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Report Produced: 11/09/2025 16:42 PM

Report Question ID Question Discussion Answer Year
20130054 MP/H Rules/Multiple primaries--Lung: How many primaries are accessioned if a lobectomy has two tumors that are both stated to be adenocarcinoma but the pathologist states they are synchronous primaries? See Discussion.

Left upper lung lobectomy: Adenocarcinoma, poorly-differentiated (grade 3), tumor size 1.2 cm, confined to lung. Second primary lung tumor: adenocarcinoma, well-differentiated (grade 1), tumor size 0.9 cm, confined to lung. Diagnosis COMMENT: The two tumors, although both adenocarcinoma, show markedly different histologies and thus are classified as synchronous primaries. Multiple synchronous primaries are staged separately according to the 7th edition of AJCC.

The AJCC Staging Manual 7th ed states, "Multiple tumors may be considered to be synchronous primaries if they are of different histological cell types. When multiple tumors are of the same cell type, they should only be considered to be synchronous primary tumors if, in the opinion of the pathologist, based on features such as ..., they represent different subtypes of the same histologic cell type..."

In this case, the pathologist insists these are two synchronous primaries, although different subtypes are not given, because the tumors have different grades and look completely different under the microscope. The MP/H rules indicate this is a single primary. How many primaries are accessioned?

For cases diagnosed 2007 or later, accession a single primary, adenocarcinoma [8140/3] of the left upper lobe lung [C341]. The steps used to arrive at this decision are:

Open the Multiple Primary and Histology Coding Rules Manual. Choose one of the three formats (i.e., flowchart, matrix or text). Go to the Lung MP rules because site specific rules exist for this primary.

Start at the MULTIPLE TUMORS module, rule M3. The rules are intended to be reviewed in consecutive order within a module. The patient has two tumors in the same lung with the same histology.

Do not use the AJCC Manual to make multiple primary decisions. Use the MP/H Rules to determine the number of primaries to accession.

2013
20071074 MP/H Rules/Multiple Primaries--Lung: How many primaries should be reported when an "adenocarcinoma" is discovered in one of several new nodules at the scar in a lung and it is less than a year after a wedge resection for a diagnosis of "bronchioalveolar adenocarcinoma" in the same lung? See Discussion.

In March 2006 patient diagnosed with bronchioalveolar adenocarcinoma [8250/3] and had wedge resection. In November 2006 a CT chest shows nodules at the scar suspicious for recurrence. In January, 2007, there was a biopsy of one of the nodules showing adenocarcinoma [8140/3].

Is this part of the original disease process diagnosed in March 2006 or should it be abstracted as a new primary based on 2007 MP/H rules (histology is different at the first 3 digits)?

For cases diagnosed 2007 or later:

Try to obtain more information/clarification on the 2007 diagnosis -- for example, is it metastasis?

Based only on the information provided for this case, the 2007 diagnosis is a separate primary.

Use the 2007 MP/H rules to assess the 2007 diagnosis. Begin with rule M3 in the multiple tumors section. Stop at rule M11, multiple primaries.

 2007
20071051 MP/H Rules/Multiple Primaries--Lung: Please clarify the multiple primary rule M6 and the explanatory note that states when there is a single tumor in each lung, they are to be reported as multiple primaries unless stated or proven to be metastasis. See Discussion. Single tumor in left lung, single tumor in right lung. The rules take you to M6. Suppose the tumor in left lung is biopsied and there is a physician statement that right lung tumor is metastatic from left lung tumor. The note under M6 is "When there is a single tumor in each lung, abstract as multiple primaries unless stated or proven to be metastatic." In this case, is it a single primary or multiple primaries?

For cases diagnosed 2007 or later:

When there is a single tumor in one lung and a single tumor in the other lung, apply rule M6 and abstract as multiple primaries. Use this rule whenever there is a single tumor in each lung, even when neither tumor is biopsied or resected.

This rule is unique to lung. Our physician advisors emphasized that it is very unlikely that a single tumor in one lung could be metastatic from a single tumor in the opposite lung. Therefore, the default is to abstract as multiple primaries.

The note at M6 means that there must be proof that one tumor is metastatic in order to abstract as a single primary. For example, a biopsy of the tumor proving that it is metastatic. An opinion or belief that one tumor is metastatic is not sufficient. In the absence of proof, use rule M6 and abstract as multiple primaries.

A list of MP/H clarifications will be available. This issue will be included on the list.

 2007
20110130 MP/H Rules/Multiple primaries--Lung: Should a July 2011 left lower lobe mass with adenocarcinoma be accessioned as an additional primary per Rule M7 or as the same primary per Rule M12 if it is diagnosed subsequent to a September 2010 right upper lobe/right middle lobe lobectomy with clear cell adenocarcinoma in one nodule and adenocarcinoma in another nodule? See Discussion.

09/2010: RUL/RML lobectomy: Two separate nodules. One nodule showed clear cell adenocarcinoma, and the other showed adenocarcinoma (NOS). Potential brain metastasis per scan. Patient also received chemotherapy. These are two separate primaries per rule M11.

07/2011: New LLL mass + satellite nodule, biopsy of LLL mass compatible with adenocarcinoma (NOS).

Is the 07/2011 an additional new primary per rule M7? Or is it the same primary as the 09/2010 adenocarcinoma per rule M12?

For cases diagnosed 2007 or later: The 2011 diagnosis of adenocarcinoma, NOS in the left lower lobe lung is a separate primary.

The steps used to arrive at this decision are:

Open the Multiple Primary and Histology Coding Rules manual. For a lung primary, use the Lung Multiple Primary rules to determine the number of primaries.

The 2010 right lung bi-lobectomy showed two separate tumors that were determined to be two primaries: clear cell adenocarcinoma [8310/3] and adenocarcinoma, NOS [8140/3]. The histology of the new left lung mass is adenocarcinoma, NOS [8140/3].

Start at Rule M3 using the MULTIPLE TUMORS module because this patient has more than one tumor. The rules are intended to be reviewed in consecutive order within the module (i.e., from Rule M3 to Rule M12 in this case). Stop at the first rule that applies to the case you are processing. This patient has two tumors in each lung with ICD-O-3 histology codes that are different at the second (xxxx) digit. Abstract the LLL adenocarcinoma as a new primary [C343, 8140/3].

The patient has two tumors in each lung. The right lung showed adenocarcinoma and clear cell adenocarcinoma. The two tumors in the left lung were both adenocarcinomas. Clear cell adenocarcinoma [8310] on the right is different at the second digit from adenocarcinoma [8140] on the left. Rule M12 cannot be applied to this case, because Rule M7 is the first rule that applies to this case when processing the rules in consecutive order.

2011
20071040 MP/H Rules/Multiple Primaries--Melanoma: Is there a difference between multiple primary rules M6 and M7 because both rules state that tumors occurring more than 60 days apart are to be reported as multiple primaries? See Discussion.

Rule M6 clearly states that an invasive melanoma occurring more than 60 days after an in situ melanoma is a multiple primary. However M7 states that any melanomas diagnosed more than 60 days apart are multiple primaries. Since M7 does not state malignant melanomas diagnosed more than 60 days apart, this implies that any scenario:

in situ following an invasive,

invasive following an in situ,

in situ following an in situ,

or invasive following an invasive

are all multiple primaries if more than 60 days apart. If that is the intent of M7, then M6 is totally unnecessary. If the intent of M7 is only for an invasive following an invasive, then the word malignant needs to be inserted as the first word of rule M7.

For cases diagnosed 2007 or later, M7 is intended to apply to in situ and invasive melanomas. Therefore, M6 and M7 are repetitive.

This will be corrected when revisions are made to the MP/H rules. In the meantime, both M6 and M7 result in multiple primaries so it does not matter which rule is used.

 2007
20100017 MP/H Rules/Multiple primaries--Prostate: Does adenosquamous carcinoma found in the prostate represent a second primary in a patient previously diagnosed with adenocarcinoma of the prostate? See Discussion.

Patient was diagnosed many years ago with adenocarcinoma of the prostate and treated with hormonal and radiation therapy. The patient recently underwent a TURP and is found to have adenosquamous carcinoma of the prostate. The pathology report comment states squamous carcinoma of the prostate is rare and is often associated with a history of hormonal or radiation therapy. There is no information indicating a history of a squamous carcinoma in the urinary system that could have involved the prostatic urethra.

Would the MP/H rules make this a second primary with the histology of 8560/3 [adenosquamous carcinoma]?

 For cases diagnosed 2007 or later, based on the limited information available for this unusual case, abstract a second prostate primary and code the histology as adenosquamous carcinoma. Rule M3 does not apply in this case. Apply rule M10. 2010
20130221 MP/H Rules/Multiple primaries--Prostate: How many primaries are accessioned for a diagnosis of metastatic small cell neuroendocrine carcinoma of the prostate following a previous diagnosis of adenocarcinoma of the prostate? See Discussion.

Would a second prostate primary with histology coded to 8041/3 [small cell carcinoma] be accessioned for the following examples? Or are these metastases despite the different histologies?

Example 1: Prostate adenocarcinoma diagnosed in 2001, no treatment given. Metastatic small cell neuroendocrine carcinoma diagnosed 03/2012 on liver biopsy with a physician's statement in 4/2012 that the prostate is likely the cause of the metastasis to the liver.

Example 2: Prostate adenocarcinoma diagnosed in 2006, treated with TURP. Bone marrow biopsy in 5/2012 shows involvement by metastatic small cell carcinoma with morphologic and immunophenotypic features that argue against prostatic adenocarcinoma. The oncologist assessment states, "The patient has Stage 4 small cell carcinoma of the prostate and the bone marrow biopsy path shows metastatic small cell carcinoma (likely prostate in origin)."

Accession two primaries, adenocarcinoma [8140/3] of the prostate [C619], followed by small cell (neuroendocrine) carcinoma [8041/3] of the prostate [C619] for each of the examples given per Rule M10.

In each case, the second histology (because it is not adenocarcinoma) is a new prostate primary. Small cell carcinoma and small cell neuroendocrine carcinoma are not adenocarcinomas. As a result they are not covered by Rule M3.

2013
20130198 MP/H Rules/Multiple primaries--Rectosigmoid: How many primaries are accessioned for a synchronous diagnosis of neuroendocrine carcinoma and a separate adenocarcinoma arising in a villous adenoma when both arise in the rectosigmoid junction? See Discussion. Total colectomy showed neuroendocrine carcinoma of the rectosigmoid junction, as well as a separate adenocarcinoma arising in a villous adenoma of the rectosigmoid junction. Is this a single primary per Rule M13 (a frank adenocarcinoma and an adenocarcinoma in a polyp) or Rule M16 (adenocarcinoma and a more specific adenocarcinoma)? Or are these two primaries?

Accession two primaries per Rule M17, neuroendocrine carcinoma [8246/3] of the rectosigmoid junction [C199], and adenocarcinoma in a villous adenoma [8261/3] of the rectosigmoid junction [C199]. There are two tumors with ICD-O-3 histology codes that differ at the third number.

Rule M13 does not apply to neuroendocrine carcinoma. Rule M16 does not apply to this case because there are two specific histologies.

2013
20110073 MP/H Rules/Multiple primaries--Sarcoma: Does a prior clinical diagnosis of a metastatic deposit for a previously diagnosed sarcoma have priority if the diagnosis on a subsequent resection (18 months later) indicates it is also a sarcoma but does not state it represents metastasis from the original sarcoma primary? See Discussion.

1/28/08 Patient was diagnosed with spindle cell sarcoma in the right gluteus muscle. Metastatic tumors were found in a vertebral body and in the lung. Chemotherapy was started.

4/22/08 PET scan done to evaluate response to chemo. The primary tumor had increased in size. New mass in the left thigh that was highly suspicious for metastasis found. (The left thigh tumor was not accessioned at that time as it was described as a metastatic tumor.)

7/3/09 Left thigh tumor was resected and path revealed spindle cell sarcoma. There was no mention that it represented metastasis.

Does the left thigh tumor represent a new primary per rule M12? Or does the previous clinical description of the left thigh tumor representing metastasis have priority?

this is a single primary per Rule M1. According to our expert pathologist, "if multiple solid tissue tumors are present (sarcomas), then almost always there is one primary and the rest are metastases. There are infrequent occasions of multifocal liposarcoma or osteosarcoma occurring, but the patient would be treated as a patient with metastatic disease."

The steps used to arrive at this answer are:

Open the Multiple Primary and Histology Coding Rules manual. For a soft tissue primary, use one of the three formats (i.e., flowchart, matrix or text) under the Other Sites MP rules to determine the number of primaries because soft tissue primaries do not have site specific rules.

Go to the UNKNOWN IF SINGLE OR MULTIPLE TUMORS module, Rule M1.

Rule M1 states, "It is not possible to determine if there is a single tumor or multiple tumors, opt for a single tumor and abstract a single primary." Given the information from the expert pathologist, this case should be reported as a single primary applying this rule.

2011
20130165 MP/H Rules/Multiple primaries--Thyroid: How many primaries are reported and what is histology for the papillary carcinomas if a Classical cytomorphology with a follicular architecture is on the right and a Columnar cell cytomorphology with a follicular and papillary architecture is on the left? See Discussion.

  • Dominant Tumor: Tumor

  • Laterality: Right lobe

  • Tumor Size: Greatest dimension: 9 cm

  • Histologic Type: Papillary carcinoma

  • Variant, specify: Classical

  • Architecture: Follicular

  • Cytomorphology: Classical

  • Tumor Size: Greatest dimension: 6 cm

  • Histologic Type: Papillary carcinoma

  • Variant, specify: Columnar cell

  • Architecture: Solid, follicular, and papillary

  • Cytomorphology: Columnar cell

    • The answer seems to hinge on whether or not the two tumors differ at the third digit of histology. Can we code the histology based on the terms listed for variant or architecture?

    		This is a single thyroid primary. The tumors are both papillary carcinoma with follicular architecture for the most part. Apply Rule M6 and abstract a single primary. 2013