Lenartowicz Karina A, Amrami Kimberly K, Torres-Mora Jorge, Spinner Robert J
1Mayo Clinic Alix School of Medicine, Mayo Clinic, Rochester, Minnesota; and.
Departments of2Radiology.
J Neurosurg Case Lessons. 2023 Apr 10;5(15). doi: 10.3171/CASE23112.
Perineuriomas are peripheral nerve sheath tumors that are composed of benign, localized proliferations of perineural cells and further subclassified as intraneural or extraneural (soft tissue) based on their relationship to the histological boundaries of the nerve. Multiple histological variants have been described, and herein the authors present the first known case of a pseudolipoblastic perineurioma affecting the nerve.
A 52-year-old woman presented with a 5-year history of progressive, severe left buttock pain radiating down to the top of her foot and ankle, without any associated weakness, with a large mass in her sciatic nerve noted on magnetic resonance imaging (MRI). She underwent resection, which demonstrated a pseudolipoblastic perineurioma of the sciatic nerve, an unusual histological subtype composed of perineurial cells with an abundant clear intracytoplasmic background. Postoperatively, her pain resolved, and follow-up MRI showed no tumor persistence or recurrence.
On imaging, this lesion had a benign appearance, with areas suggestive of subacute hemorrhage, and was associated with a nerve. Although the distinctive morphological features of this lesion may suggest liposarcoma, careful morphological evaluation and appropriate immunohistochemical studies allow its correct classification.
神经束膜瘤是由神经束膜细胞的良性局限性增生构成的周围神经鞘瘤，根据其与神经组织学边界的关系可进一步分为神经内型或神经外型（软组织型）。已描述了多种组织学变异型，本文作者报告了首例累及神经的假脂肪母细胞性神经束膜瘤病例。
一名52岁女性，有5年进行性严重左臀部疼痛病史，疼痛向下放射至足尖和踝部，无任何相关无力症状，磁共振成像（MRI）显示坐骨神经有一巨大肿块。她接受了手术切除，病理显示为坐骨神经假脂肪母细胞性神经束膜瘤，这是一种不寻常的组织学亚型，由具有丰富透明胞浆背景的神经束膜细胞组成。术后，她的疼痛缓解，随访MRI显示无肿瘤残留或复发。
在影像学上，该病变表现为良性，有提示亚急性出血的区域，且与神经相关。尽管该病变独特的形态特征可能提示脂肪肉瘤，但仔细的形态学评估和适当的免疫组化研究可实现其正确分类。
