In PAN, cysts are seen in all except –
**Question:** In PAN (Polyarteritis nodosa), cysts are seen in all except -
A. Liver
B. Kidneys
C. Brain
D. Heart
**Core Concept:** Polyarteritis nodosa (PAN) is a systemic small-vessel vasculitis characterized by inflammation of medium-sized muscular arteries and their branches. This leads to various clinical manifestations due to ischemia and tissue damage. Cysts are typically seen in different organs in PAN, and we need to identify the exceptions.
**Why the Correct Answer is Right:** In PAN, cysts are commonly found in the kidneys, lungs, gastrointestinal tract, and peripheral nerves. However, cysts are absent or less common in the heart and liver. Heart involvement is usually characterized by myocardial necrosis and fibrosis, leading to heart failure or arrhythmias. Cysts are not a typical finding in Polyarteritis nodosa affecting the heart.
**Why Each Wrong Option is Incorrect:**
A. Liver: Although PAN can affect the liver, cysts are not the typical finding in this condition. Hepatomegaly, hepatitis, and elevated liver enzymes are more common.
B. Kidneys: Cysts are present in the kidneys in PAN, so this option is incorrect. Renal involvement leads to hypertension, hematuria, and nephrotic syndrome.
C. Brain: Cysts in the brain are less common in PAN compared to other vasculitides like CNS vasculitis. Brain involvement in PAN is characterized by stroke-like episodes or leukoencephalopathy.
D. Heart: As mentioned earlier, cysts are not a typical finding in PAN affecting the heart. Heart involvement leads to heart failure, arrhythmias, or both.
**Clinical Pearl:** PAN is a vasculitic disorder that presents with a broad spectrum of clinical manifestations. It is essential to understand the usual organ involvement to differentiate it from other vasculitides and to guide appropriate management strategies. In contrast to other vasculitides, PAN typically affects medium and large arteries, causing ischemic or hemorrhagic complications.
**Correct Answer:** D. Heart - Cysts are not a typical finding in PAN affecting the heart. Heart involvement in PAN leads to heart failure, arrhythmias, or both.