Case Example 13 (Multiple Primary, Histology and Primary Site)

Seq 01 - 5/2016 Excisional bx pancreatic tail lymph node: suspicious for malignant B-cell lymphoma. No treatment recommended or administered.

Seq 02 - 2/2019 Stomach bx: MALT Lymphoma. Unknown if treatment was recommended or administered.

Involvement Comments
Lymph nodes Pancreatic tail (2016)
Organ involvement Stomach (2019)
Common metastatic sites None

Coding of the case (Lymphoma schema)

Data Item-Primary #1 Coding
M Rule M2: Single histology
PH Rule PH22: Lymph node, NOS
Per the exception found in PH22, this rule can be used due to limited information
Primary site C779: Lymph nodes, NOS
Histology 9699/3: Marginal zone lymphoma
Diagnostic confirmation 100 (single lymph node region involved)
EOD and SS state “code what you know.” We know at least one lymph node region is involved.
EOD Primary Tumor 100 (confined to lymph node region)
EOD Regional Nodes 888 (not applicable)
EOD Mets 88 (not applicable)
Summary Stage 1 (single lymph node region involved)
EOD and SS state “code what you know.” We know at least one lymph node region is involved.
Mets at Dx Data Items (all 6) Mets at Dx-Distant lymph nodes: 8, remaining Mets at Dx data items 9*

**There is no further information regarding this case, so coding unknown for the remaining mets at dx fields is correct. These can be updated if further information is found.

Data Item-Primary #2 Coding
M Rule M2: Exception
The occurrence of multiple MALT primaries is not always the same primary. Abstract multiple primaries when a nodal MALT (C770-C779, 9699/3) occurs before or after an extranodal MALT (all other sites, 9699/3). These are two distinct lymphomas that have the same histology code.
PH Rule PH24: Organ involved
Primary site C169: Stomach, NOS
Histology 9699/3: Marginal zone lymphoma
Diagnostic confirmation 1 (positive histology)
EOD Primary Tumor 200 (confined to organ)
EOD and SS state “code what you know.” We know at least the stomach is involved.
EOD Regional Nodes 888 (not applicable)
EOD Mets 88 (not applicable)
Summary Stage 1 (confined to organ)
EOD and SS state “code what you know.” We know at least the stomach is involved.
Mets at Dx Data Items (all 6) 9 (unknown)*

*There is no further information regarding this case, so coding unknown for the remaining mets at dx fields is correct. These can be updated if further information is found.

Updated: December 2, 2025