Multiplicity Counter

Field Length:  2

This data item is optional effective with 01/01/2013 diagnoses, but remain required for diagnoses in 2007-2012.

This data item is effective with cases diagnosed January 1, 2007, and later.  It is used to count the number of tumors (multiplicity) reported as a single primary.  Use the multiple primary rules for the specific site to determine whether the tumors are a single primary or multiple primaries.

Coding Instructions

1.  Code the number of tumors being abstracted as a single primary.

2.  Do not count metastasis.

3.  When there is a tumor or tumors with separate single or multiple foci, ignore/do not count the foci.

4.  Use code 01 when:

a.  There is a single tumor in the primary site being abstracted

b.  There is a single tumor with separate foci of tumor

5.  Use code 88 for:

a.  Leukemia

b.  Lymphoma

c.  Immunoproliferative diseases

d.  Unknown primary

6.  Use code 99 when:

a.  The original pathology report is not available and the documentation does not specify whether there was a single or multiple tumors in the primary site

b.  The tumor is described as multifocal or multicentric and the number of tumors is not mentioned

c.  The tumor is described as diffuse

d.  The operative or pathology report describes multiple tumors but does not give an exact number

e.  It is unknown if there is a single tumor or multiple tumors and the multiple primary rules instructed you to default to a single tumor

7.  Leave this field blank for cases diagnosed prior to 1/1/2007.

Codes

Example 1:  The patient has a 2cm infiltrating duct carcinoma in the LIQ and a 1cm infiltrating duct carcinoma in the UIQ of the left breast.  Accession as a single primary and enter 02 in the data item Multiplicity Counter.

Example 2:  Operative report for TURB mentions multiple bladder tumors.  Pathology report: Papillary transitional cell carcinoma present in tissue from bladder neck, dome, and posterior wall.  Record 99 (multiple tumors, unknown how many) in Multiplicity Counter.

Example 3:  Pathology from colon resection shows a 3cm adenocarcinoma in the ascending colon.  Biopsy of liver shows a solitary metastatic lesion compatible with the colon primary.  Record 01 in Multiplicity Counter (do not count the metastatic lesion).

Example 4:  Patient has an excisional biopsy of the soft palate.  The pathology shows clear margins.  Record 01 in the Multiplicity Counter.  Within six months another lesion is excised from the soft palate.  Use the head and neck multiple primary rules to determine this tumor is not accessioned as a second primary.  Change the Multiplicity Counter to code 02 to reflect the fact that there were two separate tumors abstracted as a single primary.

Example 5:  CT of chest shows two lesions in the left lung and a single lesion in the right lung.  Biopsy of the right lung lesions shows adenocarcinoma.  No other workup is done.  Using the multiple primary rules for lung, the case is abstracted a single primary.  Enter the number 03 in the data item Multiplicity Counter.