Histology (Pre-2007): Can the histology code 8582/3, "thymoma, mixed type, malignant" only be used when you have a thymoma with both type A and type B features? See discussion.
Histology (Pre-2007): Can we ever code this field using a more specific cell type from a metastatic site specimen rather than to a less specific cell type from the primary site specimen? See Discussion.
Histology (Pre-2007): Do the terms "keratinizing" or "non-keratinizing" have to be present in the final diagnosis to use codes 8071 through 8073? See discussion.
Histology (Pre-2007): How are the following four histologies coded: 1) Adenocarcinoma with focal mucinous adenocarcinoma; 2) Adenocarcinoma with focal areas of bronchioalveolar adenocarcinoma, 3) Mixed infiltrating duct and focal medullary carcinoma, and 4) Mixed infiltrating duct and focal medullary carcinoma? See Description.
Histology (Pre-2007): Is 8524 [lobular mixed with other carcinoma] or 8490 [signet ring cell carcinoma] used to represent a diagnosis of "infiltrating lobular with signet ring features?"
Histology (Pre-2007): Is a small cell undifferentiated carcinoma coded to 8041/34 [small cell carcinoma undifferentiated] or to 8045/34 [combination small cell AND undifferentiated carcinoma] using terms from the 2 columns in Appendix 1 of Coding Complex Morphologic Diagnoses? See discussion.
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]?
Histology (Pre-2007): Is histology for an anorectal biopsy of "Cloacogenic carcinoma (squamous cell carcinoma with basaloid features)" coded to 8124/3 [Cloacogenic carcinoma] or 8083/3 [Basaloid squamous cell carcinoma]?
Histology (Pre-2007): What code is best used to represent a diagnosis of "metaplastic carcinoma, matrix producing type." The tumor shows poorly differentiated infiltrating duct carcinoma and myxoid, cartilaginous stroma.