Histology (Pre-2007): What code is used to represent the histology if the final diagnosis between an electron microscopy report and the immunocytochemistry (ICC) differs and both histologies are specific (e.g., one report states papillary carcinoma and the other states squamous cell carcinoma)?
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?
Histology (Pre-2007)--Colon: Must a case be specifically labeled "familial adenomatous polyposis" or is the mere presence of numerous/multiple polyps sufficient for coding the histology to FAP?
Histology (Pre-2007)--Lung: Should the histology "Polymorphic Adenocarcinoma" be coded to 8022/33 [Polymorphic Carcinoma] or 8140/33 [Adenocarcinoma, NOS]?
Primary Site/Histology (Pre-2007)--Mediastinum: How do we code these fields for a case described as a "neuroendocrine carcinoma" of the "anterior mediastinum" without failing the SEER "impossible" site/histology combination edit? See Discussion.
Histology (Pre-2007)--Breast: Should the histology "non-invasive papillary carcinoma" along with the comment "solid intraductal papillary proliferation includes cytologically atypical cells with scattered mitotic figures" be coded to 8503/2 [intraductal papillary carcinoma] or 8050/2 [papillary carcinoma in situ]?
Histology (Pre-2007)--Ovary: Should the histology "endometroid adenocarcinoma arising in a serous fibroadenoma" be coded to 8380 [Endometroid adenocarcinoma, NOS] or 9014 [Malignant serous fibroadenoma]?
Primary site/Histology (Pre-2007)/Behavior: What is the correct site and histology/behavior for the following diagnosis: "mucinous cystadenoma of the appendix with perforation and pseudomyxoma peritonei." This was diagnosed at e-lap for a separate adenocarcinoma of the ascending colon.