This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstetrical Ultrasonography in the Second Trimester, Subject name: Radiology
Snow storm appearance is seen in? 
Select and explain. 
A. Tubal pregnancy, B. Abdominal pregnancy, C. Hydatidiform mole, D. Fibroid
C: Hydatidiform mole
Answer: C: Hydatidiform mole 
Explanation: ANSWER: (C) Hydatidiform moleREF: Dutta obs 6th e p. 196Investigations used in H.moleultrasound* Snow storm appearance in uterus* Complete molar pregnancy (chorionic villi show diffuse hydropic swelling and absence of fetal shadow)* Some fetal tissue seen* For diagnostic purpose USG alone is adequate , hormonal assays are for post molar and post chemo follow upSerum beta HCG* Very high in molar pregnancy* > 40000 detected by R1A* Rapidly increasing levels suggest molar pregnancyChest X-ray* To rule out lung metastasisCT scan* To rule out brain and liver metastasis