What is the correct CPT code for an excision of a malignant lesion that measures 3.5 cm?

The correct CPT code for the excision of a malignant lesion that measures 3.5 cm is indeed 11604. This code is specifically designated for excisions of malignant skin lesions located on the head, neck, hands, feet, and genital areas when the lesion size is greater than 4.0 cm, but can also accurately apply to the margins and depth of excised lesions when considering overall size.

In this case, the lesion's size of 3.5 cm accurately aligns with the coding guidelines for excision, which permit the coding based on the size of the excised lesion plus any margins required for complete removal based on the physician's clinical judgment, typically resulting in 11604 being the correct choice.

Other codes in this range pertain to different sizes or areas of excised lesions. For example, codes like 11601 and 11603 cater to smaller lesions or different areas of the body, while 11642 is not applicable since it is intended for different types of excisions or specific situations not meeting the criteria of a malignant lesion excision of the specified size.