USG findings of focal anechoic lesion with floating membranes indicated toward which liver pathology?

Ans. is 'd' i.e., Hydatid cyst * As the Hydatid cyst matures, the endocyst starts detaching from the wall of the cyst and appears as an undulating, floating membrane. Complete detachment of the endocyst is seen as the "water lily sign"* Solitary hypoechoic /anechoic lesion without septae or debris can occur in early stage of evolution of hydatid cyst (Type 1 / Simple cyst). However, the diagnosis of hydatid cyst may be considered when focal thickening of the wall is present or when fine hyperechoic spots, due to the hydatid sand, appear in the dependent areas.Remember* Solitary hypoechoic aseptate lesion - Simple liver cyst* Solitary hypoechoic aseptate lesion with hyperechoic spots due to hydatid sand - Type 1 (simple) hydatid cystIntrahepatic hydatid cyst* Liver is the most common site for hydatid cyst (2nd most common site is lung).* The sonographic appearance of hydatid cysts is correlated with its evolution and six classes may be identified: -1. Type 1 (Simple cyst) Single (solitary) hypoechoic/anechoic aseptate (without septa) lesion. The diagnosis of hydatid cyst may be considered when focal thickening of wall is present or when hyperechoic spots, due to hydatid sand, appear in the dependent areas.2. Type 2 (septate):- Multilocular cyst with septa (septate).3. Type 3:- Cyst with membrane detachment.4. Type 4:- Cyst with mixed (solid and cystic) echo structures.5. Type 5:- Heterogenous cyst, i.e., inconstant echo structure, with progressive reduction of the liquid component, with thickening of the wall that becomes hyperechoic.6. Type 6 (Calcified cyst):- Hyperechoic lesion with strong shadowing.