SEER Inquiry System - View
Source 1: 2007 MP/H Rules
MP/H Rules/Multiple primaries--Head & Neck: How many primaries are accessioned and what rule applies if a patient has an extensive tumor in the left ethmoid sinus and a separate tumor in the right maxillary sinus?
MRI and CT Neck Impression: Extensive tumor mass which likely originated within the left ethmoid sinus and extends intracranially via the cribriform plate into the anterior cranial fossa. There is involvement of the left orbit and extension into the superior aspect of the left maxillary sinuses as well as the nose. Second enhancing lesion within the right maxillary sinus measures almost 2 cm. The second mass within the floor of the right maxillary sinus, with similar imaging characteristics, is consistent with malignant involvement.
The patient has an extensive ethmoid sinus tumor, biopsy showed squamous cell carcinoma. The ethmoid sinus is not a paired organ. The patient also has a small maxillary tumor with no histologic confirmation, Hem/Oncology chart notes state the right maxillary sinus mass is carcinoma. The maxillary sinus is a paired organ.
Per the AJCC Manual (AJCC Manual for Staging, 7th edition, page 70), both the ethmoid and maxillary sinuses are further identified by their laterality (left and right). Why arenít the ethmoid sinuses considered a paired organ for the MP/H Rules? What MP rule applies to this case?
For cases diagnosed 2007-2014, accession a single primary. The steps used to arrive at this decision are:
Step 1: Open the Multiple Primary and Histology Coding Rules Manual. Choose one of the three formats (i.e., flowchart, matrix or text). Go to the Head and Neck MP rules after determining the histology of each tumor - (8070/3 [squamous cell carcinoma] and 8010/3 [carcinoma, NOS]) because site specific rules have been developed for this primary.
Step 2: Start at the MULTIPLE TUMORS module, Rule M3. The rules are intended to be reviewed in consecutive order within a module. Abstract a single when one tumor is carcinoma, NOS  and another tumor is a specific carcinoma, squamous cell carcinoma  because the ethmoid sinus (site of origin) is not considered a paired site per the MP/H rules. Stop at Rule M10.
We will review the list of paired organs for the next edition of the MP/H Rules.