Growing teratoma syndrome in intracranial non-germinomatous germ cell tumors (iNGGCTs): a risk for secondary malignant transformation—a report of two cases

A case series and literature review on 98 pediatric patients of germ cell tumor developing growing teratoma syndrome

INTRODUCTION

Malignant germ cell tumors (MGCTs) can develop either extracranially or intracranially. Growing teratoma syndrome (GTS) may develop in these patients following chemotherapy. Reports on the clinical characteristics and outcomes of GTS in children with MGCTs are limited.

METHODS

We retrospectively collected the data, including the clinical characteristics and outcomes of five patients in our series and 93 pediatric patients selected through a literature review of MGCTs. This study aimed to analyze survival outcomes and risk factors for subsequent events in pediatric patients with MGCTs developing GTS.

RESULTS

The sex ratio was 1.09 (male/female). In total, 52 patients (53.1%) had intracranial MGCTs. Compared with patients with extracranial GCTs, those with intracranial GCTs were younger, predominantly boys, had shorter intervals between MGCT and GTS, and had GTS mostly occurring over the initial site (all p < 0.001). Ninety-five patients (96.9%) were alive. However, GTS recurrence (n = 14), GTS progression (n = 9), and MGCT recurrence (n = 19) caused a substantial decrease in event-free survival (EFS). Multivariate analyses showed that the only significant risk factors for these events were incomplete GTS resection and different locations of GCT and GTS. Patients without any risk had a 5-year EFS of 78.8% ± 7.8%, whereas those with either risk had 41.7% ± 10.2% (p < 0.001).

CONCLUSION

For patients with high-risk features, every effort should be made to closely monitor, completely remove, and pathologically prove any newly developed mass to guide relevant treatment. Further studies incorporating the risk factors into treatment strategies may be required to optimize adjuvant therapy.

Radiological pseudoprogression post-radiotherapy in a child with pineal germ cell tumour

Little is known about pseudoprogression in brain tumours other than gliomas. A 9-year-old male child with a pineal teratoma/germinoma underwent surgical resection followed by adjuvant chemo-radiotherapy. The magnetic resonance imaging scan 4 months post-radiotherapy showed a contrast-enhancing lesion within the surgical cavity suspicious of recurrence. These radiological findings subsequently resolved without any specific intervention. The child continues in remission 2 years post-treatment. This case illustrates the occurrence of pseudoprogression post-radiotherapy in intracranial GCT and highlights an unmet need for greater implementation of functional imaging techniques in paediatric neuro-oncology to avoid undue discontinuation of effective treatments or inappropriate enrolment in clinical trials.

Primary and Recurrent Growing Teratoma Syndrome in Central Nervous System Nongerminomatous Germ Cell Tumors: Case Series and Review of the Literature

BACKGROUND

The term "growing teratoma syndrome (GTS)" has been used as follows: patients with germ cell tumor (GCT) who present with enlarging original/metastatic masses during or after appropriate systemic chemotherapy despite normalized serum markers. In other words, the definition of the term GTS is not fully established. We analyzed and reviewed our case series regarding GTS that developed after the treatment of central nervous system (CNS) nongerminoatous germ cell tumors (NGGCTs).

METHODS

Our institutional review board approved this retrospective study. Between 2003 and 2018, we treated 16 patients (16 males; age ranging from 5.4 to 51.9 years, median 13.8) with CNS-NGGCT at our institution. We reviewed those patients and also reviewed the literature about GTS of CNS. We defined primary GTS (p-GTS) as the enlargement of cyst size and/or solid tumor occurred during treatment in the absence of marker elevation, and recurrent GTS (r-GTS) as the enlargement of teratoma after complete response of initial tumors.

RESULTS

Among 16 patients with CNS-NGGCT, we surgically confirmed mature/immature teratoma components in 15 patients. Two patients underwent surgical removal of tumor before neoadjuvant therapy, and among the rest 14 patients, 6 developed p-GTS, and 2 patients underwent salvage surgery during chemo-/chemoradiotherapy. Those with histologic diagnosis of immature teratoma during salvage surgery had a shorter interval from the initiation of chemoradiotherapy compared with mature teratoma (P < 0.05). One patient developed r-GTS. In the literature review, most of the p-GTS consisted of enlargement with the multicystic component. Histologic diagnosis of immature teratoma during salvage surgery was observed in earlier stages of chemoradiotherapy (P < 0.05, log-rank test). Previous history of p-GTS might be a risk factor of r-GTS.

CONCLUSIONS

The incidence of p-GTS, enlargement of the cystic component during treatment, is not rare. Physicians need to be aware of this important phenomenon.

Pathological transition as the arising mechanism for drug resistance in lung cancer

Despite the tremendous efforts for improving therapeutics of lung cancer patients, its prognosis remains disappointing. This can be largely attributed to the lack of comprehensive understanding of drug resistance leading to insufficient development of effective therapeutics in clinic. Based on the current progresses of lung cancer research, we classify drug resistance mechanisms into three different levels: molecular, cellular and pathological level. All these three levels have significantly contributed to the acquisition and evolution of drug resistance in clinic. Our understanding on drug resistance mechanisms has begun to change the way of clinical practice and improve patient prognosis. In this review, we focus on discussing the pathological changes linking to drug resistance as this has been largely overlooked in the past decades.

Development of angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy

Herein, we report a case of an angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy. A 26-year-old man presented with a giant anterior mediastinal mass, which was diagnosed as a non-seminomatous germ cell tumor. The patient was administered three cycles of chemotherapy (bleomycin, etoposide, and cisplatin), but the mass grew despite normalization of tumor markers. Massive bleeding during thoracic surgery resulted in incomplete resection, and the mass was clinically and pathologically diagnosed as growing teratoma syndrome (only mature teratoma). The residual mass continued to grow, and complete resection was subsequently achieved after a detailed analysis of its vascular anatomy using angiography. The final pathological findings revealed angiosarcoma, which indicated a rare somatic type of mediastinal non-seminomatous germ cell tumor.

Central Nervous System Germ Cell Tumors: A Review of the Literature

Central nervous system germ cell tumors are rare intracranial tumors that mainly occur in pediatrics with substantial variation in the incidence among different regions and genders. Histologically, central nervous system germ cell tumors can be divided into germinomas and nongerminomatous germ cell tumors. The molecular pathology of central nervous system germ cell tumors, particularly germinomas, is mainly based on the presence of isochromosome 12p, gain-of-function of the KIT gene, and a globally low DNA methylation profile. Diagnoses and differential diagnoses are conducted through imaging, tumor marker detection, surgical biopsy, and cerebrospinal fluid cytology. Germinomas are often treated via whole-ventricular radiotherapy or neoadjuvant chemotherapy combined with reduced-dose whole-ventricular radiotherapy, whereas nongerminomatous germ cell tumors are mainly treated with chemotherapy, surgical resection, and radiotherapy (individually or in combination), depending on tumor composition. Because the main population of patients is pediatric, extending overall survival and reducing treatment side effects should be the main goals of future studies.

Update on molecular findings in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumour in children and adolescents. Histologically RMS resembles developing fetal striated skeletal muscle. RMS is stratified into different histological subtypes which appear to influence management plans and patient outcome. Importantly, molecular classification of RMS seems to more accurately capture the true biology and clinical course and prognosis of RMS to guide therapeutic decisions. The identification of PAX-FOXO1 fusion status in RMS is one of the most important updates in the risk stratification of RMS. There are several genes close to PAX that are frequently altered including the RAS family, FGFR4, PIK3CA, CTNNB1, FBXW7, and BCOR. As with most paediatric blue round cell tumours and sarcomas, chemotherapy is the key regimen for RMS therapy. Currently there are no direct inhibitors against PAX-FOXO1 fusion oncoproteins and targeting epigenetic cofactors is limited to clinical trials. Failure of therapy in RMS is usually related to drug resistance and metastatic disease. Through this review we have highlighted most of the molecular aspects in RMS and have attempted to correlate with RMS classification, treatment and prognosis.

Rhabdomyosarcoma: Advances in Molecular and Cellular Biology

Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in childhood and adolescence. The two major histological subtypes of RMS are alveolar RMS, driven by the fusion protein PAX3-FKHR or PAX7-FKHR, and embryonic RMS, which is usually genetically heterogeneous. The prognosis of RMS has improved in the past several decades due to multidisciplinary care. However, in recent years, the treatment of patients with metastatic or refractory RMS has reached a plateau. Thus, to improve the survival rate of RMS patients and their overall well-being, further understanding of the molecular and cellular biology of RMS and identification of novel therapeutic targets are imperative. In this review, we describe the most recent discoveries in the molecular and cellular biology of RMS, including alterations in oncogenic pathways, miRNA (miR), in vivo models, stem cells, and important signal transduction cascades implicated in the development and progression of RMS. Furthermore, we discuss novel potential targeted therapies that may improve the current treatment of RMS.

PD0332991 (palbociclib) for treatment of pediatric intracranial growing teratoma syndrome

Growing teratoma syndrome is characterized by growth of mature teratoma elements of a mixed germ cell tumor despite resolution of immature/malignant elements with administration of chemotherapy. Surgical resection is the only known cure for growing teratoma syndrome but in the brain, complete resection may be impossible. In these instances, mature teratoma, although histologically benign, may be fatal. In this report, we present the case of a child with a large, rapidly growing, unresectable pineal region growing teratoma. PD0332991 was administered with stabilization of the solid, enhancing components of the mass. Minimal adverse effects were noted.