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SEER Inquiry System - Report
Produced: 09/15/2025 11:49 PM
Question 20230066
Inquiry Details
References:
#1: Solid Tumor Rules. Lung, May 2023 Update
#2: 2021 ICD-O-3.2 Update
Question:
Solid Tumor Rules/Histology--Lung: Table 3 in Lung Solid Tumor Rules, 2023 Update, lists neuroendocrine carcinoma, NOS 8246 as a specific subtype/variant for small cell carcinoma 8041/3. Should the table be updated? See Discussion.
Discussion:
Small cell carcinoma is a specific type of neuroendocrine carcinoma for the lung. However, Table 3 lists neuroendocrine carcinoma, NOS as the more specific subtype/variant in Column 3.
Using Lung Solid Tumor Rules, Rule H6, a diagnosis of poorly differentiated neuroendocrine carcinoma (small cell carcinoma)” would be coded as 8246, instead of 8041, because there are two histologies under consideration (an NOS and a subtype/variant in Table 3), and the rule tells us to code the subtype/variant. However, small cell carcinoma is more specific than the NOS diagnosis (neuroendocrine carcinoma, NOS). Should Table 3 be updated to reflect which histology is the NOS and which is the more specific?
Answer:
The Solid Tumor Rules for Lung have been updated for 2024. The row for Small cell carcinoma 8041/3 has been deleted and new separate rows have been added for Neuroendocrine carcinoma (NEC) 8246 and Neuroendocrine tumor, NOS (NET) 8240. This change is based on the WHO Classification of Thoracic Tumors, 5th edition, and current concepts. In addition, Table 3 now reflects that Small cell carcinoma/small cell neuroendocrine carcinoma 8041 (located in Column 3) is a subtype/variant of neuroendocrine carcinoma, NEC 8246 (Column 1). As a result, application of Rule H6 to a diagnosis of poorly differentiated neuroendocrine carcinoma (small cell carcinoma)” would be coded as 8041, instead of 8246. Please note: the 2024 updates may be used for cases diagnosed prior to 1/1/2024 unless otherwise noted in the rules.
