Emamhadi Mohammadreza, Zaresharifi Nooshin, Reihanian Zoheir, Khalili Anita, Ashoobi Mohammad Taghi, Noroozi Guilandehi Sama, Baghi Iraj, Mehrvarz Alireza
Brachial Plexus and Peripheral Nerve Injury Center, Department of Neurosurgery, Guilan University of Medical Sciences.
Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences.
Ann Med Surg (Lond). 2024 Aug 26;86(10):6241-6245. doi: 10.1097/MS9.0000000000002505. eCollection 2024 Oct.
Primitive neuro-ectodermal tumor (PNET) is a highly aggressive tumor composed of small round blue cells, mostly developing in children and young adults. Being a member of Ewing's Sarcoma Family of Tumors (ESFT); it has been discussed in two subcategories of central and peripheral PNET. PNETs of peripheral nerves are very uncommon pathologic findings, as to the best of our knowledge only 12 well-documented cases have been yet reported.
A 30-year-old male presented with progressive paresthesia of his right hand's little finger and painless swelling of the right axilla. Magnetic resonance (MR) neurography demonstrated a heterogeneous, high-signal, round mass within the right axilla fossa in proximity to the medial aspect of brachial plexus branches. The clinical and radiological study failed to an accurate diagnosis, thus surgical resection of the tumor was done for tissue evaluation. Histopathologic study of the lesion revealed a neoplasm comprising sheets of small, round, blue cells (Hematoxylin and Eosin stain), which immunohistochemically consisted with the diagnosis of PNET.
The differential diagnosis of axillary fossa masses, focusses on peripheral nerve tumors like Schwannoma and PNET. MR neurography aids in evaluation, but tissue diagnosis remains crucial. Treatment involves surgical resection, chemotherapy, and radiotherapy tailored to individual patients.
Although pPNET is not apparently the first differential diagnosis coming to mind when encountering a rapidly growing mass in the axillary fossa with peripheral nerve origin, its highly malignant behavior, makes it crucial to be considered in the differential diagnoses.
原始神经外胚层肿瘤（PNET）是一种由小圆形蓝细胞组成的高度侵袭性肿瘤，主要发生于儿童和青年。作为尤因肉瘤家族肿瘤（ESFT）的一员，它被分为中枢性和外周性PNET两个亚类进行讨论。外周神经的PNET是非常罕见的病理表现，据我们所知，仅有12例有充分记录的病例被报道。
一名30岁男性，出现右手小指进行性感觉异常和右腋窝无痛性肿胀。磁共振（MR）神经成像显示右腋窝窝内靠近臂丛神经分支内侧的一个不均匀、高信号圆形肿块。临床和影像学检查未能准确诊断，因此对肿瘤进行了手术切除以进行组织评估。病变的组织病理学研究显示肿瘤由成片的小圆形蓝细胞组成（苏木精和伊红染色），免疫组化结果符合PNET的诊断。
腋窝肿块的鉴别诊断主要集中在神经鞘瘤和PNET等周围神经肿瘤。MR神经成像有助于评估，但组织诊断仍然至关重要。治疗包括根据个体患者情况进行手术切除、化疗和放疗。
虽然在遇到起源于周围神经的腋窝快速生长肿块时，pPNET显然不是首先想到的鉴别诊断，但因其高度恶性行为，在鉴别诊断中考虑它至关重要。
