Case Example 1 (Primary Site and Histology)

  • CT scan 10/25: Marked abdominal and retroperitoneal lymphadenopathy, findings concerning for lymphoma. MRI abdomen on 10/25: Persistent abdominal adenopathy concerning for lymphoproliferative disease. Left neck lymph node bx neg on 10/25.
  • CT abdomen & pelvis on 11/25: New and enlarging lung nodules suspicious for metastatic disease. Worsening abdominal adenopathy.
  • CT chest on 12/25: Significant progression of multifocal pulmonary nodules, both increased in size and number, highly concerning for metastatic disease. There is marked mediastinal and hilar lymphadenopathy. Marked retroperitoneal and periportal lymphadenopathy is similar to the prior CT/MRI.
  • Lymph node, perigastric, FNA on 1/26 and duodenum lesion bx on 1/26: diffuse large B-cell lymphoma.
Involvement Comments
Lymph nodes Abdominal and retroperitoneal lymphadenopathy
Mediastinal and hilar lymphadenopathy
Perigastric (confirmed by bx)
Organ involvement Duodenum (confirmed by bx)
The perigastric lymph nodes, which are regional for stomach, include the pyloric nodes, which are regional for the duodenum
Common metastatic sites Lung

Coding of the case (Lymphoma schema)

Data Item Coding
M Rule M2: Single histology
PH Rule PH25: Organ with regional lymph nodes
The stomach and the pyloric nodes are involved. The remaining lymph nodes are recorded in Mets at Dx-Distant lymph nodes
Primary site C170: Duodenum
Histology 9680/3: Diffuse large B-cell lymphoma
Diagnostic confirmation 1 (histology only)
EOD Primary Tumor 800 (due to lung involvement, distant lymph nodes)
EOD Regional Nodes 888 (not applicable)
EOD Mets 88 (not applicable)
Summary Stage 7 (distant due to lung involvement, distant lymph nodes)
Mets at Dx Bone 0 (no involvement)
Mets at Dx Brain 0 (no involvement)
Mets at Dx Liver 0 (no involvement)
Mets at Dx Lung 1 (involvement)
Mets at Dx Distant Lymph Nodes 1 (involvement)
Mets at Dx Other 0 (no involvement)

Updated: December 2, 2025