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SEER Inquiry System - Report
Produced: 03/13/2026 1:10 PM
Question 20180088
Inquiry Details
References:
Solid Tumor Rules. Other Sites, updated 9/11/2018
Question:
Solid Tumor Rules (2018)/Multiple primaries--Prostate: How many primaries are abstracted and what M Rule applies when a patient is diagnosed with prostate adenocarcinoma in 2014, followed by liver mass biopsy showing neuroendocrine carcinoma, small cell type of the prostate in 2018? See Discussion.
Discussion:
The patient has a history of prostate adenocarcinoma with lymph node metastases, status post prostatectomy and treatment by Lupron in 2014. The most recent prostate serum antigen measurement (April 2018) was normal. CT scan of the abdomen and pelvis revealed new hypodense liver lesions, a slightly enlarging lung right lower lobe nodule, and enlarging lobular mass in the prostatectomy bed. The core liver biopsy contains areas of metastatic tumor with a differential diagnosis on pathology of high-grade neuroendocrine carcinoma of the prostate (small cell type), which may have been seen in association with prostate adenocarcinoma, or metastatic small cell carcinoma of a different site.
Clinically, the physician impression is that this represents metastatic castration-resistant prostate cancer. The Solid Tumor Rules note that the Multiple Primary Rules are not used for tumor(s) described as metastases. However, SINQ 20130221 indicates that, at least historically, these would have been accessioned as multiple primaries (histology 8140 & 8041 per Rule M10). Does the previous SINQ note still apply to these types of cases, and if so how would one know to move beyond the initial note indicating metastases are not new primaries?
Answer:
The guidance provided in SINQ 20130221 still applies. Accession two primaries, adenocarcinoma [8140/3] of the prostate [C619], followed by small cell (neuroendocrine) carcinoma [8041/3] of the prostate [C619] for each of the examples given per Rule M10 of the 2018 Solid Tumor Rules, Prostate. In each case, the second histology (because it is not adenocarcinoma) is a new prostate primary. Small cell carcinoma and small cell neuroendocrine carcinoma are not adenocarcinomas. As a result, they are not covered by Rule M3.
For the case described in this SINQ submission, based on the findings of a lobular mass in the prostate bed, this is a second primary (there is residual prostatic tissue).
This is unchanged from the 2007 Multiple Primaries Rules for Other Sites.
