There are specific rules for coding certain ambiguous situations:
Excision of Multiple Primaries
If multiple primaries are excised at the same time, enter the appropriate code for each site.
A total abdominal hysterectomy was performed for a patient with two primaries, one of the cervix and one of the endometrium.
Code each site as having had a total abdominal hysterectomy.
A total colectomy was performed on a patient with multiple primaries in several segments of the colon.
Code total colectomy for each of the primary segments.
Excisional Biopsy
Record an excisional biopsy as first surgical treatment, whether followed by further definitive surgery or not and whether or not residual tumor was found in a later resection. If there is no statement that the initial biopsy was excisional, yet no residual tumor was found at a later resection, assume that the biopsy was excisional.
Extranodal Lymphomas
When coding surgery for extranodal lymphomas, use the appropriate code for the extranodal site. For example, use a code for the stomach to code a lymphoma of the stomach.