Reportability/Behavior--Kidney: Is a 2022 diagnosis of “clear cell renal cell papillary tumor” on nephrectomy reportable? See Discussion.
We are aware that the WHO 4th edition for urinary tumors has changed the behavior of “clear cell papillary renal cell carcinoma” to /1 but registries are to continue collecting as /3.
While the diagnosis in our case is stated as “tumor” it does seem like the pathologist may be using the new WHO terminology of “tumor” rather than “carcinoma,” so we are not sure if behavior is /3 or /1.
Report clear cell renal cell papillary tumor (CCRCPT), formerly classified as clear cell renal cell papillary carcinoma, and assign code 8323/3 until this new term and code (8323/1) have been adopted by standard setters.
The Kidney Solid Tumor Rules advise to code clear cell papillary renal cell carcinoma as 8323/3. WHO Classification of Tumors of the Urinary System and Male Genital Organs, 4th ed., has reclassified this histology as a /1. This change has not yet been implemented and it remains reportable.
WHO Classification of Urinary and Male Genital Tumors, 5th ed., has since reclassified clear cell papillary renal cell carcinoma as CCRCPT (8323/1). The name change was made because there have been no reports of metastatic events for this indolent tumor. The term clear cell renal cell papillary carcinoma is no longer recommended.
Solid Tumor Rules/Histology--Brain and CNS: Should the term “diffuse” be added to Note 2 in the Non-Malignant Central Nervous System (CNS) Solid Tumor Rules, Table 6: Specific Histologies, NOS, and Subtypes/Variants, for the papillary glioneuronal tumor 9509/1? See Discussion.
Should Note 2 state, "Beginning with cases diagnosed 1/1/2023 forward, diffuse leptomeningeal glioneuronal tumor is coded 9509/3? See the Malignant CNS rules." Currently the Note only states, "leptomeningeal glioneuronal tumor," but the histology that changed behavior is listed in both Table 6, Column 1 (Non-Malignant CNS) and Table 3 (Malignant CNS) as, "Diffuse leptomeningeal glioneuronal tumor."
The correct term is diffuse leptomeningeal glioneuronal tumor listed as a synonym in Column 2.
We will add the term diffuse in Note 2, Column 1 with the 2025 updates. In the meantime, you can add "diffuse" to your pdf version until the update is published.
Primary Site/Histology--Heme & Lymphoid Neoplasms: What are the correct primary site and histology for patient diagnosed with an oropharyngeal soft tissue mass revealing plasma cell neoplasm with 5-10% of marrow cellularity in 2022? See Discussion.
Patient underwent excision of an oropharyngeal soft tissue mass revealing plasma cell neoplasm with extensive amyloid deposition. During work-up, bone marrow biopsy also revealed involvement by plasma cell neoplasm, with 5-10% of marrow cellularity. No amyloid seen in bone marrow. Patient was referred for radiation of the oropharyngeal mass. Per medical oncology qualifying best for the diagnosis of solitary extramedullary plasmacytoma with minimal marrow involvement. Decision made for observation by medical oncology in view of “minimal” bone marrow involvement. Question: Is rule M11 correct, and I abstract this case as a plasma cell myeloma, 9732/3, C421?
Code as an oropharyngeal primary site and histology as solitary plasmacytoma (9734/3) based on consultation with our hematological expert.
The WHO Classification of Hematopoietic and Lymphoid Tissues defines multiple myeloma as "bone marrow plasma cell percentage >60%." There are several other factors, but the bone marrow involvement is the key point for your case. The pathologist also states that the bone marrow is consistent with "plasma cell neoplasm," which by itself is not the same as multiple myeloma.
This case has 5-10% involvement by plasma cell neoplasm. This does not meet the bone marrow qualifications for multiple myeloma and is consistent with the pathologist's statement that there is minimal bone marrow involvement.
We will be updating the Hematopoietic and Lymphoid Neoplasms Database and Manual to clarify this (2025 updates).
Reportability/Histology: Is a diagnosis of non-lung neuroendocrine tumorlet reportable? See Discussion.
Patient was diagnosed March 2023 with a neuroendocrine tumorlet of the rectum measuring 0.8 mm via excisional biopsy during colonoscopy.
Prior SINQ 20160011 (stomach specific) indicates microcarcinoid and carcinoid tumors are reportable. Microcarcinoid is a designation for neuroendocrine tumors of the stomach when they are less than 0.5 cm. in size.
Is the current rectal tumor a reportable gastrointestinal neuroendocrine tumor if it is less than 5 mm (i.e., is a neuroendocrine tumorlet equivalent to a microcarcinoid)?
Do not report neuroendocrine tumorlet of lung and non-lung sites. Microcarcinoid and carcinoid tumors are reportable.
Tumorlet is a tumor of neuroendocrine differentiation, defined by size < 5 mm in diameter, mitotic count < 2 mitoses/2 mm², and absence of necrosis. Microcarcinoid is a designation for neuroendocrine tumors when they are less than 0.5 cm. in size. The term "tumorlet" is used in a number of other settings, referring to small tumors (usually < 0.5 cm), and does not necessarily mean carcinoid tumor.
The term microcarcinoid tumor is not equivalent to neuroendocrine tumorlet.