Schwannoma of the Hand: Importance of Differential Diagnosis & Microsurgical Dissection

PURPOSE: The schwannoma is a benign peripheral nerve tumor arising from the Schwann cell of the nerve sheath. Only 2-8% of schwannomas arise in the hand and wrist. Misdiagnosis is frequent such as ganglion and neurofibroma. This article documents and clarifies the clinical features of schwannomas arising in the hand and wrist, and emphasizes importance of differential diagnosis and meticulous surgical extirpation under magnification. METHODS: The author reviewed clinical features of 15 patients with pathologic final diagnosis of schwannoma developed in hand and wrist during the last 12 years from 1998 through 2009. The review included the sex, age of onset, duration, preoperative diagnosis, location, involved nerve, preoperative symptoms and. Postoperative sequelae after surgical extirpation of the lesion with magnification, or without magnification of the surgical fields. RESULTS: The chief complaints were slow growing firm mass in all patients, and followed by pain in 40%, and paresthesia in 40% respectively. The lesions were developed solitarily in 14 patients(93%). The postoperative pathologic diagnosis and preoperative diagnosis were coincided with only in 6 patients(40%). Other preoperative diagnosis were soft tissue tumor in 4 patient(26.6%), and ganglion in 3 patients(20%), and neurofibroma in 2 patients(13%). In all patients who were undergone surgical excision under the fields of magnification, all symptoms were subsided without any sequelae. Meanwhile muscle weakness, paresthesia, hypoesthesia and/or accidental nerve resection developed after surgical excision with naked eye. CONCLUSION: Schwannoma in hand most commonly appears as a slow growing solitary mass with pain or paresthesia. The chance of preoperative misdiagnosis was 60% in this series. To provide good prognosis and less sequelae, careful and elaborate diagnostic efforts and meticulous surgical excision under the magnification are necessary in management of schwannoma.

Operative Treatments in Syringomyelia Caused by Trauma or Arachnoiditis

OBJECTIVE: Most cases of syringomyelia with arachnoid scarring were related to spinal trauma or inflammatory reaction. The aim of this study is to analyze the influence of arachnoid scarring on the altered dynamics of cerebrospinal fluid(CSF) and determine the proper treatment. METHODS: Between Jan 1991 and Dec 2001, We have operated on 15 patients with progressive neurological deficits associated with syringomyelia. We analyze the clinical presentations, radiographic and magnetic resonance images. RESULTS: As to cause of syringomyelia, 11 patients were related with trauma and 4 patients were tuberculous meningitis. Shunting procedures underwent in 11 patients and 5 showed clinical improvement. Subarachnoid adhesiolysis and expansile duraplasty were performed in 4 patients and 3 experienced clinical improvement. The 6 patients with shunting procedures were neurologically deteriorated and 4 were reoperated. CONCLUSION: The arachnoid scarring interferes with CSF flow and causes syringomyelia. Successful long-term outcome in the surgical treatment of syringomyelia caused by focal arachnoid scar appeared to require microsurgical dissection of scar and expansile duroplasty. For extensive arachnoid scarring over multiple spinal levels or after previous surgery, shunting procedure may be indicated only.

Dificuldades na microdissecção da fissura e da cisterna silvianas / Technical difficulties in the microsurgical dissection of the sylvian fissure and cistern

Os sulcos, as fissuras e as cisternas subaracnóideas são vias naturais de circulação do líquido cefalorraquidiano que podem ser utilizadas pelo cirurgião para alcançar regiões mais profundas do cérebro e da base do crânio. Dessas vias, as mais utilizadas na prática neurocirúrgica são afissura e a cisterna silvianas. No entanto, apesar da ampla divulgação da técnica, nem sempre a microdissecção desses espaços é simples e, por vezes, mesmo o neurocirurgião experiente e persistente encontra dificuldades técnicas em executá-la. Com a finalidade de detectar os fatores que contribuem para essas dificuldades, analisamos 10variáveis observadas em 152 pacientes submetidos ao tratamento cirúrgico de aneurismas da circulação anterior do polígono de Willis por via pterional, que foram confrontadas com o resultado da dissecção. As ocorrências cirúrgicas ? lesão pial extensa na superfície dos opérculos e tempo de dissecção da fissura e da cisterna silvianas maior que 60 minutos ? foram assumidas como evidências indiretas de dificuldade técnica na dissecção e consideradas, isoladamente ou em conjunto, como representativas de uma dissecção difícil. O percentual de casos com fissura e cisterna silvianas de difícil dissecção foi significantementemaior nos pacientes que apresentavam membrana aracnóide espessa, aderência moderada ou intensa entre os opérculos frontal e temporal, cisterna silviana virtual e veia silviana superficial com calibre maior que 3 milímetros. No entanto, quando empregada a técnica de regressãologística múltipla para estudar o efeito conjunto dessas variáveis na probabilidade da dissecção ser difícil, somente as duas primeiras apresentaram significância estatística (p = 0,005 e p = 0,015, respectivamente). A probabilidade de uma dissecção difícil da fissura e da cisterna silvianas é 2,76 vezes maior nos pacientes que têm uma membrana aracnóide espessa e 3,11 vezes maior quando a aderência entre os opérculos é moderada ou intensa. Quando o paciente não apresenta nenhuma das duas variáveis consideradas como fatores de risco, a probabilidade estimada de uma dissecção difícil é de apenas 12%. Por outro lado, quando ambos fatores estão presentes, essa probabilidade sobe para 53%. A ocorrência de uma lesão pial extensa ou a necessidade de um tempo cirúrgico maior que 60 minutos para uma dissecção completa da fissura e da cisterna silvianas não teve relação direta com qualquer tipo de repercussão clínica. Levando em consideração essa constatação e a impor tância fundamental da aber tura por microdissecção da fissura e da cisterna silvianas na via de acesso pterional, podemos concluir que a existência de dificuldades técnicas não invalida a execução dessa etapa cirúrgica.

The sulci, fissures and subarachnoid cisterns are natural pathaways of circulation of the cerebrospinal fluid that may be used by the surgeon to reach deep regions of the brain and the skull base. Among these routes, the sylvian fissure and cistern is the most commonly utilized in the neurosurgical practice. The surgical microdissection of these spaces is not always simple and even the most tenacious and experienced surgeon finds it difficult at times. With the purpose of detecting the factors that might contribute to these technical difficulties during the microsurgical dissection of the sylvian fissure and cistern we have analysed 10 variablesobserved during 152 surgical procedures carried through the pterional route for the treatment of aneurysms of the anterior circulation. These variables were confronted with the dissection results. The surgical occurrence of extensive pial lesion and extended microsurgical dissection time (over 60 minutes) were considered as indirect evidence of technical difficulty during dissection and representative of a difficult dissection.