MP/H Rules/Histology--Lung: What is the correct histology code for an initial biopsy of non-small cell carcinoma with neuroendocrine phenotype, possible large cell neuroendocrine carcinoma with a subsequent re-biopsy showing poorly differentiated small cell carcinoma after chemotherapy with no response? See discussion.
Update to current manual/Solid Tumor Rules (2018)/Histology--Lung: What is the histology code and what M Rule applies when there are multiple specific subtypes identified using various equivalent lung terms but only one is stated to be predominant? See Discussion.
MP/H Rules/Histology--Breast: What histology code and MP/H Rule applies to the Histologic Type of "invasive ductal carcinoma with metaplastic stroma" for a single breast tumor? See Discussion.
Histology (Pre-2007)--Breast: What code is used to represent the histology "Ductal carcinoma in situ; 6 mm focus of invasion is a pure mucinous carcinoma that appears to have arisen in the background of encysted papillary carcinoma."
Solid Tumor Rules/Histology--Thyroid: What is the correct histology code for a papillary carcinoma, encapsulated with columnar cell features? See Discussion.
Primary Site--Heme & Lymphoid Neoplasms: What primary site code should be assigned and what rule justifies that code?
Scenario: Pleural effusion, underwent thoracentesis. Pleural fluid unexpectedly showed Large B-Cell Lymphoma. Extensive workup including CT & PET was done and all findings were within normal limits. No evidence of lymphoma was seen and no palpable adenopathy was found. The only indication of lymphoma was the malignant pleural effusion.
Solid Tumor Rules/Histology--Thyroid: What is the histology code for a diagnosis of poorly differentiated thyroid carcinoma arising in a background of solid papillary thyroid carcinoma? See Discussion.