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Produced: 01/07/2026 12:03 PM
Question 20130150
Inquiry Details
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Subject matter expert
Question:
MP/H Rules/Histology--Bladder: What is the histology code histology code for a bladder TUR that demonstrates mixed invasive urothelial and small cell carcinoma? See Discussion.
Discussion:
SINQ 20041104 (prior to 2007 MP/H rules) states to code histology to 8045. The MP/H rules do not address this combination of urothelial and small cell carcinoma. The current MP/H rule that applies is Rule H8, code the higher histology (8120/3). However, if the histology is coded to 8120/3, the fact that small cell carcinoma exists will be lost. If the small cell carcinoma drives the treatment plan/prognosis, shouldn't this situation be reflected in the rules for coding histology?
Answer:
Code the histology to 8045/3 [mixed small cell carcinoma]. The presence of small cell carcinoma drives the treatment decisions for this case.
This issue will be addressed in the next revision of the MP/H rules.
