#dermpathJC October 2020 summary

#dermpathJC October 2020:

Thursday, October 29th, 9pm EST

Article Discussed: A review of CD30 expression in cutaneous neoplasms

Authors: Drs. Franziska Kampa and Christina Mitteldorf

Temporary free access courtesy of Journal of Cutaneous Pathology, link: https://onlinelibrary.wiley.com/doi/abs/10.1111/cup.13894

Summary prepared by: Maryam Aghighi, MD (@maryam_aghighi)

Editor: Silvija P. Gottesman, MD (@SGottesmanMD)

Journal Club Summary:

The current article reviewed the literature for CD30 expression in lymphoproliferative disorders and solid tumors of the skin.
CD30 (Ki-1) is a transmembrane protein in the tumor necrosis factor receptor superfamily. It is expressed by Reed-Steinberg cells. The CD30 ligand (cytokine) is detected on activated lymphocytes, histiocytes and granulocytes.
CD30 is expressed mainly on Th2 cells, but there is some published data that Th0 and Th1 cells show CD30 expression. As for B-cells, CD30 is expressed in B-cell immunoblasts, found at the germinal center periphery.
CD30 is expressed in anaplastic large cell lymphoma (ALCL), Hodgkin lymphoma (HL), lymphomatoid papulosis (LyP), mycosis fungoides (MF), follicle center cell lymphoma (FCL) and Epstein-Barr virus (EBV)-associated lymphomas.
Brentuximab vedotin (BV) is an anti-CD30 monoclonal antibody, conjugated with monomethylauristatin, and used in the treatment of CD30+ HL, systemic ALCL, CD30 expressing peripheral T-cell lymphomas and CD30+ cutaneous T-cell lymphomas.
Treatment with BV has been effective in cutaneous T-cell lymphomas (CTCL) and diffuse large B-cell lymphoma (DLBCL) including in cases with low or absent CD30 expression.
In cutaneous lymphomas, the CD30 positivity threshold is under debate. Up to 40% of hematopathologists use a positive cut-off value of >20% CD30+ cells, while the response cutoff in BV clinical trials was >10% CD30+.
Cutaneous and folliculotropic MF patients with a higher dermal CD30 expression showed a more advanced stage at diagnosis, higher maximum stage, lower survival rate and poor prognosis. However, patients with high epidermal CD30 expression revealed higher survival rate.
Transformed MF (T-MF) is diagnosed if >25% large cells (>4x the size of a lymphocyte) are present. Dermal CD30 expression is related to a better prognosis in T-MF and absence of CD30 expression was associated with poorer prognosis. Interestingly, higher epidermal CD30 expression compared to dermal CD30 expression was associated with a poorer survival.
In other rare types of CTCLs, published literature to date of CD30 expression is as follows:
- In pagetoid reticulosis (PR), more than 50% of the tumor cells were CD30+.
- Primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS) reported CD30 expression as follows:
  - One study showed low expression of CD30 (<5%) in most of their patients.
  - One study showed more than half the studied patients to have a CD30 expression of 25% or more.
  - In small-medium pleomorphic T-cell lymphoma (SMPTCL) CD30-positive expression was reported between <1% and 30%.
- In cases of extranodal NK/T-cell-lymphoma (ENK/TCL), CD30 positivity has been seen and in one case reaching >80%.
- Primary cutaneous gamma-delta T-cell lymphoma (pcGD-TCL), primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma (pcAECTCL) and subcutaneous panniculitis-like T-cell Lymphoma (SPTL) reported CD30 expression (further reading recommended to explore the amount of CD30 expression in each of these distinct entities).
- A single case of primary cutaneous acral CD8+ T-cell lymphoma (pcATCL) reported negative CD30 expression.
- Adult T-cell leukemia/lymphoma (ATLL) reported positive CD30 expression but skin expression of CD30 positivity was not mentioned.
Observed CD30 expression in primary cutaneous B-cell lymphomas is as follows:
- Primary cutaneous follicle center B-cell lymphomas with CD30 expression was seen in few patients and primary cutaneous marginal zone B-cell lymphoma showing CD30 positivity was seen in even fewer patients.
- Four diffuse large B-cell lymphoma leg type patients reported negative CD30 staining.
EDV-positive mucocutaneous ulcer and EDV-associated lymphoproliferative disorders reported high CD30 expression.
Blastic plasmacytoid dendritic cell neoplasm – negative CD30 expression reported thus far.
Cutaneous mastocytosis had CD30 expression in 96.5% of cases (29 study patients).
Other notable neoplasms that also showed expression of CD30 were lymphadenomas. CD30 expression was reported in the the tumor microenvironment (TME) of BCC, SCC and keratoacanthomas.
There was no data reported regarding CD30 expression in Merkel cell carcinoma and only a couple of cases of atypical fibroxanthoma with reported CD30 expression.