Primary site/Histology--Brain and CNS: How is the primary site and histology coded for a 2013 diagnosis of squamous cell carcinoma arising in a dermoid cyst of the third ventricle? See Discussion.
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.
Primary site/Heme & Lymphoid Neoplasms: How is the primary site coded if the patient presents with diffuse B cell lymphoma involving the nasopharynx and right maxillary sinus with bilateral cervical, right supraclavicular and axillary lymph nodes? See Discussion.
Primary site--Unknown & ill-defined site/Kidney: How should this field be coded when humeral metastases are compatible with renal cell carcinoma pathologically, no kidney lesion is found clinically and the physician's signout diagnosis is "no primary found, as of now unknown"? See Description.
Primary site--Testis: In the absence of a specific statement that the patient's testicle(s) are descended, should the primary site for a testicular tumor be coded as C621 (Descended Testis) when the mass is palpable on physical exam or demonstrated on scrotal ultrasound? See discussion.
Primary site--Kidney, renal pelvis: Should primary site be coded C809 [unknown] or C649 [kidney] when a patient is diagnosed with renal cell carcinoma in a transplanted kidney?
Primary site--Heme & Lymphoid Neoplasms: What the primary site for a diagnosis of Langerhans cell histiocytosis with multifocal multisystem involvement of the skin, chest, CNS and thyroid, but no evidence of involvement on a bone scan?
Primary site--Heme & Lymphoid Neoplasms: What rule applies to code a primary site for a peripheral blood diagnosis of marginal zone lymphoma that has a positive flow cytometry/FISH analysis when no biopsies are performed, scans show no evidence of disease, exam indicates no lymph nodes are palpable and the physician's clinical diagnosis "marginal zone lymphoma, unspecified site, stage 1"? See Discussion.