targeted investigation, is driven by the constitutional symptoms, and avoids both over-investigation and premature reassurance. Each test is justified by a specific diagnostic hypothesis.
3. How do you discuss the possibility of a serious diagnosis with him, and what safety-netting and follow-up do you arrange?
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Framing the conversation:
- Start with what you have noticed and why it matters: "Your weight loss and night sweats are the kind of symptoms we take seriously, so I want to investigate them properly rather than assume it is stress."
- Be honest but not alarming: explain that there are several possible explanations, including infection, inflammation, and less commonly more serious conditions, and that tests are needed to narrow this down.
- Avoid premature reassurance ("I'm sure it's nothing") and avoid catastrophic framing. Use a balanced statement: "We don't know yet, and the tests will tell us much more."
- Explore his concerns and what he is most worried about; ask about work and driving, since a diagnosis could affect his livelihood and he may need to plan.
- Discuss the practicalities: which tests, when results will be available, how he will be contacted, and what to do if symptoms worsen.
Safety-netting:
- Advise urgent review if he develops fever, worsening pain, jaundice, vomiting, black or bloody stools, new lumps, breathlessness, or rapid further weight loss.
- Give written information and a clear contact pathway, including after-hours options.
- Specifically ask him to return if he cannot eat or drink or feels increasingly unwell.
Follow-up:
- Book a review within one to two weeks to discuss results, and ensure results are tracked rather than left to the patient to chase.
- Arrange early review of any abnormal result with a clear referral pathway (haematology, gastroenterology, or oncology as indicated).
- Address modifiable factors in parallel: alcohol reduction, smoking cessation support, diet and sleep on the road, and mental health screening.
- Document the discussion, the differential, and the safety-net advice.
Reasoning: The exam tests honest communication under uncertainty, avoidance of false reassurance, and a concrete follow-up system - the elements that distinguish safe practice from a reassuring but unsafe consultation.