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Enhanced PD‐L1 expression on tumor cells in primary cutaneous large T‐cell lymphoma with CD30 expression as classic Hodgkin lymphoma mimics: A report of lymph node lesions of two cases
Author(s) -
Takahashi Emiko,
Tsuchida Takashi,
Baba Satoshi,
Tsuzuki Toyonori,
Shimauchi Takatoshi,
Tokura Yoshiki,
Tamada Yasuhiko,
Nakamura Shigeo
Publication year - 2020
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/pin.13000
Subject(s) - cd30 , reed–sternberg cell , cd15 , lymphoma , pathology , clone (java method) , nodal , lymph node , immunohistochemistry , biology , medicine , hodgkin lymphoma , cd34 , stem cell , gene , biochemistry , genetics
Neoplastic PD‐L1 (nPD‐L1, clone SP142) expression remains unclear in cutaneous T‐cell lymphoma (CTCL), although it is well‐documented in classic Hodgkin lymphoma (CHL). Here, we report two cases of primary cutaneous large T‐cell lymphoma (PCLTCL) with CD30 expression that developed secondary nodal lesions morphologically mimicking CHL, and describe their PD‐L1 expression. Our two cases (52‐ and 60‐year‐old males) had long‐standing clinical courses of CTCL. Their PCLTCL with CD30 expression developed nodal lesions, having a nodular growth pattern containing scattered CD30+ Hodgkin and Reed‐Sternberg‐like and/or lacunar cells that expressed CD15 but did not harbor Epstein‐Barr virus. Their differential diagnosis from CHL was challenging. A diagnosis of PCLTCL with secondary nodal involvement featuring CHL mimicry was based on comparison of the primary and secondary lesions. In one case, shared expression of the same T‐cell antigen was revealed by immunohistochemistry, and in the other, identical clonal TCR rearrangement was demonstrated by polymerase chain reaction (PCR). Interestingly, nPD‐L1 was expressed on more than 50% of the tumor cells in the secondary nodal lesions, but on very few in the primary cutaneous lesions, in both cases. This is the first report of nPD‐L1 expression greatly increasing with PCLTCL tumor progression to nodal involvement.