Multiple Primaries (Pre-2007)/Histology (Pre-2007)--Breast: For cases diagnosed in 2005, if a specimen contains an invasive 4.5 cm lobular carcinoma of the right breast and also has a tiny focus of intraepidermal tumors cells [Paget disease of nipple], how many cases should be abstracted and how should the histology field(s) be coded?
For tumors diagnosed prior to 2007:
There are two primaries in this example:
1. Invasive lobular carcinoma [8520/3]
2. In situ Paget disease of nipple [8540/2].
There is no combination code for lobular carcinoma and Paget disease.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
Histology (Pre-2007)--Melanoma: How is histology coded for a final pathology diagnosis of "malignant melanoma, NOS" that is clinically described as a nevus?
For tumors diagnosed prior to 2007:
Code 8720 [malignant melanoma]. Assign the histology code based on the histology stated in the final diagnosis on the pathology report. The pathology report must say melanoma arising in junctional nevus to use the code 8740/3 [Malignant melanoma in junctional nevus].
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
Reportability--Brain and CNS: Is Langerhans cell histiocytosis [9751/1] of the meninges [C709] reportable?
For cases diagnosed prior to 1/1/2010:Yes. The criteria for reportable benign/borderline CNS tumors is based on location (site) and behavior (benign/borderline). There is no caveat for histologic type. Therefore, this would be reportable as these tumors have been reported arising from the meninges or choroid plexus.
For cases diagnosed 2010 forward, refer to the Hematopoietic and Lymphoid Neoplasm Case Reportability and Coding Manual and the Hematopoietic Database (Hematopoietic DB) provided by SEER on its website to research your question. If those resources do not adequately address your issue, submit a new question to SINQ.
Histology--Breast: Does "cancerization" mean invasive for a breast tumor described as "DCIS with lobular cancerization"?
No, cancerization is not a synonym for invasive. Cells of DCIS can extend not only along the duct but also into the terminal lobules. This extension is referred to as lobular cancerization.
First Course Treatment: If an "aromatase inhibitor" used as a complement to Tamoxifen is treatment, how should it be coded?
When an aromatase inhibitor is part of the planned first course of therapy, code it under hormone treatment.
When a change of drug is PLANNED, it is part of the same course even if subcategories change. This is the usual situation with Tamoxifen and aromatase inhibitor (for example: Femara). The switch to Femara is planned, so it is not a new course. When a drug change happens that is not planned, it is still the same course if both drugs are in the same category and subcategory. An unplanned drug change to a different subcategory would be a new course.
Reportability--Skin: Is a pilomatrix carcinoma of the skin reportable if it is described as being a malignant diagnosis based on poor circumscription, infiltrative growth pattern, and focal abundant mitoses?
UPDATED June 2026
Pilomatrix carcinoma is not reportable to SEER. Skin primaries with histology codes from 8090 to 8110 are not reportable. Pilomatrix carcinoma is coded 8110/3.
See the SEER Coding Manual under Reportability, 1b: "Do not report (Exceptions to reporting requirements)"
Multiple Primaries (Pre-2007)/Histology (Pre-2007)--Brain and CNS: How many primaries should be abstracted and should the histology field(s) be coded to 9530/1 [Meningiomatosis, NOS] or 9530/0 [Meningioma, NOS] to represent a case that presents with MRI confirmed multiple meningiomas (e.g., left dura, right parasagittal region, and left frontal lobe)?
For tumors diagnosed prior to 2007:
Abstract this case as two primaries, right and left cerebral meninges. Code the histology for both primaries to 9530/0 [Meningioma, NOS]. Use code 9530/1 [Meningiomatosis, NOS] only when the diagnosis is stated to be meningiomatosis, or multiple meningiomas.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
Laterality--Breast: Should laterality be coded to 9 [Paired site but no information concerning laterality] or to the side with the positive lymph nodes for a case in which no breast mass is found but positive axillary lymph nodes are found on only one side?
Code laterality of the primary site to the side with the positive nodes when there are unilateral positive nodes and the laterality of the primary site is otherwise unknown.
Histology (Pre-2007): Is an intra-abdominal mass with the histology of "squamous cell carcinoma arising in a dermoid cyst" coded to 8070/3 [Squamous cell carcinoma] or 9084/3 [Dermoid cyst with malignant transformation]?
For tumors diagnosed prior to 2007:
Code histology to 9084/3 [Dermoid cyst with malignant transformation] per the ICD-O-3. Dermoid cysts may contain a malignant component of a type typically encountered in other organs and tissues.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.