MP/H Rules/Histology--Head and Neck: What is the histology code for salivary duct carcinoma of parotid gland?
Code salivary duct carcinoma to invasive ductal carcinoma (8500/3). Salivary duct carcinoma is an aggressive adenocarcinoma which resembles high-grade breast ductal carcinoma according to the WHO Classification of Tumors of Head & Neck.
Reportability--Appendix: Is the appendix the primary site for a low grade mucinous appendiceal neoplasm (LAMN) with diffuse peritoneal dissemination? See discussion.
Patient had an appendectomy revealing a low grade mucinous appendiceal neoplasm (LAMN) with diffuse peritoneal dissemination. Patient now with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC), which revealed metastatic disease in the abdomen, omentum, pelvic peritoneum, peri-cecal, and gallbladder.
For cases diagnosed prior to 1/1/2022
Low-grade appendiceal mucinous neoplasm (LAMN) is not reportable, even when it spreads within the peritoneal cavity, according to our expert pathologist consultant. Peritoneal spread of this /1 neoplasm does not indicate malignancy. It is still /1 when there is spread of LAMN in the peritoneal cavity.
MP/H Rules/Histology--Skin: How is histology coded for an "endocrine mucin-producing sweat gland carcinoma with transformation to mucinous carcinoma"? See Discussion.
Endocrine mucin-producing sweat gland carcinoma (EMPSCG) is a rare type of low-grade sweat gland carcinoma. Some journal articles indicate that most patients with EMPSCG have coexisting mucinous carcinomas, suggesting that EMPSCG is a precursor to invasive mucinous carcinoma of the skin. Sweat gland carcinoma has its own histology code per the ICD-O-3 (8400/3); should an endocrine mucin-producing sweat gland carcinoma also be coded as 8400/3? If so, would the correct histology for the skin case above be mucinous carcinoma (8480/3) per Rule H17? Conversely, if the terms "mucin-producing" are referring to mucin-producing carcinoma, and not referring to the sweat gland carcinoma, would the histology be coded 8481/3 (mucin-producing carcinoma)?
Assign 8480/3.
There is no mixed ICD-O-3 code for EMPSCG. Both histologies are in the mucinous family: mucinous adenocarcinoma (8480/3) and sweat gland carcinoma (8400/3). Apply Other sites rule H17 and code the numerically higher ICD-O-3 code (8480/3).
Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare low-grade sweat gland carcinoma with a strong predilection to the eyelid region. It is histologically analogous to endocrine ductal carcinoma/solid papillary carcinoma of the breast and is characterized by a multinodular solid cystic mucinous tumor with immunoreactivity to neuroendocrine markers. Only 20 cases of this unusual tumor have been reported.
MP/H Rules/Multiple Primaries: Is this counted as one or two primaries?
Patient is diagnosed with SCC esophageal cancer. Work-up reveals a lung nodule. Lung FNA (cytology) is read by the pathologist as SCC, favor metastatic esophageal SCC. However, the managing physicians are treating the patient as two separate primaries.
If the patient is being managed and treated as a case of primary lung cancer, report the lung diagnosis as a separate primary.
Reportability/Histology: Would a histology reading "Well-differentiated neuroendocrine neoplasm" of the appendix be reportable? Since the word "tumor NOS" and "neoplasm NOS" both code to 8000, I would assume they would be interchangeable but just wanted to verify.
According to SINQ 20130027 & 20140002 a "Well-differentiated neuroendocrine tumor" of the appendix IS reportable.
"Well-differentiated neuroendocrine neoplasm" of the appendix is reportable. According to the WHO classification of Digestive System Tumors, "Well-differentiated neuroendocrine neoplasm" of the appendix is synonymous with NET. WHO states on page 13 "The term 'neuroendocrine neoplasm' can be used synonymously with 'neuroendocrine tumor.'"
Neuroendocrine "tumor," or NET G1, is listed in the WHO classification as one of the malignant neoplasms of the appendix.
MP/H Rules/Multiple primaries--Breast: Does rule M10 apply in this situation?
L breast biopsy = INVASIVE DUCTAL CARCINOMA
L breast simple mastectomy = 2.0 cm INVASIVE DUCTAL CARCINOMA with an incidental finding of separate 1.0 cm INVASIVE LOBULAR CARCINOMA; pathologist specifically states the tumors are morphologically different. The tumors are both pure Ductal/pure Lobular.
Yes, Breast rule M10 applies. This case is a single primary.
Follow the MP/H rules even though the "pathologist specifically states the tumors are morphologically different" so that situations like this are reported consistenty accross cancer registries, regions, and states for consistent national reporting.
MP/H Rules/Multiple primaries--Colon: This is an unusual case of multifocal colon cancer. The case is staged pT4b,N1b. Per our MP rules, this will be 4 separate primaries. Would this be an exception to the rules; if not now, possibly in future versions of the MP rules for colon cancer? See discussion.
The path report reads: COMMENT: There is multifocal involvement throughout both bowel segments which combined represent a subtotal colectomy procedure. There are at least 11 tumors, all of which are histologically similar. Given the unusual gross appearance, a representative portion of the largest mass (hepatic flexure) was forwarded to _____ for flow cytometric evaluation. There is chronic active colitis in the background suggestive of idiopathic inflammatory bowel disease, specifically ulcerative colitis. However, no dysplasia is seen in multiple random sections of grossly benign large bowel. ADDENDUM from expert gastroenterologist: The carcinomas are poorly differentiated without specific histologic features but are consistent with colon primaries. These findings are consistent with an MLH1-deficient carcinoma. Given the background chronic active colitis consistent with ulcerative colitis, this likely represents colitis-associated neoplasia which can be associated with multifocality.
This unusual case of multifocal colon cancer is not an exception to the MP/H rules currently.
The current WHO classification for colon tumors mentions ulcerative colitis (UC) associated colorectal cancers and states they are often multiple. This will be discussed for the next version of the MP/H rules.
Seq no-central--Brain and CNS: How should subsequent tumors be sequenced when the patient has a history of a brain tumor, with no information on the behavior of the brain tumor? According to the sequencing rules, it appears some assumption must be made regarding the behavior of the brain tumor.
Sequence the brain tumor in the 60-87 series when you do not know the behavior. If you have reason to believe the brain tumor was malignant, sequence it in the 00-59 series.
Reportability--Brain and CNS: Is schwannoma of the extracranial part of a cranial nerve reportable? Some cranial nerves, like facial nerve, have intracranial and extracranial branches.
An extracranial schwannoma is not reportable. The schwannoma must arise on the intracranial part of the nerve to be reportable.