Fox Melanie D, Billings Steven D, Gleason Briana C, Moore Jocelyn, Thomas Antoinette B, Shea Christopher R, Victor Thomas A, Cibull Thomas L
Department of Pathology, NorthShore University HealthSystem, Evanston, IL 60201, USA.
Am J Dermatopathol. 2012 Apr;34(2):157-60. doi: 10.1097/DAD.0b013e3182286a03.
Overlapping histopathologic features of cellular neurothekeoma (CNT) and plexiform fibrohistiocytic tumor (PFHT), when both are predominantly composed of histiocytoid cells, make distinction between these entities challenging. Some have suggested that CNT and PFHT are related entities. No prior study has demonstrated a reliable immunohistochemical panel to differentiate these entities.
Skin biopsies diagnosed as CNT and PFHT, from 2004 to 2010 were retrieved with accompanying pathology reports. Each case was reviewed by at least 2 dermatopathologists and 2 soft tissue pathologists for confirmation of diagnosis. All cases were then evaluated for immunohistochemical expression of PAX2, NKIC3, CD10, and microphthalmia transcription factor (MiTF).
Histopathologically, the histiocytoid areas of each tumor shared similar architecture, demonstrating nests and fascicles of histiocytoid to spindled cells, with some separation of nests by collagen bands. Both CNT and PFHT were uniformly positive for NKIC3 and CD10, and both were frequently PAX2 positive. MiTF was strongly and diffusely positive in CNT and was consistently negative in the PFHT.
CNT and PFHT share many histopathologic features and immunohistochemical staining patterns. Of the stains we evaluated, we found that expression of MiTF may be a reliable marker for distinguishing CNT from histiocytoid-predominant PFHT, especially in instances where only a small part of the tumor is sampled for evaluation.
当细胞性神经鞘瘤（CNT）和丛状纤维组织细胞瘤（PFHT）主要由组织细胞样细胞组成时，它们重叠的组织病理学特征使得区分这两种实体具有挑战性。一些人认为CNT和PFHT是相关实体。此前尚无研究证明有可靠的免疫组化指标可区分这两种实体。
检索2004年至2010年诊断为CNT和PFHT的皮肤活检标本及相关病理报告。每个病例至少由2名皮肤病理学家和2名软组织病理学家复查以确诊。然后对所有病例评估PAX2、NKIC3、CD10和小眼转录因子（MiTF）的免疫组化表达情况。
在组织病理学上，每个肿瘤的组织细胞样区域具有相似的结构，显示出组织细胞样至梭形细胞的巢状和束状结构，巢之间有一些胶原带分隔。CNT和PFHT的NKIC3和CD10均呈一致阳性，且两者均常为PAX2阳性。MiTF在CNT中呈强弥漫性阳性，在PFHT中始终为阴性。
CNT和PFHT具有许多组织病理学特征和免疫组化染色模式。在我们评估的染色指标中，发现MiTF的表达可能是区分CNT和以组织细胞样为主的PFHT的可靠标志物，尤其是在仅取肿瘤一小部分进行评估的情况下。
