What is the characteristic appearance associated with type 1 regression patterns in retinoblastoma?

In retinoblastoma, type 1 regression patterns are characterized by the presence of calcified masses that can resemble "cottage cheese." This appearance results from the calcification that occurs in tumor cells as they undergo necrosis and apoptosis, contributing to the specific visual texture noted in imaging and histological examinations of the retina. The calcifications are indicative of the tumor's regression process after initial growth, leading to the formation of irregularly shaped, white, calcified areas that can be quite distinctive in their presentation. This characteristic helps clinicians identify the regression pattern and assess the nature of the retinoblastoma, facilitating appropriate management strategies.