Intracranial Metastases from Prostate Carcinoma: Classification, Management, and Prognostication.

BACKGROUND: Prostate carcinomas rarely metastasize to the central nervous system but, when they do, dural localizations are as common as and far more aggressive than intraparenchymal ones. Those metastases can be further classified according to their extension toward the subdural or extradural space and can frequently simulate other pathologic conditions including chronic subdural hematomas, abscess, and primary bone tumors. Beside the challenges of the preoperative differential diagnostic and complexity of surgical planning and operative excision, subdural metastases seem to carry a much poorer prognosis. METHODS: A series of consecutive patients admitted during a 12-year period through our oncall pathway for subdural/extradural collections or intraparenchymal lesions found, on histologic analysis, to represent intracranial prostate cancer metastases was retrospectively reviewed. RESULTS: A total of 19 patients were included, but only 3 were diagnosed with small cell prostate carcinoma, while the majority had a primary prostate adenocarcinoma. Metastases could be classified as pure subdural space lesions, dural-based lesions, extradural/bony lesions, and pure intraparenchymal lesions. All patients with subdural metastases and 3 out of 5 patients with dural-based lesions required an emergency intervention due to rapidly deteriorating neurologic status. The mean follow-up in our series was 37 months; only subdural localizations had a remarkably unfavorable outcome. CONCLUSIONS: Supported by our experience and the review of the literature, we suggest that a low threshold for contrast-enhanced computed tomography/magnetic resonance imaging is advisable in case of suspicious subdural collection, even in an emergency setting, for patients with previous medical history of prostate cancer.

[Tumors of the skull base, extending into the orbit, paranasal sinuses, nasal cavity, pterygopalatine and infratemporal fossa].

The first of two papers focusing on surgery of skull base tumors invading orbit, sinonasal cavities, pterygopalatine and infratemporal fossae the authors described foundation and development of craniofacial oncology as a new discipline in skull base surgery, modern approaches to diagnostic evaluation of craniofacial mass lesions and basic principles of surgical management.

Metastatic skull tumors: MRI features and a new conventional classification.

Skull metastases are malignant bone tumors which are increasing in incidence. The objectives of this study were to characterize the MR imaging features, locations, and extent of metastatic skull tumors to determine the frequency of the symptomatic disease, and to assess patient outcomes. Between September 2002 and March 2008, 175 patients undergoing routine head MR imaging were found to have metastatic skull tumors. Contrast-enhanced study with fat suppression was used in some cases when required. Classification of metastases was simplified to three yes/no questions: first, with regard to location (either in the calvarium or in the cranial base); second, with regard to distribution within the plane of the cranial bone (either "circumscribed" meaning clearly demarcated and confined to one bone, or "diffuse" and likely to spread across a suture to another bone); and third, with regard to invasion ("intraosseous" in cranial bones only, or "invasive" spreading from the skull, either out into the scalp or inward to the dura and perhaps further in). Primary sites were breast cancer (55%), lung cancer (14%), prostate cancer (6%), malignant lymphoma (5%), and others (20%). The mean time from primary diagnosis to skull metastasis diagnosis was 71 months for cases of breast cancer, 26 months for prostate cancer, 9 months for lung cancer, and 4 months for malignant lymphoma. Calvarial circumscribed intraosseous metastases were found most frequently (27%). The patients were mainly asymptomatic. However, some patients suffered from local pain or cranial nerve palsies that harmed their quality of life. Treatment, mainly for symptomatic cases, was by local or whole-skull irradiation. Metastatic skull tumors are not rare, and most are calvarial circumscribed intraosseous tumors. MR images contribute to understanding their type, location, and multiplicity, and their relationship to the brain, cranial nerves, and dural sinuses. Radiation therapy improved the QOL of patients with neurological symptoms.

Protuberant fibro-osseous lesion of the temporal bone: "Bullough lesion".

Primary tumors of the calvarium are infrequent, and with the exception of osteoma, lesions confined to the surface of the skull are very rare. The differential diagnosis includes benign and malignant matrix forming tumors, other mesenchymal tumors, and reactive lesions. Fibro-osseous lesions are characteristically centered within bone and surface fibro-osseous lesions always prompt consideration of parosteal osteosarcoma, which is rare but well documented in the calvarium. We present 2 cases of a distinctive lesion of the temporal bone intimately related to the occipito-mastoid suture and typically presenting as a retroauricular soft tissue mass with calcific densities, confined to the soft tissues on the outer table of the skull without intraosseous involvement. The lesion is characterized histologically by rounded and ovoid zones of ossification within a bland fibrous stroma. The first 2 cases were documented in 1999 as "Protuberant fibroosseous lesion of the temporal bone.:" We present a further 2 cases, 1 of 2 years duration and the other with a 10-year history. This distinctive entity, which must be distinguished from other fibro-osseous lesions, including subtle low-grade parosteal osteosarcoma, seems to behave in a benign fashion and thus far recurrence is not documented. Local excision seems adequate. The pathologic features in the original report were documented by Prof Peter Bullough. As these cases were recognized by him alone we propose calling this entity "Bullough lesion" or, better still, "Bullough's Bump!"

The classification of posterior petrous meningiomas and its clinical significance.

This retrospective analysis of the clinical records of 42 patients was used to study the clinical significance of a classification system for posterior petrous meningiomas. According to clinical manifestations and radiological images, posterior petrous meningiomas were classified into three types: type I (cerebella type; 12 patients), tumours involved and compressed the cerebellum; type II (cranial nerve type; 16 patients), tumours involved the cranial nerves; and type III (combined type; 14 patients), tumours involved more than one structure such as the cerebellum, cranial nerves and the brain stem. All patients underwent microneurosurgery and the total resection rate was 90%. It was more difficult totally to resect type II and III tumours than type I tumours and the post-operative functional outcomes were worse. Microneurosurgical techniques and skills are critical to increase the total resection rate of posterior petrous meningiomas in order to decrease the mortality and disability rates.

[Topographic variants of cranial chordomas].

The objective of this study was to investigate variants of localization of cranial chordomas. We examined 220 patients treated in Burdenko Neurosurgical Institute (Moscow, Russia) since 1985 till 2007. In the vast majority of cases (93%) tumors were localized in sellar region (34%), clivus (32%) and craniovertebral junction (27%). As addition to previously suggested classifications we distinguish special group of craniofacial chordomas (5%). Although chordomas are theoretically midline tumors, according to our data in many cases (40%) they may be lateralized.

Bilateral parieto-occipital dermoid sinuses in a Rottweiler.

Bilateral dermoid sinuses were identified on the parieto-occipital region of a Rottweiler. Diagnosis was confirmed by histological examination after successful complete surgical resection. The dermoid sinuses were independent with separate tracts. This unusual parasagittal location can be explained by craniofacial development: dermoid sinuses on the head could occur along the lines of embryological fusion and not only in the sagittal plane. A hypothesis of an origin at the level of the suture between the parietal and interparietal bones is possible in this case.

Radiosurgery for miscellaneous skull base tumors.

Stereotactic radiosurgery has become an integral part of conventional and advanced skull base surgery. Despite the advances in skull base techniques, the goal of total resection of such tumors is often problematic and associated with significant risk to critical structures of the skull base, including those within the cavernous sinus, those in the petrous apex, and the jugular bulb. Aggressive resection of such tumors sometimes results in severe adverse neurological events, ranging from permanent extraocular movement deficits to hearing loss, facial weakness, and difficulties with vagal and glossopharyngeal function. Gamma Knife radiosurgery is a primary alternative option for these patients. It minimizes the risks of open surgical techniques and preserves existing cranial nerve function in most patients and achieves tumor growth arrest. Adjuvant radiosurgery is used for larger tumors after their initial partial resection. Gamma Knife radiosurgery becomes an adjuvant tool to provide longterm tumor growth control of a significantly reduced tumor volume.

Tumores não hipofisários da região selar / Nonpituitary tumors of the sellar region

A hipófise, a sela túrcica e a região peri-selar podem ser acometidas por uma série de lesões, incluindo tumores benignos e malignos, bem como uma ampla variedade de doenças não neoplásicas. Os aspectos clínicos e radiológicos podem auxiliar no diagnóstico diferencial destas lesões. Porém, em muitos casos, somente a análise histopatológica pode estabelecer o diagnóstico definitivo. Neste artigo, revisamos principais tumores não hipofisários da região selar e peri-selar, ressaltando seus aspectos endócrinos mais relevantes.

[Nonpituitary tumors of the sellar region]. / Tumores não hipofisários da região selar.

The pituitary gland, sella turcica and the parasellar region can be involved by a wide variety of lesions, including benign and malignant neoplasms as well as a wide variety of non neoplastic tumor-like lesions. Clinical and radiological aspects could help in the differential diagnosis of these lesions. Nevertheless, in many cases only the histopathological analysis could establish the definitive diagnosis. In this paper, we review the nonpituitary tumors of the sellar region emphasizing the associated hormonal disturbances.

A new classification for malignant tumors involving the anterior skull base.

OBJECTIVES: To propose our clinical classification of malignant ethmoid tumors and to compare it with the last American Joint Committee on Cancer (AJCC)-Union Internationale Contre le Cancer (UICC) classification, published in 1997. DESIGN: Retrospective review. SETTING: Tertiary cancer facility. PATIENTS: We evaluated 123 consecutive patients undergoing craniofacial resection for malignant ethmoid tumors involving the anterior skull base. The mean follow-up was 60 months. Fifty-nine patients (48%) presented with recurrent disease after prior therapy. We classified them with a new classification system (Istituto Nazionale per lo Studio e la Cura dei Tumori) based on the most commonly accepted unfavorable prognostic factors (involvement of dura mater; intradural extension; involvement of the orbit and, in particular, of its apex; invasion of maxillary, frontal, and/or sphenoid sinuses; and invasion of the infratemporal fossa and skin. We also classified patients with the AJCC classification published in 1997. MAIN OUTCOME MEASURES: Disease-free status and overall survival rate. To study a possible association with tumor stage, the Cox regression model was adopted. RESULTS: According to our classification, patient distribution by tumor type was T2, n = 46; T3, n = 29; and T4, n = 48 (no T1 tumors were present in the series). For previously untreated patients, 5-year disease-free survival estimates were T2, 57%; T3, 50%; and T4, 13%. For relapses, corresponding figures were T2, 31%; T3, 23%; and T4, 1%. The prognostic difference among stages was statistically significant (P<.001). Similar results were obtained for overall survival. In contrast, patient distribution among different AJCC stages was less balanced, and we failed to detect a significant association with the clinical outcome using this classification. CONCLUSION: We propose the use of our staging system by all those specialists in the field willing to validate the classification and possibly apply it for clinical and investigational purposes.

Cranial osteomas: their classification and management. Report on a giant osteoma and review of the literature.

BACKGROUND: Cranial osteomas are regarded by some as very common; yet their classification, symptomatology, and management have been neglected. METHODS: We report on a giant enostotic convexity osteoma and have reviewed the medical literature. RESULTS: A new comprehensive classification for cranial osteomas is proposed: (1) intraparenchymal, (2) dural, (3) skull base, and (4) skull vault. The latter is in turn, subdivided into exostotic and enostotic variants. Three symptom producing enostotic convexity osteomas have been reported in the world literature. We also describe a giant enostotic skull vault osteoma and propose an original surgical technique used to successfully resect this unusual tumor. CONCLUSIONS: Most cranial osteomas are asymptomatic and need not be resected. Those that are symptomatic should be managed properly. Their excision, if nor properly performed, may lead to unforeseen cerebral complications.

Maxillofacial fibro-osseous lesions: classification and differential diagnosis.

A large diversity of lesions may involve the maxillofacial bones. Some occur exclusively at this site. Other lesions at this location have features that are different from similar lesions occurring elsewhere in the skeleton. This site-dependent morphology applies especially to fibro-osseous lesions, which will be discussed in this report. Fibrous dysplasia shows evenly distributed islands of woven bone that fuse with surrounding bone. The presence of lamellar bone and osteoblastic rimming does not contradict that diagnosis as they would for lesions occurring outside the maxillofacial bones. Ossifying fibromas are demarcated or encapsulated. They show a broad variation in mineralized material that may be woven bone as well as lamellar bone or may be present as rounded cell-poor particles regarded as a form of cementum. Specific subtypes are juvenile ossifying fibroma and psammomatoid ossifying fibroma, both of which contain cellular stroma exhibiting mitotic activity. Lesions known as periapical cemental dysplasia can be found in the tooth-bearing jaw area and are similar to ossifying fibroma but without demarcation. These lesions may be focal, involving one or a few adjacent teeth; when they are more widely distributed, they are named florid cemento-osseous dysplasia. Periapical cemental dysplasia should be distinguished from cementoblastoma, a lesion similar to osteoblastoma but connected with tooth apices. Ossifying fibroma may resemble well-differentiated osteosarcoma as ossifying fibroma may be more cellular and may have a higher number of mitoses than osteosarcoma.

Chondroid chordoma. A hyalinized chordoma without cartilaginous differentiation.

"Chondroid chordoma" is a controversial and confusing entity that was originally described by Heffelfinger and colleagues as a biphasic malignant neoplasm possessing elements of both chordoma and cartilaginous tissue. Because the premise for this distinction was based strictly on histomorphologic criteria, the light microscopic, immunohistochemical, and electron microscopic features of the chondroid and chordoid areas of five chondroid chordomas of the skull base were evaluated separately, and compared to five typical chordomas and six low grade chondrosarcomas. Using light microscopy, chondroid chordoma revealed areas that resembled typical chordoma (chordoid areas) and areas that resembled low grade chondrosarcoma (chondroid areas). However, both the chordoid and chondroid areas had an epithelial phenotype and stained strongly for cytokeratin and EMA as well as S-100. 5'-nucleotidase, an enzyme that has been described in chordoma but not in chondrosarcoma, was found in both the chordoid and chondroid areas of one chondroid chordoma. Electron microscopic studies of both the chordoid and chondroid areas in four of the tumors demonstrated both tonofibrils and desmosomes. Chordoma demonstrated immunohistochemical and electron microscopic features that were nearly identical to chondroid chordoma. Chordoma was cytokeratin, EMA, S-100, and 5'-nucleotidase positive. Ultrastructurally, chordoma exhibited variably-sized vacuoles, abundant rough endoplasmic reticulum (RER), and desmosomes with tonofilaments. In contrast to chondroid chordoma, chondrosarcoma consistently stained for only S-100 protein and was cytokeratin, EMA and 5'-nucleotidase negative. Ultrastructurally, chondrosarcoma demonstrated a flocculogranular matrix, glycogen, abundant RER, and scalloped cellular outlines, but lacked desmosomes with tonofilaments. These findings indicate that "chondroid chordoma" is a variant of chordoma with histologic features that may mimic chondrosarcoma. Despite the resemblance of these hyalinized areas to cartilaginous tissue, these tumors retain their epithelial phenotype. Biphasic differentiation is not present. These findings undermine the original premise for distinguishing "chondroid chordoma" from typical chordoma. The authors propose that these tumors be classified as "hyalinized chordomas," rather than "chondroid chordoma," to clarify their histogenesis and avoid confusion with chondrosarcomas of the base of the skull.

Evaluation of partial classification algorithms using ROC curves.

When using computer programs for decision support in clinical routine, an assessment or a comparison of the underlying classification algorithms is essential. In classical (forced) classification, the classification rule always selects exactly one alternative. A number of proven discriminant measures are available here, e.g.sensitivity and error rate. For probabilistic classification, a series of additional measures has been developed [1]. However, for many clinical applications, there are models where an observation is classified into several classes (partial classification), e.g., models from artificial intelligence, decision analysis, or fuzzy set theory. In partial classification, the discriminatory ability (Murphy) can be adjusted a priori to any level, in most practical cases. Here the usual measures do not apply. We investigate the preconditions for assessment and comparison based on medical decision theory. We focus on problems in the medical domain and establish a methodological framework. When using partial classification procedures, a ROC analysis in the classical sense is no longer appropriate. In forced classification for two classes, the problem is to find a cutoff point on the ROC curve; while in partial classification, you have to find two of them. They characterize the elements being classified as coming from both classes. This extends to several classes. We propose measures corresponding to the usual discriminant measures for forced classification (e.g., sensitivity and error rate) and demonstrate the effects using the ROC approach. For this purpose, we extend the existing method for forced classification in a mathematically sound manner. Algorithms for the construction of thresholds can easily be adapted. Two specific measurement models, based on parametric and non-parametric approaches, will be introduced. The basic methodology is suitable for all partial classification problems, whereas the extended ROC analysis assumes a rank order of the selected alternatives. The method is based on the black box principle and makes use only of the results of the compared algorithms and some general intuitive principles. Therefore, algorithms arising from different "philosophical" approaches may also be compared according to their results. For demonstration purposes, a clinical example from cranial computed tomography is presented. Linear discriminant analysis as a reference is compared to a Bayesian and a fuzzy procedure.

[Cranio-cerebral dermoid and epidermoid cysts. Classification and pathogenesis]. / Les kystes dermoïdes et épidermoïdes crânio-encéphaliques. Classification et pathogénie.

The pathogenesis of cranial dermoids and epidermoids is still controversial, owing to the multiple etiologies and locations of these lesions. We reviewed 25 cases, classified as follows: extradural lesion of the calvarium; of the occipital squama; dysraphic occipital lesions; and strictly intradural lesions. In the latter group, all lesions but one were in a paramedian, prenevraxial situation, and could be classified according to their situation relative to the tentorium cerebelli. In our series, strictly intradural dermoids are more often in a rostral situation, and epidermoids in a more caudal situation. Dermoids appear earlier in life than epidermoids, suggesting a more rapid growth due to eccrine secretion. For each group of lesions, the pathogenic hypotheses are studied. Inclusion of epidermal nests at different levels might result from traumatism, dysraphism, or developmental trouble in the lamination of the different layers of the meninges. Most intradural lesions trent to be related to the formation of Rathke's pouch and closure of the anterior neuropore.

Tumors of the skull base: outcome and survival analysis of 77 cases.

We reviewed our experience with combined approaches to lesions that transcend the bones of the skull base. Seventy-seven skull base procedures were performed on 73 patients during a 10-year period from 1982 to 1992. There were 34 patients (44%) with region lesions (anterior), seven patients (9%) with region II lesions (anterior-lateral), 25 patients (32%) with region III lesions (lateral-posterior), and 11 patients (14%) with lesions that invaded more than one anatomic site. The histopathology in this series was quite variable, with 22 patients (29%) having squamous cell carcinoma and eight patients (10%) having basal cell carcinoma. Forty-one patients had surgery by an anterior approach and 38 patients had lateral approaches, with 18 undergoing an infratemporal approach and 29 undergoing temporal bone resections. Overall, 44% of the patients had a postoperative complication. Survival of this heterogeneous group of patients is 79% at 2 years and 71% at 4 years, with those patients with region II disease having a statistically significant poorer prognosis with no survivors at 4 years.

Chondroid chordoma versus low-grade chondrosarcoma of the base of the skull: can immunohistochemistry resolve the controversy?

The classification of cartilaginous tumors of the skull base, including chondroid chordoma and chondrosarcoma remains the subject of controversy. Critical review of the literature and our own experience of chordomas and cartilaginous tumors of the skull base led to the following conclusions: 1) Chondrosarcoma of the skull base is a distinct clinicopathological entity. The immunohistochemical staining pattern (cytokeratin negative, epithelial membrane antigen (EMA) negative) can be helpful in distinguishing it from chordoma with chondroid differentiation (cytokeratin positive, EMA positive). 2) The chondroid chordomas originally described by Heffelfinger et al. may have included some true chondrosarcomas with focal areas of myxoid chordomalike appearance. 3) Focal chondroid differentiation in chordoma is not such a rare phenomenon. Further study is needed to define whether chordoma with chondroid foci should be separated out from conventional chordoma as a distinct entity with a better prognosis.

Reclassification of aggressive adenomatous mastoid neoplasms as endolymphatic sac tumors.

The emerging concept that aggressive adenomatous tumors of the temporal bone arise from the endolymphatic sac and constitute a distinct clinicopathologic entity merits wider recognition. These tumors share a common clinical pattern and exhibit consistent imaging and histopathologic features. Endolymphatic sac tumors (ELSTs) have been mistaken for other neoplasms such as paragangliomas, adenomatous tumors of mixed histology, ceruminomas, and choroid plexus papillomas. A review of the literature shows similarities among case studies of these aggressive adenomatous lesions. An analysis of the data supports the endolymphatic sac as an origin for these tumors. This report also presents an additional case of a less differentiated variant of this rare but important clinicopathologic entity.