Tuberculosis and lung cancer quiz Flashcards
During a routine pre-employment health check, Ms. Gangarosa, a 47 year old woman, has a screening chest x-ray that reveals a 4 cm mass on her right lung. Chest x-ray from 3 years ago was normal. Ms. Gangarosa does not smoke and has never smoked, and she has no exposure to second hand smoke. She works at a local hardware store and has no significant past medical, surgical or travel history. She has no family history of cancer. The patient undergoes surgery and pathological examination of the lesion reveals a primary lung cancer. Which of the following is the most likely type of cancer in this patient?
a) Broncho-alveolar carcinoma
b) Bronchogenic adenocarcinoma
c) Large cell anaplastic carcinoma
d) Small cell carcinoma
e) Squamous cell carcinoma
The correct answer is b- Bronchogenic adenocarcinoma
Bronchogenic adenocarcinoma is only weakly associated with smoking – this cancer
Both bronchoalveolar and large cell(anaplastic) carcinoma are relatively rare
Small cell lung carcinoma is very strongly associated with smoking and is also more uncommon compared with squamous and bronchogenic adenoma carcinoma – about 10% cases
Squamous cell occurs approximately as frequently as bronchogenic adenocarcinoma but is very strongly associated with smoking
During a routine pre-employment health check, Ms. Gangarosa, a 47 year old woman, has a screening chest x-ray that reveals a 4 cm mass on her right lung. Chest x-ray from 3 years ago was normal. Ms. Gangarosa does not smoke and has never smoked, and she has no exposure to second hand smoke. She works at a local hardware store and has no significant past medical, surgical or travel history. She has no family history of cancer. The patient undergoes surgery and pathological examination of the lesion reveals a primary lung cancer. Which of the following is the most likely type of cancer in this patient?
a) Broncho-alveolar carcinoma
b) Bronchogenic adenocarcinoma
c) Large cell anaplastic carcinoma
d) Small cell carcinoma
e) Squamous cell carcinoma
the correct answer is d - Because the apices have a higher alveolar pO2
This presentation is classic for reactivation of pulmonary TB. The high PO2 found in the upper portion of the lungs provides a favourable environment for growth of Mycobacterium tuberculosis in reactivation TB. In contrast, primary TB tends to occur in the middle and lower lobes where small infectious particles lodge after being inhaled.
The apices have less perfusion relative to ventilation, i.e. V/Q ratio >1, and relative to the bases have less perfusion in general(not more).
pH of blood at the apices is higher c/w bases – i.e. more alkalotic- because of the relatively higher ventilation leading to lower pCO2 and hence localized respiratory alkalosis in blood leaving those alveoli.
Regional differences in macrophage concentrations have not been described to affect TB reactivation
QUESTION THREE
Dr de Silva, a junior doctor who recently immigrated from Sri Lanka planning to work in the NHS, presents to her GP with fatigue, malaise and cough of one month’s duration occasionally productive of rust-coloured sputum. Dr de Silva has also noted 3 kg weight loss in the last month. She does not smoke or have any significant occupational exposures. Her only medications are oral contraceptives. Her GP arranges for a chest x-ray, image shown. The radiologist phones the GP because she is concerned about the abnormalities shown by the arrows.
Q3a: What is the most likely diagnosis in this patient?
Patient’s symptoms and chest x-ray suggest primary TB
Q3b: What type of abnormality(s) does the chest x-ray show? Describe in detail.
Ghon foci – little arrow;
Enlarged hilar lymph nodes – big arrow –
together called a Ghon COMPLEX. Consistent with primary TB (vs reactivation TB)
Q3c: What are risk factors for the disease Dr de Silva most likely has? – list a minimum of three (they do not have to be specific to Dr de Silva)
- Non-UK born/recent migrants - Recent arrival or travel
- HIV
- Other immunocompromise states (i.e. cancers)
- Homeless
- Drug users, prison inmates
- Close contacts of patients with TB
Q3d: The disease Dr de Silva has can spread outside the lungs and affect the adrenal glands leading to primary adrenocortical insufficiency. If this were to occur in Dr de Silva what symptoms and signs would we expect?
In places where TB is endemic it remains a major cause of primary adrenocortical insufficiency (Addison’s disease). Signs and symptoms include: progressive weakness, fatigue, poor appetite, salt craving ,weight loss, dizziness with orthostasis due to hypotension; hypotension, skin hyper pigmentation, labs tests may show hyponatremia and hypoglycaemia
Q3e: Dr de Silva is seen by a multidisciplinary team including a Respiratory Consultant and placed on multi-drug therapy for TB.
Please list the four first line medications used to treat TB, and for each medication one described side effect
• Rifampicin - Raised transaminases & induces cytochrome P450 - Orange secretions / urine • Isoniazid - Peripheral neuropathy (prevent with pyridoxine 10mg od) - Hepatotoxicity • Pyrazinamide - Hepatotoxicity • Ethambutol - Visual disturbance
A 74-year-old man has had confusion for 2 weeks. An x-ray of the chest shows a 5-cm mass in the lung. Laboratory studies of serum show: Na+ 110 mEq/L Cl- 72 mEq/L K+ 4.5 mEq/L HCO3 30mEq/L Glucose 200 mg/dL Creatinine 1.4 mg/dL
Which of the following is the most likely cause of these findings?
a) Adenocarcinoma of the lung
b) Large cell anaplastic carcinoma
c) Broncho-alveolar carcinoma
d) Renal cell carcinoma metastatic to the lung
e) Small cell carcinoma of the lung
The correct answer is e – small cell carcinoma of the lung
Paraneoplastic Syndrome of Inappropriate Antidiuretic Hormone(SIADH) is most commonly caused by Small Cell Carcinoma of the lung – and approximately 10% to 45% of all patients with small cell lung cancer develop SIADH.
A 45 y/o woman born in Somerset (UK) presents with two months history of productive cough, malaise, fatigue, weight loss, haemoptysis, and finger clubbing. She has smoked one pack/day for 35 years. Her chest x-ray is shown. What is the most likely diagnosis?
a) Metastatic glioblastoma b) Sarcoidosis
c) Tuberculosis
d) Pneumonia
e) Primary bronchogenic carcinoma
- The correct answer is e- Primary bronchogenic carcinoma
- Chest x-ray demonstrates a large left hilar mass which is most likely due to a bronchogenic carcinoma in this clinical context.
- The clinical features do not point towards active infection, and the chest x-ray is not typical for either primary or reactivation TB. However, on the grounds of the image alone the diagnosis of TB, or other atypical lung infection can not be excluded.
- Sarcoidosis usually causes bilateral hilar enlargement.
- Glioblastoma metastases outside the central nervous system is rare.
Mr Thatcher, a 40-year-old man recently diagnosed with HIV+, has the chest x-ray shown below. He denies any cough, haemoptysis, fevers or chills; his physician carries out a Tuberculin Skin Test (TST) that is negative, and then an interferon gamma releasing assay(IGRA) that is also negative. What would be an appropriate medical management plan for Mr Thatcher with regards to this chest x-ray finding?
a) No medical management plan is required as Mr. Thatcher
has no respiratory symptoms and his TST and IGRA are both negative
b) Mr. Thatcher should return for a repeat chest x-ray in three months and if it is unchanged no further medical management plan is required
c)Mr. Thatcher should collect three early morning sputum samples and send them for Ziehl-Neelsen (ZN) stain; if negative no further
medical management plan is required
d) Mr. Thatcher should be referred for consideration of treatment of latent tuberculosis
e) Mr. Thatcher should be referred for consideration of treatment of active tuberculosis
The correct answer is d- Refer Mr. Thatcher for consideration of treatment of latent tuberculosis (prophylaxis)
• Mr. Thatcher’s +HIV immunocompromises him and that may be why both his TST & IGRA are negative despite his chest x-ray being highly suggestive of previous primary TB infection. Sputum gram stain only picks up 60-70% of patients with active TB – and sensitivity would be further reduced in a patient not coughing or otherwise symptomatic (i.e. latent).
• In a patient who is immunocompromised but with history/chest x-ray consistent with TB NICE guideline states that if TST&IGRA negative “If this assessment is negative, offer them treatment for latent TB infection”(NICE; https://www.nice.org.uk/guidance/ng33/chapter/ Recommendations#latent-tb).
• Mr Thatcher would need to be assessed for TB risk factors as there are other things that can give these chest x-ray findings so the final decision on treatment would include clinical judgement and patient’s wishes.
• As Mr Thatcher is asymptomatic he would not be treated for active TB
Mr. Smith, a 72 y/o widower living alone at home, is brought to his GP by his daughter because she is concerned that he seems confused for the last several weeks. The patient appears comfortable and is oriented to person and place, though not date. The patient also states that he has had a constant, severe headache for the last several weeks, and a dry cough. All of the symptoms began gradually. Mr. Smith’s past medical history is significant for stage IIB lung cancer diagnosed 18 months ago for which he underwent surgery. He denies fever, chills or myalgias but states he has been feeling tired. The most likely diagnosis to consider in Mr. Smith is which of the following?
a) A primary brain tumour
b) Lung cancer metastatic to the brain
c) Meningitis
d) Hypoxaemia secondary to pneumonia
e) Cerebrovascular accident
The correct answer is e- Yes, it is appropriate because there is high prevalence of lung cancer in patient populations with Ms. Laurel’s smoking history, early detection improves patient outcomes and she is within the screening range 55-74 y/o.
The relative radiation dose from CT chest is low and the risk to benefit ratio favours benefit in patients with a high risk for developing lung cancer – Ms. Laurel’s smoking history places her in a high risk group. A recent study showed CT screening reduced lung cancer mortality by 26% in men and between 39% and 61% in women.
The age for CT chest screening in the UK is 55-74 and Ms. Laurel’s excellent functional status (as indicated by her work and activities) means that she would be a good surgical candidate if an early lung cancer were detected.
Monitoring of an abnormal lesion on CT chest would not be appropriate in this relatively healthy patient who is a good surgical candidate because of risk of disease progression.
Mr. Smith, a 72 y/o widower living alone at home, is brought to his GP by his daughter because he has had several falls at home, back pain, and intermittent foecal and urinary incontinence over the past two weeks. The patient is oriented to person, place and time. He states that his legs feel weak, and that sitting on the hard chair in the GPs office is exacerbating his back pain. Otherwise, his only new complaints are of fatigue and 3 kg weight loss in the last month. Mr. Smith’s past medical history is significant for stage IIB lung cancer diagnosed 18 months ago for which he underwent surgery. He denies fever, cough or chills. The most likely diagnosis to consider in Mr. Smith is which of the following?
a) Lung cancer metastatic to the brain
b) Lung cancer metastatic to the spinal with progressive spinal cord compression
c) Hypoxaemia secondary to pneumonia
d) Cerebrovascular accident
e) Severe spinal stenosis with progressive spinal cord compression
The correct answer is b- Lung cancer metastatic to the spine with progressive cord compression.
One of the main sites to which lung cancer metastasizes is the bone and this includes the bones protecting the spinal cord (vertebrae). The clinical case is a typical presentation for spinal metastasis with partial cord compression as evidenced by lower extremity weakness and fecal and urinary incontinence. This is a medical emergency as spinal metastases creating partial cord compression can rapidly cause full paralysis in many cases. Emergency management may include radiotherapy and surgery depending on the patient’s wishes and prognosis.
Mr. Smith, a 72 y/o widower living alone at home, is brought to his GP by his daughter because she is concerned that he seems confused for the last several weeks. The patient appears comfortable and is oriented to person and place, though not date. The patient also states that he has had a constant, severe headache for the last several weeks, and a dry cough. All of the symptoms began gradually. Mr. Smith’s past medical history is significant for stage IIB lung cancer diagnosed 18 months ago for which he underwent surgery. He denies fever, chills or myalgias but states he has been feeling tired. The most likely diagnosis to consider in Mr. Smith is which of the following?
a) A primary brain tumour
b) Lung cancer metastatic to the brain
c) Meningitis
d) Hypoxaemia secondary to pneumonia
e) Cerebrovascular accident
The correct answer is b- Lung cancer metastatic to the spine with progressive cord compression.
One of the main sites to which lung cancer metastasizes is the bone and this includes the bones protecting the spinal cord (vertebrae). The clinical case is a typical presentation for spinal metastasis with partial cord compression as evidenced by lower extremity weakness and fecal and urinary incontinence. This is a medical emergency as spinal metastases creating partial cord compression can rapidly cause full paralysis in many cases. Emergency management may include radiotherapy and surgery depending on the patient’s wishes and prognosis.
