MRI of intraspinal nerve sheath tumours presenting with sciatica

The magnetic resonance imaging (MRI) characteristics of 14 intraspinal nerve sheath tumours (NST) presenting with sciatica were reviewed. The group comprised seven schwannomas, six neurofibromas and one perineuroma. The tumours were either iso- or hypointense with respect to spinal cord on T1-weighted (T1W) images; almost all tumours were hyperintense compared with spinal cord on T2-weighted (T2W) images. The tumours were all detectable on unenhanced T1W images. Nine NST were scanned following Gadolinium-Diethylenetriamine penta acetic acid (DTPA) injection and all showed intense enhancement. This aids differentiation from sequestrated disc fragments. Tumours were more likely to show homogeneous enhancement unless they were recurrent tumours. Rim enhancement occurs more commonly in schwannomas and this can be used to differentiate these from neurofibromas. However, on unenhanced images, schwannomas cannot be distinguished from neurofibromas. Four tumours occurred at T11-T12. There was poor correlation of the site of the lesion with the clinical findings. MRI studies in patients with sciatica should include the lower thoracic region especially if no protruded disc was found in the lumbar region.     

Cystic lumbar nerve sheath tumours: MRI features in five patients

Intraspinal cystic lumbar nerve sheath tumours constitute an uncommon subset of tumours with distinct clinico‐biological behaviour. The MRI findings in five such cases are presented. Four of these were cystic schwannomas and one was a cystic neurofibroma. The pathology, MRI findings and the differential diagnosis of these rare tumours are analysed.     

Peripheral nerve sheath tumours: an ultrastructural study of 30 cases.

This report deals with the ultrastructural observations of 30 peripheral nerve sheath tumours [PNST], which include 25 schwannomas of acoustic nerve, one schwannoma of cauda equina, one neurofibroma from a case of Von Recklinghausen's disease, one pigmented neurofibroma of spinal nerve root and a malignant schwannoma of frontal region. Interdigitating slender cytoplasmic processes covered with a continuous layer of basal lamina constitute the single most important ultrastructural attribute of Schwann cells. Myelin formation was encountered in the cell processes of four out of 25 acoustic schwannomas. In four cases Microtubular arrays identical to that in an axon were seen in Schwann cells. These two observations require further support by additional cases of PNST studies by electron microscopy. The neurofibroma consisted only of Schwann cells and no ultrastructurally identifiable perineurial cells or fibroblasts were detected. The cells in the pigmented neurofibroma revealed submicroscopic features of both Schwann cell and melanocyte, indicating their common ancestry. A unique case of malignant schwannoma arising from frontal meninges is illustrated and it is emphasized that electron microscopy is mandatory for a correct histogenetic diagnosis of malignant tumours which occur at unexpected anatomical sites.     

Fluid–fluid levels in intracranial schwannomas

Intracranial cystic neurogenic tumours constitute an uncommon subset of tumours with a distinct clinico-biological behaviour. The presence of fluid–fluid levels within the tumours, although rare, confirms the cystic nature of the neoplasms. Barring the acoustic schwannomas, cystic cranial nerve schwannomas are exceptionally uncommon. Imaging findings of fluid–fluid levels in two non-acoustic cranial nerve schwannomas are described; one was a cystic trigeminal schwannoma and the other was a glossopharyngeal nerve schwannoma. The causes of the fluid–fluid level and its implications are analysed.     

Malignant schwannoma of the inferior dental nerve

Malignant schwannomas of the oral cavity and especially inferior dental nerve tumours, are rare malignancies. Mostly arising de novo as solitary tumours, some cases have occurred in Von Recklinghausen neurofibromatosis (25% of cases) or, as in the present report, at the time of a relapse by transformation of a benign schwannoma. Long survival is only observed in selected early diagnosed patients additionally treated by extended surgery. Support of magnetic resonance imaging and immunohistological techniques in diagnosis are stressed. Advances in reconstructive surgical devices after debulking surgery have contributed to enhance the performance of more curative procedures (hemimandibulectomy, intra oral resections) and to improve the functional and esthetic results in these bad prognosis nerve tumours of the oral cavity.     

Podoplanin and CD34 in peripheral nerve sheath tumours: focus on neurofibromatosis 1-associated atypical neurofibroma

Patients suffering from neurofibromatosis type 1 and 2 (NF1 and NF2) are the main risk groups to develop peripheral nerve sheath tumours (PNSTs). In the present study, adhesion molecules CD34 and podoplanin were assessed in regard to their value for tumour classification and as indicators for tumour progression. A total of 103 NF1-, NF2- and schwannomatosis-associated neurofibromas, schwannomas and malignant peripheral nerve sheath tumours (MPNST), as well as 20 sporadic vestibular schwannomas and 9 control tissue samples, were labelled immunohistochemically for detection of podoplanin and CD34. CD34 was shown to be expressed in MPNST and all benign PNSTs except for the compact cellular parts of both, schwannomas and atypical neurofibromas. Podoplanin showed an inverse expression pattern to CD34 labelling mainly the compact parts of schwannoma and atypical neurofibroma. MPNSTs were characterized by strong podoplanin staining at the invasive front. NF1-patients who suffered from atypical neurofibromas did not develop MPNST at a higher frequency than other NF1-patients, although these tumours expressed podoplanin. Ki-67 proliferation indices did not differ significantly between neurofibromas, atypical neurofibromas and schwannomas. In accordance with other studies, CD34 was found to be of limited value for classification and grading of PNST due to its ubiquitous expression. Podoplanin expression in schwannoma and atypical neurofibroma adds to other phenotypic and genotypic similarities between these tumours, like nuclear atypia, regressive changes and euploid polyploidisation. Podoplanin expression in atypical neurofibroma was not associated with tumour progression towards MPNST.     

磁共振成像和磁共振血管造影对颈动脉间隙肿瘤诊断价值分析

目的　探讨无创性磁共振成像 (MRI)和磁共振血管造影 (MRA)对颈动脉间隙肿瘤的诊断价值 ,及其对术前制定手术方案的作用。方法　对临床可疑或确诊为颈动脉间隙肿瘤的 2 6例患者进行了术前颈部MRI和MRA检查 ,观察病变的形态、边界、内部信号 ,病变与颈动脉、分支动脉和颈内静脉的关系 ,以及颈总动脉分叉角度。结果　在 2 2例经手术或活检病理证实的患者中 ,颈动脉体瘤14例 (15个 ) ,颈动脉瘤 4例 ,神经鞘瘤 3例 ,转移性低分化鳞状细胞癌 1例。另有 4例经MRI和MRA检查及临床随访证实 ,3例为一侧较对侧明显增粗的颈总动脉 ,1例为迂曲走行的颈总动脉。MRI结合MRA检查对本组颈动脉体瘤和颈动脉瘤术前诊断均正确 ,并且MRI、MRA原始像及MRA三维重建像可提供准确的肿瘤与颈动脉及分支的关系。结论　无创性MRI和MRA检查对颈动脉间隙肿瘤 ,特别对颈动脉体瘤和颈动脉瘤的诊断优于其他检查方法 ,可以替代以往所必须进行的有创性颈动脉造影。     

Orbital and myocardial metastases of a primary pulmonary melanotic schwannoma

We present the case of a 60-year-old man with a primary pulmonary melanotic schwannoma treated with surgery and who developed an orbital and myocardial relapse 2 years after the initial diagnosis. Melanotic schwannomas are rare pigmented tumours that tend to arise from the peripheral nerves near the midline. A primary lung presentation, as in our case, is extremely rare. In more than half of cases, the Carney triad of myxomas of the heart, skin and breast, spotty pigmentation and endocrine hyperactivity is present. A thorough pathological study is pivotal for a correct diagnosis. The main differential diagnosis is with metastases of malignant melanoma. The biological behaviour is unpredictable. Treatment should include radical surgery if possible; the role of chemotherapy and radiotherapy is uncertain due to the rarity of the tumour.     

Metastasising clear cell odontogenic carcinoma: a case report and review of the literature

Primary odontogenic carcinomas are rare and examples which have metastasised are even more uncommon. We describe the first reported case of a clear cell odontogenic carcinoma which metastasised to distant bones, namely the 5th lumbar vertebra and hip, 3 years after initial diagnosis. The initial incisional biopsy was thought to represent a calcifying epithelial odontogenic tumour, but in the subsequent resection the tumour showed a prominent clear cell component admixed with squamous cells showing peripheral palisading, widespread infiltration and necrosis indicating a malignant neoplasm. Radiologically guided biopsy revealed a metastatic lesion in L5 vertebrae and left hip, confirmed by immunohistochemistry. The metastatic lesion had similar appearances to the first biopsy, and diagnosis was confirmed by comparison of histological features, immunohistochemistry and exclusion of a second primary lesion by clinical examination and imaging. The diagnosis of clear cell odontogenic carcinoma is a difficult one to make. The behaviour of these tumours is unpredictable. This case confirms that clear cell odontogenic carcinomas have the potential for distant metastasis and require long-term follow up.     

Histological and cytological diagnosis of carcinoma of the oesophagus.

Endoscopic examination of the oesophagus accompanied by histological examination of biopsies or cytological examination of smears enables a confident diagnosis of carcinoma to be established within a period of 24-48 h and in the case of cytology within 15-60 min. Squamous cell carcinoma and adenocarcinoma are easily identified in biopsies or smears taken directly from the lesion. The histopathologist should be alerted to the possible diagnosis of Barrett's adenocarcinoma provided adequate information is given regarding the level of the squamo-columnar junction and the level of the targeted lesion. Unusual tumours are encountered rarely and they include carcinosarcoma, mucoepidermoid carcinoma, adenocystic carcinoma, carcinoid, malignant melanoma, oat cell carcinoma, spindle cell sarcoma, malignant lymphoma, Kaposi's sarcoma, etc. Special stains and multiple levels from the biopsies will be required for accurate identification of these tumours. Dysplasia constitutes a difficult diagnostic problem with reference to its significance regarding surveillance and treatment. Low grade dysplasia represents a recommendation for surveillance provided that the patient is regarded as a good surgical risk if cancer should develop at a later stage. High grade dysplasia is associated with a high risk of invasive cancer and close surveillance is required for the detection and treatment of invasive cancer provided also that the patient is a good surgical risk.     

Alpha-fetoprotein-producing non-germ cell tumours of the female genital tract

Elevated levels of alpha-fetoprotein (AFP), a foetal serum protein, occur mainly on the development of hepatocellular carcinoma (HCC) or germ cell tumours, including yolk sac tumour (YST) and embryonal carcinoma of the ovary. Rarely, other tumours of the female genital tract produce AFP. This article reviews the AFP-producing non-germ cell tumours reported in different parts of the female genital tract to date. These include different types of carcinomas and carcinosarcomas of the uterus, ovary and cervix and sex cord stromal tumours of the ovary. It is important for both pathologists and oncologists to be aware of such cases and the clinicopathological distinction from germ cell tumours, as the diagnosis would affect the management plan for the patient. The reviewed cases suggest that regardless of the patient’s age when no lesion is detected in the liver and stomach of a woman whose serum AFP level is abnormally high, the female reproductive system should be examined as a possible site of AFP-producing tumour. Biochemical, physiological and pathological features of AFP are briefly presented.     

Schwannoma of the hard palate

Schwannoma or neurilemmomas are benign, slow-growing, usually solitary, encapsulated tumors. They originate from the schwann cells of the nerve sheath. Approximately 30–40% of head and neck tumors are schwannomas. Intraoral schwannomas constitute a mere 1%. Tongue is the commonest site of schwannomas intraorally. Here we report a rare case of a hard palate swelling which was histopathologically diagnosed as schwannoma. The lesion was completely excised intraorally.     

Radiothérapie des tumeurs cérébrales : quelles marges ?

Radiotherapy is a major modality in the treatment of brain tumours. The target volumes definition has to be precise for the radiation planification. The gross target volume (GTV) is most of the time delineated within the fusion of the planning CT scan with the appropriated MRI sequences. The clinical target volume (CTV) definition is more complex: it varies in time following the evolution of scientific knowledge and also depending of the school of thought. This article offers a review of the literature about the margins applied in brain tumours radiotherapy for gliomas (high grade, anaplastic, low grade and brain stem gliomas), embryologic tumours (medulloblastomas and primitive neuroectodermal tumours [PNET]), ependymomas, atypical teratoid rahbdoid tumours (ATRT), craniopharyngiomas, pineal gland tumours, primary central nervous cell lymphomas, meningiomas and schwannomas. New imaging modalities such as diffusion-weighted imaging, dynamic contrast enhanced, spectroscopic MRI and PET scan will allow us to delineate more precisely the target volumes and to realise dose-painting by adapting the dose to the tumour metabolism.     

The role of monoclonal antibodies in brain tumour diagnosis and cerebrospinal fluid (CSF) cytology

Summary This paper reviews the diagnostic role of monoclonal antibody immunohistochemistry in a series of 189 brain tumour biopsies and 22 cases of neoplastic meningitis. The diagnostic monoclonal antibody panel, which includes markers for glial, neural, epithelial and lymphoid differentiation antigens, was used to test a wide variety of cerebral and spinal tumours by indirect immunofluorescence and immunoperoxidase techniques on unfixed frozen sections. Gliomas, meningiomas, schwannomas, medulloblastomas, choroid plexus tumours, cerebral lymphomas and metastatic carcinomas could all be reliably differentiated by means of their characterisctic antigenics profiles, as defined by their patterns of reactivity with the antibody panel. Confident diagnosis was possible even in very poorly differentiated tumours and in biopsies distorted by surgical squeeze artefact, where paucity of morphological clues made diagnosis by conventional histological methods difficult or impossible. It was estimated that use of the antibody panel was responsible for, or made a significant contribution towards the final diagnosis in approximately 20% of cases.The monoclonal reagents were also found to be of great value in the detection and characterisation of neoplastic cells in CSF specimens from patients with malignant meningitis. Malignant cells were detected in 73% of cases and characterised in 16% of cases by routine cytological techniques. Employing monoclonal immunocytology however, these figures were improved to 95% and 95% respectively. Our findings suggest that patients with neoplastic meningtitis can be spared prolonged investigation and inappropriate management by the early detection and characterisation of malignant cells in CSF using panels of monoclonal antibodies.     

Historadiological Correlation of Cerebellopontine Angle Tumors: Series of 122 Cases

Cerebellopontine angle (CPA) tumours, are diverse pathologically with regard to the site of tumour origin and displacement of the neurovascular structures. In general CPA tumours are divided into acoustic and non-acoustic tumours. The aim of the present study was to see the spectrum of lesions at cerebellopontine angle and their historadiological correlation. A retrospective analysis of 122 cases of CPA tumors diagnosed in the Department of Pathology, IHBAS was done from January 2004 to August 2019. There were 56 males and 66 females in the age group of 8–68 years. Clinical history ranged from 10 days to 5 years. Clinical symptoms included hearing deficit, visual loss, facial nerve dysfunction, nausea, vomiting, headache, seizures, unsteadiness and disequilibrium. Historadiological correlation was found in 112 cases (91%).In our series of CPA tumors, nonacoustic tumors were more frequent than in previous studies. We found that presence of intrameatal fraction is not exclusive only for schwannomas. There can be a rare occurrence of medullobastoma/small round cell tumor in CP angle. The final pathological verification can at times give unexpected results. Immunohistochemistry did not have a significant role in diagnosis of cerebellopontine angle tumors.     

The bony crescent sign -a new sign of facial nerve schwannoma

Schwannomas of the facial nerve are rare slowly growing lesions that have a predilection for the geniculate ganglion. Radiological evaluation is important in their diagnosis and in the assessment of their extent. In our series of 4 cases the facial nerve schwannoma was seen on high resolution CT as a soft tissue mass bounded anteriorly by a thin rim of bone. This bony crescent sign is a previously undescribed sign of facial nerve schwannoma which appears on the basis of this small series to be strongly indicative of the presence of this tumour. Schwannomas are relatively uncommon intracranial tumours. They most commonly involve the acoustic nerve followed in frequency by the trigeminal nerve. Other cranial nerves are rarely involved. Facial nerve schwannomas occur ring within the petrous temporal bone are very rare. Their diagnosis may be missed prospectively even when appropriate CT scans are per formed. Even in retrospect the site of abnormality may be difficult to identify, especially if there is an associated middle ear mass such as a cholesteatoma. Lesions occurring in the petrous area are all rare. The differential diagnosis includes cholesterol granuloma, epidermoid, carotid aneurysm and, very rarely, primary and secondary bone tumours. We describe a new sign associated with facial nerve schwannoma on CT, that of a bony crescent. Recognition of this sign makes those tumours arising in the region of the geniculate ganglion easy to diagnose prospectively.     

Bilateral malignant phyllodes tumours.

We report a rare example of bilateral primary malignant phyllodes tumours. The diagnosis was supported by the identification of a benign epithelial element in each lesion. The case illustrates the typical dimorphic features of malignant phyllodes tumours. A contralateral tumour should not be regarded as metastatic without histological confirmation.     

The idiosyncratic relationship between diagnostic delay and stage of oral squamous cell carcinoma

Approximately half of patients with oral cancer present with advanced lesions when five-year survival rates are as low as 20%, however, diagnostic delay has repeatedly been found to be unrelated to the stage of oral cancer at diagnosis. The aim of this study was to investigate why diagnostic delay is frequently unrelated to the stage of oral cancer at diagnosis. The odds ratio (OR) of early versus advanced oral squamous cell carcinoma was calculated for 245 consecutive patients with untreated oral squamous cell carcinoma. Being female (OR=0.40; 0.19-0.80; p<0.05) and married (OR=0.27; 0.11-0.66; p<0.01) was predictive of early stage disease. Being non-white (OR=5.42; 1.66-17.67; p<0.01) was predictive of advanced stage disease. There is no evidence that these patient demographics are associated with faster growing tumours, yet it is possible that those who are male, unmarried and non-white may not notice an oral lesion until it is advanced in stage. It is concluded that differences in tumour biology are not a likely explanation for the absence of a delay-stage relationship but instead, a proportion of tumours may be silent until advanced in stage.     

Rare thoracic mass lesion--myofibrobastoma

Mesenchymal soft tissue masses are uncommon tumours of the chest. Myofibroblastoma is a recently described entity consisting of cells with origin from the myoepethelial cell, mostly seen as benign well-circumscribed neoplasms of the breast tissue. Though usually classified as a benign lesion, rarely it can be multifocal and prone to recurrence. We describe below the case of a 26-year-old female who presented with exertional dyspnoea and evidence of a massive mass lesion in the left hemithorax causing mediastinal displacement to the opposite side. On histological and immunophenotypic analysis, a diagnosis of the very rare thoracic myofibroblastoma was made. The incidence, salient features, pathological differential diagnoses and treatment are reviewed.     

Contribution of cytogenetics to the diagnosis of Ewing's sarcoma and small round cell tumors]

The diagnosis of the so-called "small-round-cell tumours" in children and adolescents is a troublesome problem, particularly in specific forms of the disease or/and in undifferentiated cell proliferations. Under these circumstances the finding of a specific chromosomal abnormality in the tumour cells is invaluable, specially for the diagnosis of Ewing sarcoma and primitive neuroectodermal tumours as well as alveolar rhabdomyosarcoma. The use of cytogenetics, in combination with morphological and immunohistochemical studies to identify cell differentiation markers, is either the only positive diagnostic criterion, or a complementary factor in diagnosis.