Which CCAM type is described as multiple micro cysts that appear as a solid mass on imaging?

Which CCAM type is described as multiple micro cysts that appear as a solid mass on imaging?

• A. Type I
• B. Type II
• C. Type III
• D. Type IV

Answer: (C)

Type III CPAM is defined by a predominance of microscopic cysts that are too small to resolve on ultrasound, so the lesion looks like a solid echogenic mass. The numerous tiny cysts blend together and create a uniform solid-appearing pattern rather than visible cystic spaces. This contrasts with other CPAM types: Type I has large, clearly visible cysts; Type II has multiple small but larger-than-microcysts cysts producing a multi-cystic but still discernible pattern; Type IV presents as a single or few large peripheral cysts. So when imaging shows a solid-appearing lung mass due to microcystic components, the description fits Type III.

Type III CPAM is defined by a predominance of microscopic cysts that are too small to resolve on ultrasound, so the lesion looks like a solid echogenic mass. The numerous tiny cysts blend together and create a uniform solid-appearing pattern rather than visible cystic spaces. This contrasts with other CPAM types: Type I has large, clearly visible cysts; Type II has multiple small but larger-than-microcysts cysts producing a multi-cystic but still discernible pattern; Type IV presents as a single or few large peripheral cysts. So when imaging shows a solid-appearing lung mass due to microcystic components, the description fits Type III.