Clinicopathological analysis of 17 primary cutaneous T-cell lymphoma of the γδ phenotype from Japan

Abstract

Primary cutaneous γδ T-cell lymphoma (PCGD-TCL) is an aggressive lymphoma consisting of clonal proliferation of mature activated γδ T-cells of a cytotoxic phenotype. Because primary cutaneous γδ T-cell lymphoma is a rare disease, there are few clinicopathological studies. In addition, T-cell receptor (TCR) γδ cells are typically immunostained in frozen sections or determined by TCRβ negativity. We retrospectively analyzed 17 primary cutaneous T-cell lymphomas of the γδ phenotype (CTCL-γδ) in a clinicopathological and molecular study using paraffin-embedded sections. Among 17 patients, 11 had CTCL-γδ without subcutaneous panniculitis-like T-cell lymphoma (SPTCL) features and six had CTCL-γδ with SPTCL features. Immunophenotypically, some significant differences were found in CD8 and CD56 positivity between our patient series of CTCL-γδ patients with SPTCL features and SPTCL-γδ patients described in the previous literature. A univariate analysis of 17 CTCL-γδ patients showed that being more than 60 years old, presence of visceral organ involvement, and small-to-medium cell size were poor prognostic factors. In addition, the 5-year overall survival rate was 42.4% for the CTCL-γδ patients without SPTCL features and 80.0% for those with SPTCL features. Consequently, there was a strikingly significant difference in overall survival among SPTCL, CTCL-γδ with SPTCL features and CTCL-γδ without SPTCL features (P = 0.0005). Our data suggests that an indolent subgroup may exist in CTCL-γδ. Studies on more cases, including those from other countries, are warranted to delineate the clinicopathological features and the significance in these rare lymphomas.

Keywords: Cutaneous γδ T-cell lymphoma; T-cell receptor αβ; T-cell receptor γδ; indolent clinical behavior; subcutaneous panniculitis-like T-cell features.

Figure 1

Immunostainings of primary cutaneous T-cell lymphoma of the γδ phenotype with subcutanous panniculitis-like T-cell lymphoma (SPTCL) feature in patient no. 14 (a–l) (b–l: original magnification ×20 objective). (a) Low-power view showing subcutaneous infiltrates as in SPTCL (H&E). (b) High-power field of subcutaneous infiltrate reveals medium to large sized lymphoid cells with rimming of neoplastic cells (H&E). (c–l) Immunohistochemical results. The lymphoid cells were positive for CD3 (c), down expression of CD5 (d), negative for CD56 (e), negative for CD4 (f), positive for CD8 (g), positive for TIA-1 (h), positive for Granzyme B (i), positive for T-cell receptor (TCR) γ (j), positive for TCRδ (k) and negative for TCRβ (l).

Figure 2

Immunostainings of primary cutaneous T-cell lymphoma of the γδ phenotype without subcutanous panniculitis-like T-cell lymphoma feature in patient no. 4 (b–e: original magnification ×20 objective). (a) High-power field of cutaneous tumor reveals medium to large sized neoplastic cells infiltrating diffusely (H&E). (b–d) Immunohistochemical results. The lymphoid cells were positive for CD3 (b), positive for T-cell receptor (TCR) γ (c) and negative for TCRβ (d).

Figure 3

Immunostainings of subcutanous panniculitis-like T-cell lymphoma in patient no. 18 (a–k) (b–k: original magnification ×20 objective). (a) Low-power view of a punch biopsy. Subcutaneous infiltration of neoplastic cells are seen (H&E). (b) High-power field reveals medium to large sized atypical lymphoid cells with rimming of neoplastic cells (H&E). (c–k) Immunohistochemical results. The lymphoid cells were positive for CD3 (c), positive for CD5 (d), negative for CD56 (e), negative for CD4 (f), positive for CD8 (g), positive for TIA-1 (h), positive for Granzyme B (i), positive for T-cell receptor (TCR) β (j) and negative for TCRγ (k).

Figure 4

Overall survival of primary cutaneus T-cell lymphoma of the γδ phenotype (CTCL-γδ) without subcutaneous panniculitis-like T-cell lymphoma (SPTCL) features, CTCL-γδ with SPTCL features and SPTCL. A statistically significant difference was observed in overall survival among the SPTCL, CTCL-γδ with SPTCL features and CTCL-γδ without SPTCL features groups (P = 0.005).