Recurrent atypical teratoid/rhabdoid tumors (AT/RT) reveal discrete features of progression on histology, epigenetics, copy number profiling, and transcriptomics

Atypical teratoid/rhabdoid tumors (AT/RT) are the most common malignant brain tumors manifesting in infancy. They split into four molecular types. The major three (AT/RT-SHH, AT/RT-TYR, and AT/RT-MYC) all carry mutations in SMARCB1, the fourth quantitatively smaller type is characterized by SMARCA4 mutations (AT/RT-SMARCA4). Molecular characteristics of disease recurrence or metastatic spread, which go along with a particularly dismal outcome, are currently unclear. Here, we investigated tumor tissue from 26 patients affected by AT/RT to identify signatures of recurrences in comparison with matched primary tumor samples. Microscopically, AT/RT recurrences demonstrated a loss of architecture and significantly enhanced mitotic activity as compared to their related primary tumors. Based on DNA methylation profiling, primary tumor and related recurrence were grossly similar, but three out of 26 tumors belonged to a different molecular type or subtype after second surgery compared to related primary lesions. Copy number variations (CNVs) differed in six cases, showing novel gains on chromosome 1q or losses of chromosome 10 in recurrences as the most frequent alterations. To consolidate these observations, our cohort was combined with a data set of unmatched primary and recurrent AT/RT, which demonstrated chromosome 1q gain and 10 loss in 18% (n = 7) and 11% (n = 4) of the recurrences (n = 38) as compared to 7% (n = 3) and 0% (n = 0) in the primary tumors (n = 44), respectively. Similar to the observations made by DNA methylation profiling, RNA sequencing of our cohort revealed AT/RT primary tumors and matched recurrences clustering closely together. However, a number of genes showed significantly altered expression in AT/RT-SHH recurrences. Many of them are known tumor driving growth factors, involved in embryonal development and tumorigenesis, or are cell-cycle-associated. Overall, our work identifies subtle molecular changes that occur in the course of the disease and that may help define novel therapeutic targets for AT/RT recurrences.

Lipomatous tumours in adrenal gland: WHO updates and clinical implications

Adrenal lipomatous tumour is a group of adrenal tumours with a significant component of adipose tissue. According to the current World Health Organization (WHO) classification of tumours of endocrine organs, adrenal myelolipoma is the only entity amongst the group of tumours being described. In the literature, other more recently documented adrenal lipomatous tumours included 24 lipomas, 32 teratomas and 16 angiomyolipomas. Rare fatty tumours of the adrenal gland comprised liposarcoma, hibernoma, adrenocortical tumours with fat component and rare adrenal tumours with fat component. Myelolipoma comprises approximately 3% of primary adrenal tumour. It is noted more commonly in females and in the right adrenal gland. Approximately 40 bilateral myelolipomas were reported. The tumour is most frequently recorded in patients between fifth and seventh decades of life. Adrenal lipomas are often seen in males and in the right adrenal gland. They were commonly noted in patients in the sixth decade of life. The diagnosis could only be possible on examination of the surgically removed specimen. Adrenal teratomas were more common in females and with a bimodal age distribution. Slightly over 60% of the patients with adrenal teratoma are symptomatic. Adrenal angiomyolipomas were often symptomatic, more common in females and in the fifth decades of life. To conclude, adrenal lipomatous tumour is uncommon. They are often benign and non-functional. It is important to recognize the features of this group of lipomatous tumours in the adrenal gland as they are being detected on increasing incidence as a result of the wide-spread use of modern imaging modalities.

MRI findings in intraspinal mature teratoma

AIM

To characterise and evaluate magnetic resonance imaging (MRI) images for their clinical value in diagnosing and assessing intraspinal mature teratoma.

MATERIALS AND METHODS

MRI images obtained from eight patients with a histopathologically verified intraspinal mature teratoma were analysed retrospectively regarding tumour location, size, and margins. Additionally, the signal intensity and enhancement pattern on MRI and other associated malformations were also assessed.

RESULTS

Three cases that contained fatty tissue showed markedly heterogeneous hyperintense signalling on T1-weighted images, and mixed hyperintense and hypointense signalling on T2-weighted images and fat-suppression sequences. All three of those cases showed an irregular peripheral fatty tissue signal, and one case showed additional patches of an interspersed calcification signal. The remaining five cases without fatty tissue displayed heterogeneous hyperintense signalling on T1-weighted images and T2-weighted images, and also on fat-suppression sequences. Four of the five cases showed additional patches of interspersed nodular calcification signals. Contrast-enhanced MRI images showed only slight enhancement (n=3).

CONCLUSIONS

MRI is regarded as the reference standard diagnostic technique to reveal the location of teratomas and the degree of spinal cord involvement. In most cases, MRI provides accurate anatomical and histological information, which is necessary for patients with suspected intraspinal mature teratoma.

[Mediastinal germ cell tumors: anatomopathology, classification, teratomas and malignant tumors]

Mediastinal germ cell tumors are rare tumors. It is classic to divide those tumors into two categories, seminomas and nonseminomatous germ cell tumors: teratomas (mature or immature), embryonal carcinomas, yolk sac tumors, and choriocarcinomas. Each histological sub-type can be associated to another sub-type that realise a so-called mixed germ cell tumor. Diagnosis strategy is currently well codified for malignant mediastinal germ cell tumors. It greatly benefits from tumoral markers (alpha-fetoprotein and beta human chorionic gonadotrophin). For instance, the treatment strategy still raises some specific problems to each histological type. The treatment of seminomatous tumors is standardised--chemotherapy/surgery on residual tumor greater than 3 cm/radiotherapy on viable persistent residual tumors--and provides very satisfying results. As for the nonseminomatous germ cell tumors, the situation is dramatically different. The treatment strategy is less standardised--association of chemotherapy and surgery--and the prognosis is very severe.

[Diagnostic value of multiple tumor marker detection for mature and immature teratoma of the ovary]

BACKGROUND & OBJECTIVE

It is difficult to differentially diagnose mature cystic teratoma (MCT) and immature teratoma (IT) of the ovary before operation. This study was to evaluate the value of multiple tumor marker detection in differential diagnosis of ovarian MCT and IT.

METHODS

Clinical data of 272 patients with ovarian teratoma, diagnosed pathologically and treated at Cancer Center of Sun Yat-Sen University from Jan. 1995 to Dec. 2005, were reviewed. Of the 272 patients, 254 had MCT and 18 had IT. The serum levels of carbohydrate antigen 125 (CA125), CA153, CA199, neuron-specific enolase (NSE), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) in MCT and IT were compared.

RESULTS

Of the 254 patients with MCT, the median age was 30, the mean serum levels of CA125, CA153, CA199, NSE, AFP and CEA were 25.5 x 103 u/L, 11.8 x 103 u/L, 106.6 x 103 u/L, 12.6 microg/L, 2.7 microg/L and 2.5 microg/L. Of the 18 patients with IT, the median age was 23, the mean serum levels of these tumor markers were 140.3 x 103 u/L, 16.8 x 103 u/L, 112.0 x 103 u/L, 18.0 microg/L, 369.5 microg/L and 3.2 microg/L. Both the serum levels and positive rates of CA125, CA153 and AFP were significantly higher in IT than in MCT (P<0.05). When detected alone to differentially diagnose MCT and IT, the specificity of CA125, CA153, AFP were high, and the sensitivity of CA125 was the best (50.0%). The sensitivity was elevated to 71.4% by combined detection of CA125, CA153 and AFP.

CONCLUSION

Combined detection of tumor markers, especially CA125, CA153 and AFP, may be helpful for differential diagnosis of ovarian MCT and IT.

Pathology and molecular biology of teratomas in childhood and adolescence

The biologic behaviour of teratomas depends on various interdependent clinical and epidemiologic variables such as the age at diagnosis, sex, tumor site, histology which all correlate to different cytogenetic and molecular biologic aberrations. Thus, testicular teratomas of infancy are generally benign. Accordingly, prepubertal teratomas show no cytogenetic or molecular genetic aberrations. In contrast, postpubertal testicular teratomas can present as clinically malignant tumors and may show complex cytogenetic aberrations such as the isochromosome 12p, which is pathognomonic of malignant germ cell tumors. Notably, teratomas of both age groups show an at least partial erasure of the genomic imprinting, correlating with their origin from primordial germ cells. The Kiel Pediatric Tumor Registry includes 541 teratoma specimens, and among these, the most frequent tumor sites (in descending order) are: the sacrococcygeal region (33.8 %), the ovaries (31.2 %) and the testes (10.5 %). Rare localizations include the mediastinum, the retroperitoneum, the head and neck region as well as the central nervous system. The WHO classification of germ cell tumors distinguishes mature and immature teratomas as well as teratomas with malignant transformation. In immature teratomas, primitive neuroectodermal structures predominate. According to the grading system (Gonzalez-Crussi, 1982), mature teratomas (G0) are more frequent (54.5 %) than immature teratomas (G1-G3, 45.5 %). Only 7.8 % of all teratomas show the highest grade of immaturity (G3). The frequency of additional microscopic foci of malignant yolk sac tumor correlates with the grade of immaturity. In sacrococcygeal teratomas, the yolk sac tumor microfoci may give rise to a malignant relapse after incomplete resection. The rare teratomas with malignant transformation contain components with "conventional" somatic type malignancy such as leukaemia, carcinoma or sarcoma. Here, molecular genetic analysis has demonstrated the origin of the somatic malignancy from a malignant transformation within the germ cell tumor with retention of the cytogenetic changes characteristic of malignant germ cell tumors.

The Malignant Potential of Teratomas in Infancy and Childhood: The MAKEI Experiences in Non-Testicular Teratoma and Implications for a New Protocol

Since 1982, mature and immature teratomas have been recruited into the MAHO and MAKEI protocols of the German Society for Pediatric Oncology and Hematology (GPOH) for testicular and non-testicular germ cell tumors in order to study the epidemiology and clinical behaviour of teratomas. Patients were registered in the epidemiologic German Childrens Cancer Registry and the GPOH Childrens Tumor Registry for pathological review. Patients with immaturity grade 2 and 3 according to Gonzales-Crussi were eligible for adjuvant chemotherapy. The consecutive protocols MAKEI 83/86/89 have been published previously in detail (Klin Paediatr 1997; 209: 228-234, Med Pediat Oncol 1998; 31: 8-15) and will be compared to the data of MAKEI 96. For this comparison, 274 patients from MAKEI 83/86/89 and 261 patients from MAKEI 96 are evaluable.

RESULTS

1) EFS after complete tumor resection has been estimated to 0.96 +/- 0.01 in both observation periods. 2) Incomplete tumor resection remains the main risk factor for relapse (EFS 0.55 +/- 0.09). 3) The relapse rate declined from 13.9 % in MAKEI 83/86/89 to 9.5 % in MAKEI 96. 4) In MAKEI 83/86/89 four newborns with teratoma died due to perioperative complications and nine children as a result of tumor progression, whereas in MAKEI 96 no newborn died, only one child died from tumor progression, and another child died during long time observation for another reason (meningitis). 5) In accordance to the experience of the MAKEI 83/86/89 studies, no child of the MAKEI 96 study presented with yolk sac tumor at recurrence if adjuvant chemotherapy was administered during first-line treatment because of immaturity. In contrast, more than half of the children with tumor recurrence after watch and wait strategy had yolk sac tumor in addition to teratoma.

Recent Advances in the Pathology and Classification of Ovarian Germ Cell Tumors

In recent years, our knowledge of ovarian germ cell tumors has increased, and their classification has evolved. The introduction of cisplatin-based chemotherapy and the discovery of tumor markers, including alpha-fetoprotein and human chorionic gonadotropin, have dramatically changed the clinical outlook for most of these patients. In this review, recent advances in the classification and pathology of ovarian germ cell tumors are discussed. Where appropriate, comparisons are made with testicular germ cell tumors. The last section of the article discusses the pathogenesis of germ cell tumors. This review will emphasize the articles written in the last 10 years and those that have significantly advanced our knowledge of germ cell tumors in past decades.

Newly defined central nervous system neoplasms

In recent years, numerous new entities or variants of recognized central nervous system tumors have been described in the literature, and the morphologic spectrum of these neoplasms is delineated incompletely. The accurate diagnosis and classification of these lesions is important to ensure that patients receive adequate therapy and prognostic information. The clinicopathologic features and differential diagnosis of 4 new entities, including the chordoid glioma of the third ventricle, cerebellar liponeurocytoma, atypical teratoid/rhabdoid tumor, and papillary glioneuronal tumor, are discussed in this review.

Teratomas of the ovary: a clinico-pathological evaluation of 87 patients from one institution during a 10-year period

AIM

To present the classification and diagnostic problems encountered between teratomas and other ovarian tumors as well as with other benign entities diagnosed and treated in our institution.

METHODS

We analysed retrospectively the clinical and pathological characteristics of 87 teratomas examined in our hospital during the last ten years.

RESULTS

Teratomas constituted 5% of all ovarian tumors. The age range was from 11-69 years old (median: 35). The most frequent symptom was lower abdominal pain in 68% of patients. A pelvic mass was noted in 3% of cases. A pregnancy was present in 3% of patients. In ten cases the tumors were bilateral. Tumor size ranged from 1-16 cm in diameter (median: 7.17 cm). The treatment consisted of cystectomy in 66% of the cases, oophorectomy in 23% or hysterectomy with both adnexa in 11% of cases. Fifty-seven cases presented with a histological diagnosis of mature teratoma, biphasic or triphasic type, three cases with monodermal teratoma, ten cases with ovarian neoplasms of mixed type, 15 cases with epidermal cysts, and two cases with benign cysts. Malignant changes within the teratomas were seen in 5% cases.

CONCLUSION

Teratomas are common ovarian tumors at any age, especially during the reproductive age, with a low rate of complications and malignant transformation. The treatment should be based on patient age, fertility status, tumor size, the cystic or solid nature of the tumor and bilaterality.

Regenerative medicine: stem cells and the science of monstrosity

The nineteenth century science of teratology concerned itself with the study of malformations or "monstrosities", as they were then called. The first major contribution to the field was the work of Isidore Geoffrey Saint-Hilaire, Historie Generale et Particuliere des Anomalies de l'Organisation chez l'Homme et les Animaux, published in 1832, whose classifications formed the basis for the later experimental science of teratogeny, the art of reproducing monstrosities in animal embryos. In this article, I will argue that recent developments in the field of regenerative medicine can be situated in the tradition of teratological and teratogenic studies dating back to the nineteenth century. In particular, I will be interested in the historical link between studies in teratogenesis (the artificial production of teratomas) and stem cell research. Recent advances in stem cell research, I will suggest, return us to the questions that animated nineteenth century investigations into the nature of the monstrous or the anomalous. In the process, our most intuitive conceptions of "life itself" are undergoing a profound transformation.

The future of therapy for nonseminomatous germ cell tumors

This article has reviewed recent advances in understanding the molecular mechanisms of germ cell transformation, germ cell tumor differentiation, and germ cell tumor chemotherapy sensitivity and resistance. Future developments should include the following: The use of high-throughput techniques to assess tumor biology and evaluate new markers will allow more sophisticated assessment of prognosis. Future therapy will use oligonucleotide chips, perhaps specific to germ cell tumors or gene products associated with drug resistance, to assign treatment (radiation, RPLND, chemotherapy). The pathways associated with metastases and resistance will either replace or amplify the current risk algorithms and the clinician's ability to select therapy. The same high-throughput techniques will identify critical molecules and pathways, providing new specific treatment targets. Cell cycle-specific targets are an ideal focus of study, because genes abrogating normal cell cycle control and promoting germ cell tumorigenesis are increasingly identified. In germ cell tumors, CCND2 and KIT are open to study. Molecular and genetic markers of differentiation are additional resistance markers and should be a focus of study. In this context, the treatment of malignant transformation and the prediction of teratoma at metastatic sites will take on a greater importance. Over the past 2 decades, the treatment of germ cell tumors has become well-defined. Further improvement requires that investigators find new markers corresponding to tumor phenotype. This achievement will prevent unnecessary treatment in patients destined to have a favorable outcome, and will target biologically unfavorable or resistant disease for new therapy developed specifically to target the molecular or genetic defects that disrupt normal cell cycle control.

Various findings in surgically treated epilepsy patients with dysembryoplastic neuroepithelial tumors in comparison with those of patients with other low-grade brain tumors and other neuronal migration disorders

PURPOSE

To determine whether dysembryoplastic neuroepithelial tumors (DNTs) that belong to the neuronal migration disorders (NMDs) are to be classified with them or with "other low-grade brain tumors" regarding several etiologic, clinical, magnetic resonance imaging (MRI), and EEG findings.

METHODS

These findings of 21 DNT patients were compared with those of 13 consecutive patients with other low-grade brain tumors and 41 NMD patients.

RESULTS

The result is absolutely clear: nearly all findings in DNT patients (complications during pregnancy, birth, the newborn period and the postnatal period, age at first seizure, epileptic syndrome, seizure type, febrile seizures, retarded milestones, intellectual and neurologic deficits, MRI, interictal and ictal EEG findings) being similar or in agreement with those of other low-grade brain tumors, not with those of other NMDs.

CONCLUSIONS

Regarding various clinical features including surgery outcome, MRI, and EEG findings, DNTs should be classified with the other low-grade brain tumors, rather than with NMDs.

Apoptosis and proliferative activity in mature and immature teratomas of the mediastinum

BACKGROUND

Mediastinal teratomas are the most frequent mediastinal germ cell tumor. Whereas mature teratomas are benign tumors, immature teratomas are malignant. The purpose of this study was to find characteristics that could be used to distinguish between the growth and prognosis of the two teratoma types.

METHODS

Twenty-four mediastinal teratomas (18 mature and 6 immature) were examined for apoptosis by 3'-end labeling of DNA and stained immunohistochemically for proliferating cell nuclear antigen, Bcl-2, Bax, p53 protein, and alpha-fetoprotein (AFP) expression in formalin fixed, paraffin embedded specimens.

RESULTS

AFP was expressed in both immature teratomas and mature teratomas. Whereas p53 protein was expressed by most teratomas, p53 gene mutation was observed in only one patient with an immature teratoma in which the same mutation occurred in all tumor tissue components tested. Bax protein expression was relatively diffuse in mature teratomas but was focally expressed in immature teratomas. Bcl-2 protein was expressed focally in both mature and immature teratomas. Although the proliferative index was significantly higher in immature teratomas compared with mature teratomas (P < 0.001), the apoptotic index (AI) was significantly higher in mature teratomas compared with immature teratomas (P < 0.05). All patients except one in this study remain alive and disease free after undergoing tumor resection.

CONCLUSIONS

The relatively high AI in mature teratomas may be due to the overexpression of the p53 protein. In contrast, immature teratomas exhibited higher proliferative activity and lower rates of apoptosis, which may explain the more aggressive behavior of these tumors. However, patients with immature mediastinal teratomas have a good prognosis if the tumor is resected completely after chemotherapy.

Eustachian tube teratoma and its terminological correctness

Teratomas are germ cell tumours usually found in the young and are characteristically composed of tissue foreign to the place where they arise. Two teratomas of the middle ear were first described in 1866 and since then, and to the best of our knowledge, 19 additional cases have been reported in the literature under different terms such as hairy congenital polyps, epidermoid cysts, dermoid cysts, hamartoma, cutaneous teratoma and teratomas. The difficulty in classifying germ cell tumours may explain the different terminologies encountered in the literature. The authors describe a case of teratoma of the eustachian tube presenting as a mass in the middle and external ear of a 10-week-old girl. Using this case, a review of the literature is performed in light of the new classification of germ cell tumours proposed by the World Health Organization (WHO). It is of note that most of the teratomas that present in the middle ear arise from, or involve, the eustachian tube.

Intracavernous teratoma in a school-aged child

An eight-year-old boy presented with left eye pain, photophobia, proptosis, third nerve paresis and decreased visual acuity. Magnetic resonance imaging revealed a nonenhancing mass filling the cavernous sinus. Using an extradural fronto-orbitozygomatic approach, the cavernous sinus was approached laterally, and a teratoma was removed from within the cavernous sinus. This is the first case of a truly intracavernous teratoma in a child and the fourth case of a teratoma reported in the cavernous sinus region overall. This report outlines the diagnosis and treatment of this unusual cavernous sinus tumor.

Primary germ cell tumors of the mediastinum: I. Analysis of 322 cases with special emphasis on teratomatous lesions and a proposal for histopathologic classification and clinical staging

BACKGROUND

Primary germ cell tumors of the mediastinum are unusual neoplasms with histopathologic features that are similar to those of germ cell tumors in the gonads. However, their clinical features, behavior, and spectrum of pathologic features in the mediastinum have not yet been fully defined.

METHODS

The clinical and pathologic features of 322 cases of primary mediastinal germ cell tumors were reviewed, with special emphasis on teratomatous lesions. The tumors were divided into groups according to their histologic features and correlated with their order of frequency, patient gender and age distribution, and morphologic features. A clinical staging scheme based on the extent and location of the lesions was devised.

RESULTS

The overwhelming majority of patients were men (320); only 2 were women (both had teratomatous lesions with additional malignant components). The patients' ages ranged from 1 to 79 years (mean, 40 years). Histologically, all types of germ cell tumors were represented, including 138 teratomas (87 mature teratomas, 6 immature teratomas, and 45 teratomas with additional malignant components); 120 seminomas; 52 nonseminomatous, nonteratomatous germ cell tumors (38 yolk sac tumors, 6 embryonal carcinomas, and 8 choriocarcinomas); and 12 combined germ cell tumors without teratomatous components. The teratomatous lesions with additional malignant components were further separated into subtypes based on the histologic types of their malignant components, i.e., epithelial, mesenchymal, etc. Clinical staging was possible in 242 cases, with 191 cases (79%) in Stage I, 4 cases (1.6%) in Stage II, and 47 cases (19.4%) in Stage III. In each group, the clinical staging correlated well with the clinical outcome for the majority of patients.

CONCLUSIONS

The results of this study showed that mediastinal germ cell tumors have demographic and histopathologic distributions similar to those of tumors occurring in the male gonads, with teratomatous and seminomatous lesions being the most common. Among the nonseminomatous germ cell tumors in this study, the yolk sac tumors appeared to occur the most frequently (the ratio of yolk sac tumor occurrence to embryonal carcinoma occurrence was 6.1:1). In addition, the subclassification of teratomas with additional malignant components based on the histologic types of malignancies may lead to more therapy choices for patients. At the same time, the use of a clinical staging scheme may be of value in predicting clinical outcome and planning therapy.

Extracranial non-testicular teratoma in childhood and adolescence: introduction of a risk score for stratification of therapy

PATIENTS AND METHODS

According to previous literature incomplete tumor resection, coccygeal or ovarian primary site and immaturity are known risk factors for relapse in teratoma. To establish a risk score points are allocated for resection, primary site and histology in the following manner and added: incomplete resection 4 points, primary site coccyx 3 points, ovary 2 points, other site 1 point, histological grading 0-3 points. This score system is evaluated on 270 extracranial non-testicular teratoma cases collected between 1982 and 1995 in the MAKEI cooperative treatment protocols of the German Society of Pediatric Oncology and Hematology. Treatment was resection alone (230 patients) or resection followed by postoperative adjuvant chemotherapy (40 patients).

RESULTS

Patients treated with surgery alone: 28/230 (12%) patients relapsed, 14/230 (6%) patients showed highly malignant histology (mostly yolk sac tumor) in relapse. Mortality in case of relapse was 6/28 (21%). Patients scoring > or = 6 points (n = 45) had a relapse rate of 21/45 (47%) resulting in a 23%-mortality (5/21). Patients scoring < 6 points (n = 185) had a 4%-relapse risk (8/185) resulting in 13%-mortality (1/8) (p < 0.01). Patients treated with surgery and adjuvant chemotherapy: 7/40 patients (18%) suffered a relapse, none of them showing malignant histology. Mortality rate in case of relapse was 3/7 (43%). Patients scoring > or = 6 points initially treated with adjuvant chemotherapy (n = 18) had a relapse rate of 7/18 (39%), compared to patients scoring < 6 points (n = 22), in whom no relapses occurred (p < 0.01). There were no highly malignant relapses in the group treated with adjuvant chemotherapy. Regardless of the scored points the difference in highly malignant relapse histology comparing the group treated with surgery and adjuvant chemotherapy to the group treated with surgery was statistically significant (p = 0.02).

CONCLUSION

The risk score system marks a high risk group including 63/270 (23%) of all evaluated extracranial non-testicular teratoma cases (scoring > or = 6 points). In this group 28/35 (80%) of relapses and 8/9 (89%) of tumor deaths occurred. For this high risk group a randomized trial will be suggested to evaluate the effect of adjuvant chemotherapy on the rate of malignant relapses. It should also be investigated, if adjuvant chemotherapy will influence relapse rate and mortality.

Teratomas in infancy and childhood at Tygerberg Hospital, South Africa, 1973 to 1992

OBJECTIVES

To document the childhood teratomas at Tygerberg Hospital and compare the profile with other African series.

DESIGN

Retrospective review of the clinicopathologic features of 43 cases of childhood teratomas. Tumors were classified according to the World Health Organization criteria for germ cell tumors.

SETTING

Tygerberg Hospital, University of Stellenbosch, Cape Town, South Africa.

RESULTS

There were 26 mature, 15 immature, and 2 malignant teratomas. The most common sites were the ovaries and the sacrococcygeal region. Testicular teratomas were absent. The female-to-male ratio for black patients was 5.5:1. There was a peak age incidence in the first 4 years of life, with sacrococcygeal teratomas predominating. A second, smaller peak between 12 and 15 years was seen owing to ovarian teratomas. Immature teratomas presented at an earlier age than mature teratomas. The majority of ovarian teratomas occurred in patients of mixed race, whereas the extragonadal teratomas were distributed more evenly among the race groups. In black patients and patients of mixed race mature teratomas predominated, whereas in white patients immature teratomas were most common.

CONCLUSIONS

The increased occurrence of teratomas among female patients, the large number of ovarian teratomas, the absence of testicular teratomas, and the low incidence of malignant teratomas correspond to the observations of other African series. Certain differences are apparent among the three race groups, namely, a high ratio of female-to-male patients in the black group, a predominance of ovarian teratomas in the mixed-race and black groups, and a predominance of extragonadal and immature teratomas in the white group.

"Polyphenotypic" tumors in the central nervous system: problems in nosology and classification

In recent years, there is increasing recognition of polyphenotypic high-grade malignancies in the non-central nervous system (CNS) tumor literature. Some of these tumors have been regarded as variants of primitive neuroectodermal tumor (PNET) or as extrarenal malignant rhabdoid tumors (MRTs). This report concerns two posterior fossa neoplasms, both of which displayed a "polyphenotypic" expression of neural, epithelial, myogenic, and glial markers, including synaptophysin, neurofilament, vimentin, glial fibrillary acidic protein, S-100, neuron-specific enolase, desmin, S antigen, MIC2, cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen. One tumor showed complex intercellular junctions, cytoplasmic intermediate filaments, well-developed rough and smooth endoplasmic reticulum and Golgi apparatus, cilia, and neurosecretory granules. The other neoplasm showed pools of glycogen, desmosomes, and tonofilaments. The histological and ultrastructural appearances were inconsistent with glioma, PNET, meningioma, ependymoma, choroid plexus carcinoma, sarcoma, germ cell tumor, and other tumors in the World Health Organization classification. Although the polyphenotype raises the issue that these may represent variants of MRT or the atypical teratoid-rhabdoid tumor, the morphologic findings in the two cases were very dissimilar. Our two cases underscore the problems in nosology and classification of polyphenotypic tumors of the CNS. This is particularly significant, as therapeutic protocols for PNET, MRT, and non-CNS polyphenotypic tumors are different. We review the literature on polyphenotypic tumors and reiterate the difficulties in precise classification of these complex tumors.

Color Doppler aided prenatal diagnosis of a type 1 cystic sacrococcygeal teratoma simulating a meningomyelocele

Type 1 cystic sacrococcygeal teratomas, usually associated with good outcome following neonatal resection, must be differentiated at the time of prenatal diagnosis from sonographically similar meningomyeloceles, which carry a grave prognosis. We present an unusual case in which color Doppler imaging assisted correct midtrimester prenatal diagnosis of a large type 1 cystic sacrococcygeal teratoma closely simulating a meningomyelocele.

[Teratoma of the middle ear. Apropos of 4 new cases]

Teratomas are benign hereditary tumors which are exceptionally located in the middle ear. We observed 4 cases and underline the difficulty in preoperative differential diagnosis with hereditary cholesteatoma using CT scan and emphasize the potential of MRI. Generally, diagnosis can only be confirmed by the peroperative macroscopic aspect of the tumor and after pathology examination (multi-tissue teratoma). The difficulty in excising the tumor is directly related to the degree of the subsequent deformation of the middle ear. Ossiculoplasty was required in 2 of our 4 cases. Finally, rare recurrence requires follow-up in these young patients.

[Familial sacrococcygeal teratoma]

Familial sacrococcygeal teratomas are very rare. Up to now, only 8 kindreds (31 patients, including 1 Japanese kindreds) have been reported. All cases are Altman type IV variety. The tumor complex consists of a presacral teratoma and sacrococcygeal bony anomalies. The most common symptoms are constipation and anorectal stenosis. Two patients died. One died of meningitis following removal of a large benign tumor because of communication with a spinal arachinoid space. The other, with a large benign tumor, died as a result of malignant change, 10 years later after the first operation. The incidence of malignant change of familiar sacrococcygeal teratoma is rare in comparison with that of non-familiar sacrococcygeal teratomas.

Intracranial lipomas with teratomatous elements

We report two cases of patients with intracranial tumors that share features with lipomas and teratomas. Although rare reports of lipomas with "hypertrophic nerves" and "teratoid tumors" have been recorded, these two cases are unusual because they contain mature neuroectoderm (choroid plexus, peripheral nerve) and mesoderm (skeletal muscle). The findings are discussed and modern classification schemes are presented. We believe that the cases are examples of a transition between lipoma and teratoma.

[Antenatal prognostic factors in sacrococcygeal teratomas]

The authors report 5 cases of sacrococcygeal teratoma, 4 of which were diagnosed by routine ultrasonography. In view of the poor prognosis of sacrococcygeal teratomas discovered antenatally, certain ultrasonographic severity criteria have been defined. The following are felt to be relevant in this light of present knowledge: a tumour size greater than the biparietal diameter of the fetus at the time of diagnosis; rapid tumour growth. This latter parameter summarises in itself the criteria taken into account in the past: placentomegaly, hydramnios, anasarca. Colour coded Doppler should make it possible in the future to identify a group which might benefit from treatment in utero.

Time trends in accuracy of classification of testicular tumours, with clinical and epidemiological implications

Initial classifications of 1009 testicular tumours were reviewed as part of a population based survey of all testicular neoplasms in Victoria, Australia, between 1950 and 1978. All reviews were made by one of two pathologists at the Peter MacCallum Cancer Institute, using the system of the British Testicular Tumour Panel. Accuracy of diagnosis varied markedly over the time period and with pathological category. Seven cases were initially designated malignancies but were determined to be non-malignant conditions upon review. In each decade, review reduced the proportion of seminomas and increased the proportion of non-seminoma germ cell tumours (NSGCT) and non germ cell tumours. Reclassification resulted in changed age specific incidences of seminoma and NSGCT, most noticeably in 1950-59. Trends in age standardised incidence of seminoma and NSGCT were not affected by reclassification although the values were. The trend in age standardised incidence of non germ cell tumours was affected by reclassification. The implications of the changes in classification for epidemiological studies and clinical management are discussed.

Cervical teratomas: an analysis. Literature review and proposed classification

Cervical teratomas are uncommon lesions usually diagnosed at birth but occasionally reported in older children and adults. During a 58-year span, nine cervical teratomas were identified at our institution (four previously reported): three stillborns with giant tumors; five live newborns; and one adult with a malignant tumor. Of the five newborns, two prematures died within one hour of birth. Of the three survivors, 2 had respiratory distress at birth. These infants were treated with early excision and are well at 7, 6, and 2 years of age. The last patient also had cystic fibrosis. The adult died of metastatic disease 8 months after resection. A literature review disclosed 212 cases in addition to the five reported here. Previous attempts at categorizing cervical teratomas have failed to address clinical patterns and have little prognostic value. We propose a classification based on birth status, age at diagnosis, and the presence or absence of respiratory distress. Group I--stillborn and moribund live newborns: number (N), 27; mortality (M), 100%. Group II--newborn with respiratory distress: N, 99; M, 43.4%. Group III--newborn without respiratory distress: N, 37; M, 2.7%. Group IV--children age 1 month to 18 years: N, 31; M, 3.2%. Group V--adults: N, 23; M, 43.5%. Twenty-six patients in group II and one in group III died without excision of the mass. Seventy-three patients in group II, 36 in group III, and 31 in group IV had extirpation of the tumor. Operative mortality was 11%, 0%, and 3.2%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Classification of human ovarian tumors

Most human ovarian tumors are classified into one of several categories based on presumed histogenesis and direction of differentiation. Separate categories are reserved for neoplasms composed of cells of several origins and for nonneoplastic disorders that simulate neoplasms. Using the World Health Organization Histologic Classification of Ovarian Tumors, histologic features for common and rare human ovarian tumors are described and illustrated.

Dysontogenetic brain tumours--proposal for an improved classification

The International World Health Organisation (WHO) classification of central nervous system tumours does not give an extensive classification of germ cell tumours and other malformative tumours and tumour-like lesions. In the same way, no consistent classification of dysontogenetic brain tumours can be found in the classical handbooks. For an eventual new edition of the WHO classification, it is proposed to reconsider and improve the classification of these tumours, based on their ontogenetic relations.

Peripheral and central primitive neuroectodermal tumors. A nosologic concept seeking a consensus

The term primitive neuroectodermal tumor is widely used in the literature for a group of small, round-cell tumors in the central and sympathetic nervous systems and soft tissues as well as a specific diagnostic term for individual neoplasms; however, the contention that these various clinicopathologic entities (neuroblastoma, medulloblastoma, and peripheral neuroepithelioma) are histogenetically related is an unproved hypothesis. Morphologic, cytogenetic, immunohistochemical, biochemical, and in vitro studies have established phenotypic similarities among these putatively related neoplasms whether they originate in the brain, adrenal gland, or soft tissues. Because one tumor resembles another in terms of its phenotypic expression, that does not necessarily imply a common histogenesis. This point has been made by previous investigators. The purpose of this review is to evaluate and discuss the present status of our understanding and some of the controversial aspects of this enigmatic category of neoplasms, mainly occurring in children, known as the primitive neuroectodermal tumors.

Primary peritoneal, omental, and mesenteric tumors in childhood

Of 21 primary peritoneal, omental, and mesenteric tumors, 14 were cysts and seven were solid. Most of the cysts were omental-mesenteric lymphangiomas; the sole exception was a cystic mesothelioma in a newborn. The solid tumors included three multicentric hamartomas, three sarcomas of undetermined histogenesis, and one immature teratoma. Since cystic lymphangiomas carry a good prognosis following surgical excision, they must be distinguished from cysts of mesothelial origin. Solid hamartomas may simulate malignant tumors because of multicentricity and immature tissue composition. Although peritoneal sarcomas of undetermined histogenesis are apt to be large, composed of primitive cells, and disposed to the development of implants, current treatment modalities may control the disease. One of three treated patients survived for 8 years. A child with a solid immature teratoma without a malignant germ-cell component remains free of disease 5 years after diagnosis. Our review, which represents the combined experience of two children's hospitals over several decades, did not include tumors such as malignant mesothelioma, lipoma, liposarcoma, leiomyoma, mesenchymoma, fibromatosis, and other neoplasms, which may rarely arise in the peritoneum, omentum, and mesentery of children.

Systemic staging of supratentorial extra-axial brain tumors in children. Craniopharyngiomas, atypical teratoma and teratoid tumors of the suprasellar region (germinomas), and intracranial teratomas

A staging system has been proposed for the following tumors: craniopharyngiomas, germinomas, and intracranial teratomas. Various aspects of the specific pathologic and growth characteristics of the tumor determines such categorization and subclassification of the tumors. A brief analysis of the clinical aspects in reference to classification is presented. The suggested systems will need to be tested in clinical studies to determine their validity.

Sonographic demonstration of fetal sacrococcygeal teratoma

Six cases of sonographically diagnosed fetal sacrococcygeal teratoma (SCT) are presented and illustrate the variable features of fetal SCT. The sonographic findings assisted the parents and perinatal team in making decisions, and in two of the cases the children survived after elective Cesarean section and prompt neonatal resection of the tumors. None of the patients showed signs of malignant degeneration of the teratoma or metastases. Fetal SCT no longer should be considered a uniformly fatal condition. The literature on sacrococcygeal teratoma detected after birth indicates that the mortality rate is correlated with the degree of extension of the tumor. Therefore, the classification of sonographically diagnosed fetal SCT according to its size and position is important for decisions regarding pregnancy management.

Teratomas of the head and neck in childhood

Teratomas are tumors consisting of tissue arising from all three embryonic germ layers. Their occurrence in the head and neck region is rare. Three patients with this lesion are presented. Although exhibiting progressive uncoordinated growth, histologic evidence of malignancy in the head and neck form of this tumor is distinctly uncommon. Mortality associated with teratomas is most often secondary to respiratory compromise. Complete surgical extirpation is the treatment of choice to lower mortality and recurrences. The use of fine needle aspiration in the management of neck masses in children is discussed.

Primitive neuroectodermal tumor (immature teratoma) of testis

The malignant neuroectodermal tumor is a recently described distinctive form of monodermal teratoma of the ovary. The first known example of this rare tumor occurring in the testis is reported.

Diffuse embryoma of the testis. A distinctive form of mixed germ cell tumor

Two testicular tumors characterized by a diffuse, orderly arrangement of embryonal, yolk sac, and trophoblastic elements are described as examples of a newly recognized form of mixed germ cell neoplasia. In one case, ribbons of embryonal carcinoma and yolk sac tumor wound around one another to create a distinctive necklace pattern. In the second case, differentiation of the yolk sac component was more advanced with the formation of numerous clusters of cells resembling hepatocytes. Tumors with these patterns are appropriately designated diffuse embryomas to distinguish them from polyembryomas and other forms of malignant mixed germ cell tumor.

Gonadal and extragonadal germ cell neoplasia of childhood

Germ cell tumors in children are characterized by diverse clinical, pathologic, and prognostic features. For this reason, it is difficult to generalize about the behavior of these tumors; cases must be evaluated individually, with consideration for the age of the patient at diagnosis, the anatomic site of the tumor, and its histologic appearance. Experimental models and cytogenetic studies of teratomatous development have contributed to our basic understanding of the biology of differentiation and tumorigenesis.

[Benign stomach tumors. Our personal cases]

After a review of the anatomopathological aspects of benign stomach tumours, 16 clinical cases are presented with an analysis of the more significant clinical and diagnostic features and the treatment employed.