#1: Multiple primaries
#2: Heme & Lymphoid Neoplasms
Source 1: Hematopoietic and Lymphoid Neoplasms Manual
Notes: Effective for cases diagnosed 1/1/2010 and forward
Source 2: 2018 SEER Manual
Notes: Changing Information on the Abstract
Multiple Primaries--Heme & Lymphoid Neoplasms: How many primaries are accessioned and what M rule applies when a patient is diagnosed with both plasmablastic lymphoma and at least one plasmacytoma? See Discussion.
The patient was diagnosed with an EBV-positive plasmablastic lymphoma involving the left testis on radical orchiectomy in April 2019.
In September 2019, a plasmacytoma was found on a right mandibular mass biopsy. Imaging at that time revealed diffuse disease involving the thoracic spine and sinus involvement. The patient then underwent a resection of the T8 spinal/epidural tumor that also proved plasmacytoma.
Subsequently, the right mandibular mass and testis slides were reviewed (at an outside facility) and both were stated to be,
EBV-positive plasmablastic neoplasm, best classified as plasmablastic lymphoma. The T8/epidural tumor pathology was not reviewed, so it is unclear if this is also assumed to be the same disease process as the right mandibular mass or still considered a separate, solitary plasmacytoma.
Additionally, some chart notes indicate the patient has plasmablastic lymphoma with a secondary diagnosis of plasmacytoma, while other chart notes state this is stage IV plasmablastic lymphoma involving all documented sites. Although the plasmablastic lymphoma and at least the plasmacytoma of T8 have different ICD-O-3 histology codes, the physicians do seem to be treating this as a single disease process.
Abstract multiple primaries using the Heme and Lymphoid Rule M15. The Multiple Primaries Calculator shows that the plasmablastic lymphoma (9735/3) and extraosseus plasmacytoma (9734/3) are separate primaries. We also checked with our expert pathologist who concurs as the spinal lesion was not reviewed to prove that it is plasmablastic lymphoma, therefore, the diagnosis as per pathology remains plasmacytoma.