Hematopathology Reading (Articles)

Question 1

Patients presents with an anterior mediastinal mass and enlarged mediastinal lymph nodes. They are CD20+ and weakly CD30+.

Answer 1

Primary mediastinal DLBCL

A DLBCL arising from the thymus, often neighboring some residual normal thymic tissue. The architecture is often lobular with bands of fibrosis. Tumor cells are large (DLBCL large) and have oval, vesicular nuclei and one or more basophilic nucleoli. They are embedded in a sclerotic background.

This sclerotic background and large lymphoid morphology with pleomorphic, multinucleated cells can make classical nodular-sclerosing type Hodgkin lymphoma a common differential diagnosis.

Arises from the thymus, often as a bulky mass with invasion of adjacent structures. Rarely involves bone marrow or extra-mediastinal lymph nodes at the time of diagnosis.

The immunophenotype betrays that they are of thymic origin.

Question 2

Common molecular features of PMBCL and cHL

Answer 2

Both frequently have activation of the NF-kB pathway and JAK-STAT pathways, which are uncommon in DLBCL, NOS.