The Spine Journal 15 (2015) 205–206
Plexiform schwannoma arising from cauda equina A 61-year-old woman with rheumatoid arthritis (RA) presented with unprecedented progressive low back and bilateral lower leg dull-pain. She has a 10-year and 7year history of methotrexate and etanercept treatment for RA, respectively. Physical examination revealed the absence of neurologic compromise. There was no evidence of any skin pigmentation and familial history of neurogenic tumors. Plain radiographs of the lumbar spine revealed degenerative changes, especially at L2/L3 level (Fig. 1). The plain magnetic resonance imaging (MRI) revealed intradural low-intensity lesion on both T1- and T2-weighted images (Fig. 2, Left and Middle); however, which may have been overlooked without gadoliniumenhanced MRI (Gd-MRI). The succeeding Gd-MRI of lumbar spine clearly revealed a homogeneously enhanced intradural lesion that extended from L2 to L4 (Fig. 2, Right). Computed tomography revealed neither calcification of the lesion nor bone scalloping (data not shown). Taking all these findings including being under treatment
using methotrexate and etanercept for the treatment of RA into consideration, a malignant tumor such as malignant lymphoma was first considered as a differential diagnosis. Other radiologic differential diagnosis of the lesion includes schwannoma, meningioma, and so on. We conducted excisional biopsy of the lesion. After laminectomy from L2 to L4, dural sac was opened at midline and intradural plexiform tumor was found. En block total extirpation was successfully performed (Fig. 3, A and B). Histologic examination revealed spindle-shaped cells arranged in short bundles with foci of nuclear palisading (Fig. 3, C). Diffuse and constant expression for S-100 protein was confirmed (Fig. 3, D). Neither nuclear atypia nor mitotic figures were observed. These findings were consistent with benign plexiform schwannoma. The improvement of preoperative symptoms was confirmed soon after the operation. At the time of the latest follow-up, 1 year after the surgery, the patient was free of symptom without evidence of re-growth of the lesion. Spinal plexiform schwannoma is extremely rare and, to the best of our knowledge, only two such cases have been reported [1,2]. This is the first case of plexiform schwannoma arising at cauda equina.
Fig. 1. Plain radiographs of the lumbar spine revealed degenerative changes, especially at L2-3 level. http://dx.doi.org/10.1016/j.spinee.2014.09.005 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
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K. Mori et al. / The Spine Journal 15 (2015) 205–206
Fig. 2. (Left) T1- and (Middle) T2-weighted preoperative magnetic resonance imaging (MRI) showing intradural low-intensity lesion. (Right) Gadoliniumenhanced MRI clearly revealed a homogeneously enhanced intradural lesion that extended from L2 to L4. Arrows indicates the level of axial views.
References [1] Sakaura H, Ohshima K, Iwasaki M, Yoshikawa H. Intra-extradural plexiform schwannoma of the cervical spine. Spine 2007;32:E611–4. [2] Capone F, Pravata E, Novello M, Moncelsi S, Pirronti T, Meglio M, et al. A rare case of life-threatening giant plexiform schwannoma. Spine J 2012;12:83.
Kanji Mori, MD, PhDa Shinji Imai, MD, PhDa Kazuya Nishizawa, MD, PhDa Akira Nakamura, MDa Mitsuaki Ishida, MD, PhDb Yoshitaka Matsusue, MD, PhDa a Department of Orthopaedic Surgery Shiga University of Medical Science
Tsukinowa-cho, Seta, Otsu Shiga, 520-2192, Japan b Department of Clinical Laboratory Medicine Shiga University of Medical Science Tsukinowa-cho, Seta, Otsu Shiga, 520-2192, Japan FDA device/drug status: Not applicable. Author disclosures: KM: Nothing to disclose. SI: Nothing to disclose. KN: Nothing to disclose. AN: Nothing to disclose. MI: Nothing to disclose. YM: Nothing to disclose.
Fig. 3. (A and B) Macroscopic findings of the tumor showed yellowish, well-circumscribed, and multilobulated lesion. (C) Histologic examination revealed spindle-shaped cells arranged in short bundles with foci of nuclear palisading (hematoxylin and eosin, original magnification, 100), (D) and diffuse and constant expression for S-100 protein was confirmed (S-100, original magnification, 100).
Plexiform schwannoma arising from cauda equina A 61-year-old woman with rheumatoid arthritis (RA) presented with unprecedented progressive low back and bilateral lower leg dull-pain. She has a 10-year and 7year history of methotrexate and etanercept treatment for RA, respectively. Physical examination revealed the absence of neurologic compromise. There was no evidence of any skin pigmentation and familial history of neurogenic tumors. Plain radiographs of the lumbar spine revealed degenerative changes, especially at L2/L3 level (Fig. 1). The plain magnetic resonance imaging (MRI) revealed intradural low-intensity lesion on both T1- and T2-weighted images (Fig. 2, Left and Middle); however, which may have been overlooked without gadoliniumenhanced MRI (Gd-MRI). The succeeding Gd-MRI of lumbar spine clearly revealed a homogeneously enhanced intradural lesion that extended from L2 to L4 (Fig. 2, Right). Computed tomography revealed neither calcification of the lesion nor bone scalloping (data not shown). Taking all these findings including being under treatment
using methotrexate and etanercept for the treatment of RA into consideration, a malignant tumor such as malignant lymphoma was first considered as a differential diagnosis. Other radiologic differential diagnosis of the lesion includes schwannoma, meningioma, and so on. We conducted excisional biopsy of the lesion. After laminectomy from L2 to L4, dural sac was opened at midline and intradural plexiform tumor was found. En block total extirpation was successfully performed (Fig. 3, A and B). Histologic examination revealed spindle-shaped cells arranged in short bundles with foci of nuclear palisading (Fig. 3, C). Diffuse and constant expression for S-100 protein was confirmed (Fig. 3, D). Neither nuclear atypia nor mitotic figures were observed. These findings were consistent with benign plexiform schwannoma. The improvement of preoperative symptoms was confirmed soon after the operation. At the time of the latest follow-up, 1 year after the surgery, the patient was free of symptom without evidence of re-growth of the lesion. Spinal plexiform schwannoma is extremely rare and, to the best of our knowledge, only two such cases have been reported [1,2]. This is the first case of plexiform schwannoma arising at cauda equina.
Fig. 1. Plain radiographs of the lumbar spine revealed degenerative changes, especially at L2-3 level. http://dx.doi.org/10.1016/j.spinee.2014.09.005 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
206
K. Mori et al. / The Spine Journal 15 (2015) 205–206
Fig. 2. (Left) T1- and (Middle) T2-weighted preoperative magnetic resonance imaging (MRI) showing intradural low-intensity lesion. (Right) Gadoliniumenhanced MRI clearly revealed a homogeneously enhanced intradural lesion that extended from L2 to L4. Arrows indicates the level of axial views.
References [1] Sakaura H, Ohshima K, Iwasaki M, Yoshikawa H. Intra-extradural plexiform schwannoma of the cervical spine. Spine 2007;32:E611–4. [2] Capone F, Pravata E, Novello M, Moncelsi S, Pirronti T, Meglio M, et al. A rare case of life-threatening giant plexiform schwannoma. Spine J 2012;12:83.
Kanji Mori, MD, PhDa Shinji Imai, MD, PhDa Kazuya Nishizawa, MD, PhDa Akira Nakamura, MDa Mitsuaki Ishida, MD, PhDb Yoshitaka Matsusue, MD, PhDa a Department of Orthopaedic Surgery Shiga University of Medical Science
Tsukinowa-cho, Seta, Otsu Shiga, 520-2192, Japan b Department of Clinical Laboratory Medicine Shiga University of Medical Science Tsukinowa-cho, Seta, Otsu Shiga, 520-2192, Japan FDA device/drug status: Not applicable. Author disclosures: KM: Nothing to disclose. SI: Nothing to disclose. KN: Nothing to disclose. AN: Nothing to disclose. MI: Nothing to disclose. YM: Nothing to disclose.
Fig. 3. (A and B) Macroscopic findings of the tumor showed yellowish, well-circumscribed, and multilobulated lesion. (C) Histologic examination revealed spindle-shaped cells arranged in short bundles with foci of nuclear palisading (hematoxylin and eosin, original magnification, 100), (D) and diffuse and constant expression for S-100 protein was confirmed (S-100, original magnification, 100).
