Extramammary Paget’s disease (EMPD) is a rare malignant skin neoplasm characterized by intraepidermal proliferation of tumor cells. The tumor cells of EMPD may sometimes invade into the dermis or metastasize into the regional lymph nodes. Several studies have proposed mechanisms underlying the increased invasiveness of EMPD; however, molecular markers indicating invasiveness have yet to be well characterized. Laminin‐5 (Lam‐5), a heterotrimer composed of three chains (α3, β3, and γ2), is a major component of the basement membrane in many tissues. One of the chains, Lam‐5 γ2, is a marker of invasion, because it often develops as a monomer in malignant neoplasms. We investigated the expression of Lam‐5 γ2 and its role for the invasiveness in EMPD. Paraffin‐embedded specimens of EMPD obtained from 36 patients were examined immunohistochemically for Lam‐5 γ2. The cases adopted into this study comprised 16 cases of intraepidermal lesions and 20 cases with dermal invasion. The basement membrane seen in normal skin disappeared in one‐third of non‐invasive cases and in most invasive cases. The disappearance of Lam‐5 γ2 in the basement membrane and its cytoplasmic expression was more observed in the invasive cases than non‐invasive cases. Expression of Lam‐5 γ2 may be a biological marker to predict invasiveness of EMPD.

中文翻译：

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层粘连蛋白5γ2链的表达预示乳腺Paget病细胞的侵袭

乳腺Paget病（EMPD）是一种罕见的恶性皮肤肿瘤，其特征在于肿瘤细胞的表皮内增殖。EMPD的肿瘤细胞有时可能侵入真皮或转移到局部淋巴结中。一些研究提出了增加EMPD侵袭性的机制。然而，指示侵袭性的分子标记尚未得到很好的表征。Laminin-5（Lam-5）是由三条链（α3，β3和γ2）组成的异三聚体，是许多组织基底膜的主要成分。其中一条链Lam-5γ2是入侵的标志物，因为它通常在恶性肿瘤中发展为单体。我们研究了Lam-5γ2的表达及其对EMPD侵袭性的作用。对36例患者的石蜡包埋的EMPD标本进行了免疫组织化学Lam-5γ2检查。纳入本研究的病例包括16例表皮内病变和20例皮肤浸润。三分之一的非侵入性病例和大多数侵入性病例中，正常皮肤中可见的基底膜消失。在侵袭性病例中，与非侵袭性病例相比，在基底膜中Lam-5γ2的消失及其胞质表达更为明显。Lam-5γ2的表达可能是预测EMPD侵袭性的生物学标记。在侵袭性病例中，与非侵袭性病例相比，在基底膜中Lam-5γ2的消失及其胞质表达更为明显。Lam-5γ2的表达可能是预测EMPD侵袭性的生物学标记。在侵袭性病例中，与非侵袭性病例相比，在基底膜中Lam-5γ2的消失及其胞质表达更为明显。Lam-5γ2的表达可能是预测EMPD侵袭性的生物学标记。