Sample quiz

**Correct Answer:** D. Lymphangioleiomyomatosis (LAM)
The key to the question is a history of renal embolisation. Tuberous sclerosis is associated with both LAM and large renal angiomyolipomas, which are prone to haemorrhage and require embolisation for treatment. The cysts of LAM are also classically regular and diffuse.

**A. Birt-Hogg-Dubé syndrome:** While Birt-Hogg-Dubé is also associated with renal manifestations like RCC and oncocytomas, these are typically treated with surgical excision rather than embolisation. The cysts are also lower lobe predominant and irregular.
**B. Lymphoid interstitial pneumonia (LIP):** LIP is usually associated with autoimmune disorders (especially Sjögren's syndrome) or immunodeficiency (e.g., HIV/AIDS). The cysts are typically lower lobe predominant rather than diffuse.
**C. Neurofibromatosis type 1:** The renal association in NF1 is renal artery stenosis. Can cause upper lobe predominant cystic lung disease
**E. Idiopathic pulmonary fibrosis (IPF):** Presents with basal predominant fibrosis and honeycombing rather than as a cystic disease

C: The description lucencies with surrounding consolidation is highly suspicious of cavitating lesions in septic emboli. One of the common cause of which is infective endocarditis (the other being Lemierre syndrome, but inappropriate clinical context here). To confirm the diagnosis, an echocardiogram would be needed.
- **A: CT guided biopsy of the consolidation:** Biopsy is invasive and reserved for uncertain diagnoses; the clinical picture points clearly towards infection.
- **B: USG of liver:** Irrelevant in current clinical situation
- **D: USG guided drainage of pleural effusion:** The effusion is described as moderate without mediastinal shift, meaning it is not causing acute distress. Drainage would only be indicated if it were causing symptoms or an empyema was suspected.
- **E: Smoking cessation and CXR/CT monitoring:** This will be appropriate if the suspected diagnosis is Langerhans cell histiocytosis. It can occur in the current population, but less likely to lead to fever clinically. Also it demonstrates upper lobe predominance and does not commonly lead to pleural effusion.