**Question:** Cancer caused by chronic parasitic infection -

A. Hepatocellular carcinoma due to Hepatitis B and C virus infection
B. Leishmaniasis-induced mucocutaneous leishmaniasis
C. Schistosomiasis-induced bladder cancer
D. Strongyloides stercoralis infection and lung cancer

**Correct Answer:** C. Schistosomiasis-induced bladder cancer

**Core Concept:** Chronic parasitic infections can lead to the development of cancer.

**Why the Correct Answer is Right:**
Schistosomiasis is a parasitic infection caused by Schistosoma species, particularly S. haematobium, which affects the urinary, gastrointestinal, and cardiovascular systems. One of the complications of schistosomiasis is bladder cancer, particularly transitional cell carcinoma. The parasite penetrates the bladder mucosa, causing chronic inflammation and tissue damage, which leads to the development of bladder cancer over time.

**Why Each Wrong Option is Incorrect:**

A. Hepatocellular carcinoma is caused by Hepatitis B and C virus infections, not parasitic infections. Although parasitic infections like schistosomiasis can lead to liver cirrhosis, which increases the risk of hepatocellular carcinoma, the primary cause is viral infection.

B. Leishmaniasis is caused by Leishmania parasites, leading to cutaneous, mucosal, or visceral leishmaniasis. Leishmaniasis does not directly cause cancer but can lead to tissue damage and inflammation, which may increase the risk of secondary malignancies.

D. Strongyloides stercoralis infection primarily affects the gastrointestinal system and is associated with hyperinfection syndrome and disseminated Strongyloides infection. Strongyloides does not directly cause cancer in the lungs, but it can cause respiratory symptoms and complications.

**Clinical Pearl:** Chronic parasitic infections can indirectly increase the risk of cancer through tissue damage, inflammation, and immunosuppression. However, cancer directly caused by parasitic infections is relatively uncommon. In the case of schistosomiasis, the tissue damage and inflammation lead to the development of bladder cancer over time.