Occurrence of malignant non-germ cell components in primary mediastinal germ cell tumours

Neutrophil-to-lymphocyte ratio in primary mediastinal germ cell tumors: A retrospective analysis of >20 years single institution experience

OBJECTIVES

To obtain information on outcome stratified by histology, extent and primary treatment patients' data with primary malignant mediastinal germ cell tumors treated between 1998 and 2018 were retrospectively analyzed.

METHODS

The primary treatment for localized malignant mediastinal germ cell tumors was neoadjuvant bleomycin + etoposid + cisplatin (BEP) ± surgery (n = 22); or surgery ± adjuvant BEP (n = 16). For disseminated disease (n = 21) first line BEP ± second line chemotherapy were administered. For nonseminomas (NS) the NLR at start of BEP was analyzed in relation to disease-free survival (DFS), progression-free survival (PFS), and overall survival (OS).

RESULTS

After neoadjuvant treatment the 5-year DFS was 100% for seminomas (S), and 63.4% for NS. The 5-year OS was 100% for S, and 76.9% for NS. The 5-year DFS and OS after surgery ± BEP for S was 72.9% and 100%, for NS was 75% and 87.5%, respectively. The 5-year PFS and OS of metastatic patients for S was 60% and 80%, while the median PFS and OS of NS were 5.7 and 11.1 months, respectively. Objective response (P = 0.006) and low NLR (P = 0.043) were independent prognostic markers of longer OS.

CONCLUSIONS

We confirmed the good outcome of BEP-treated S, while NS had poorer prognosis. Previously published prognostic models for NS were validated. Based on NLR and response a new prognostic model was developed.

Germ Cell Tumors With Sarcomatous Components

The clinicopathologic features of 46 patients with germ cell tumors with sarcomatous components (GCTSC) involving either the primary site or their metastases were studied. There were 43 men and 3 women aged 17 to 74 years. Twenty-three tumors arose in the mediastinum, 2 in the retroperitoneum, and 21 in the gonads. The germ cell component consisted of pure mature or immature teratoma (23 cases), teratoma mixed with other seminomatous or nonseminomatous components (17), pure seminoma (2), intratubular germ cell neoplasia (1), and yolk sac tumor (1). The SC included embryonal rhabdomyosarcoma (29), angiosarcoma (6), leiomyosarcoma (4), undifferentiated sarcoma (3), myxoid liposarcoma (1), malignant peripheral nerve sheath tumor (1), malignant "triton" tumor (1), and epithelioid hemangioendothelioma (1). Immunohistochemical studies were carried out in 34 cases with appropriate results supporting the diagnoses. Metastases containing both GCT and SC were observed in 6 cases, metastases of SC alone in 4, and metastases containing only GCT elements in 3. All patients were treated by cisplatinum-based chemotherapy plus other agents followed by surgery. Clinical follow-up was available in 40 patients (1 to 96 mo; mean=24 mo). Thirty-two of 40 patients either died of tumor (25/40; 62.5%) or were alive with advanced, progressive disease (7/40; 17.5%), and only 8/40 (20%) were alive and free of disease between 5 to 40 months (mean=18 mo). Comparison of these patients with an age-matched and stage-matched control group of patients with GCT without SC showed statistically significant differences in survival between the 2 cohorts (P <or=0.001). On the basis of our findings, the presence of SC appears to represent a poor prognostic sign for GCTs of gonadal and extragonadal origin.

Malignant ganglioneuroma arising from mediastinal mixed germ cell tumor

Mixed germ cell tumors with non-germ cell malignant components rarely occur in the anterior mediastinum. We report a case of a 34-year-old man who presented with an anterior mediastinum mass. Mixed germ cell tumor was initially diagnosed based on the pathologic findings of germinoma on thoracoscopic biopsy and clinical findings of elevated serum alpha-fetoprotein and beta-human chorionic gonadotropin. The patient received preoperative chemotherapy and subsequent complete resection of the residual tumor. Pathologic examination of the excised specimen showed predominantly malignant ganglioneuroma and small residual foci of teratoma. To our knowledge, this is the first reported case of a malignant ganglioneuroma arising from mediastinal mixed germ cell tumor.

Mediastinal germ cell tumors

Germ Cell Tumors (GCT) represent an important group of mediastinal tumors. Because of genetic characteristics and behavior have been divided in prepubertal and postpubertal tumors, and their origin remains controversial. The genetic changes are diverse, but the most frequent is i (12p), and can be associated to gonadal disgenesis. Histological classification is similiar to that of gonadal tumors and all histological types have been described in the mediastinum. Teratomas may undergo malignant transformation with the emergence of somatic tumors such as haematological malignancies, sarcomas, carcinomas and neurogenic tumors, and such transformation may occur in the primary site or in the metastases. Prognostic factors in mediastinal germ cell tumors include: age of the patient, histological type, distant metastases, stage, status of resection, level of serum tumor markers and proliferation markers. Immunohistochemistry is especially useful when the primary GCT is occult, to separate types of immature GCT, and to determine the lineage of malignant transformation which may be important to design treatment strategies.