Val-Bernal José Fernando, Cagigal María Luisa, Mazorra Remigio
Department of Medical and Surgical Sciences, University of Cantabria, Santander, Spain;
Rom J Morphol Embryol. 2018;59(1):385-390.
The plexiform variant of spindle cell lipoma is very uncommon. In fact, as far as we are aware only seven cases have been previously reported. We describe herein the case of a 49-year-old man with a smooth nodule of the mucosa of the lower lip that was gradually increasing. Surgical excision of the lesion was done and the study revealed the histological and immunohistochemical features of a plexiform spindle cell lipoma (PSCL). Peculiar to this case was the location in the lip, the presence of abundant S100-positive dendritic cells, and scarce mature lipogenic cells. S100 protein reactivity has rarely been observed in classical and plexiform spindle cell lipoma. To our knowledge, no case of PSCL displaying abundant S100-positive dendritic cells has been described. This feature may lead to a diagnostic pitfall. The main differential diagnosis includes the neuroma group, plexiform intraneural neurofibroma (PIN), plexiform schwannoma and plexiform hybrid tumor of perineurioma and cellular neurothekeoma. It is imperative correctly diagnose and differentiate PSCL from neural tumors because they may show syndromic associations, have different prognosis, including malignant transformation in PIN, and the management of all these lesions differs.
梭形细胞脂肪瘤的丛状变型非常罕见。事实上，据我们所知，此前仅报道过7例。我们在此描述一例49岁男性病例，其下唇黏膜有一个逐渐增大的光滑结节。对该病变进行了手术切除，研究显示其具有丛状梭形细胞脂肪瘤（PSCL）的组织学和免疫组化特征。该病例的独特之处在于其位于唇部，存在大量S100阳性树突状细胞，且成熟脂肪生成细胞稀少。在经典型和丛状梭形细胞脂肪瘤中很少观察到S100蛋白反应性。据我们所知，尚未有显示大量S100阳性树突状细胞的PSCL病例被描述。这一特征可能导致诊断陷阱。主要鉴别诊断包括神经瘤组、丛状神经内神经纤维瘤（PIN）、丛状神经鞘瘤以及神经束膜瘤和细胞性神经鞘瘤的丛状混合瘤。正确诊断并将PSCL与神经肿瘤区分开来至关重要，因为它们可能显示综合征关联，具有不同的预后，包括PIN的恶性转化，并且所有这些病变的处理方式也不同。
