Sacrococcygeal teratomas: clinico-pathological characteristics and isochromosome 12p status

Extragonadal germ cell tumors: A clinicopathologic study with emphasis on molecular features, clinical outcomes and associated secondary malignancies

Extragonadal germ cell tumors (EGCTs) are rare, representing <5% of all germ cell tumors (GCTs). Whilst EGCTs share morphological and immunohistochemical features with their gonadal counterparts, they tend to be more aggressive and are frequently associated with secondary somatic malignancies. The aim of our study was to evaluate the clinical, morphological and immunohistochemical features, and to analyze tumors for chromosomal abnormalities of 12p, in addition to any novel genetic alterations, in a series of EGCTs. Seventy-seven EGCTs were included. Anterior mediastinum was the most common anatomic site, followed by central nervous system, retroperitoneum, sacroccygeal area, and neck. Whole genome SNP array identified isochromosome 12p in 26% of tumors. Additional cytogenetic abnormalities included the presence of gain of chr 21 in 37% of tumors. Somatic-type malignancies were identified in 8% of patients. Disease progression (metastasis and/or recurrence) was documented in 8 patients, most of whom died from their relapse. Three patients who died of disease had somatic-type malignancies. Mediastinal seminomas had a significantly better overall survival when compared to mediastinal non-seminomatous GCTs. Our study demonstrates that EGCTs share similar histologic features, but diverse clinical outcomes compared to their gonadal counterparts. Outcomes vary according to anatomic location and histologic subtypes. Our data corroborate that somatic-type malignancies are frequently encountered in mediastinal EGCTs and that their presence portends a poorer prognosis.

Case report: Mature extragonadal teratoma at the proximal part of the tail in a kitten

An 8-month-old, intact male, domestic shorthair cat was referred for a mass on the proximal ventral part of the tail which had been found since the animal was born, and due to the presence of a linear fissure with rows of ectopic teeth, the veterinarian suspected that the mass had recently ruptured. Tail amputation was elected and the entire mass was successfully surgically excised. From the gross examination, this mass had an open cyst-like structure with a prominent area composed of hair, teeth, and bone. Histopathology revealed two components of germinal layers including hair follicles, adnexal tissue, neural tissue, teeth, muscle, fat, bone, and lymphatic vessels. The histopathological diagnosis was consistent to mature teratoma. Although, complete excision could not be definitively confirmed histologically, this kitten is currently well and has not developed any recurrent mass at the surgical site after 2 years of post-operation.

Primary mediastinal germ cell tumours: an immunohistochemical and molecular diagnostic approach

AIMS

Primary mediastinal germ cell tumours (PMGCTs) are rare mediastinal neoplasms and their diagnosis can be challenging due to small biopsy samples. The aim of this study was to elaborate a diagnostic algorithm using immunohistochemical stainings with focus on novel markers and molecular analysis of isochromosome 12p [i(12p)].

METHODS AND RESULTS

Paraffin-embedded tissues of 32 mediastinal tumours were analysed using immunohistochemical stainings for SALL4, LIN28, OCT3/4, D2-40, CD117, SOX17, SOX2, CD30, ß-hCG, GATA3, FOXA2, GPC3, AFP, TdT, NUT and pan-cytokeratin. Quantitative real-time polymerase chain reaction (qPCR) was performed to investigate i(12p) status. Fifteen seminomas, seven teratomas, one yolk sac tumour, one choriocarcinoma and seven mixed PMGCT were diagnosed. Each entity had different immunohistochemical staining patterns which helped to distinguish them: seminoma (OCT3/4, D2-40, CD117, TdT), embryonal carcinoma (OCT3/4, SOX2), yolk sac tumour (FOXA2, GPC3, AFP) and choriocarcinoma (ß-hCG, GATA3). Mature teratomas stained positive for pan-cytokeratin in epithelial components and focally for SALL4, SOX2, GATA3, D2-40 and FOXA2. Furthermore, a NUT carcinoma mimicking a PMGCT was diagnosed showing a strong nuclear SOX2 and speckled nuclear NUT staining. i(12p) was detected in 24 out of 27 PMGCTs [89%].

CONCLUSION

A diagnostic algorithm is of great importance for a reliable diagnosis of PMGCTs in the usually small tissue biopsy samples. Therefore, a combination of three to four antibodies to identify the correct histological subtype is usually necessary in addition to morphological features. The i(12p) status serves as an additional option to underline germ cell origin in selected cases.

Lack of genetic homozygosity in prepubertal teratomas: divergent pathogenesis distinct from that of teratomas in adolescents

In adults, both immature and mature ovarian teratomas show frequent genetic homozygosity consistent with tumorigenesis involving germ cells after meiosis I. Investigation into genetic zygosity of various teratomas in children has been limited. Thirteen sacrococcygeal, 12 ovarian, and 3 testicular teratomas in children 18 years or younger were retrieved from our departmental archives and histologically reviewed. Tumor and paired normal tissues were microdissected and subjected to short tandem repeat (STR) genotyping. DNA genotyping was informative in 12 sacrococcygeal teratomas, 8 ovarian teratomas, and 3 testicular teratomas. Sacrococcygeal teratomas included seven mature teratomas, four immature teratomas, and one mixed germ cell tumor with patient age ranging from 0 days to 3 years. All but two patients were female. Ovarian teratomas included five mature and three immature teratomas with patient age ranging from 2 to 18 years. Testicular teratomas included two mature teratomas and one immature teratoma with patient age ranging from 3 months to 3 years. All sacrococcygeal, testicular, and ovarian teratomas in patients younger than 4 years showed no evidence of genetic homozygosity by STR genotyping. In contrast, all four ovarian teratomas in patients older than 9 years showed either partial or complete homozygosity. In conclusion, unlike adolescent and adult ovarian teratomas, prepubertal sacrococcygeal and gonadal teratomas lack genetic homozygosity, supporting the hypothesis that teratomas before puberty develop at an early stage of germ cell development different from that of teratomas in adolescents and adults.

Meningioma in mature cystic teratoma of the ovary: clinical and computed tomography findings

Background

Mature cystic teratoma (MCT) with meningioma of the ovary is a very rare benign tumor. There is only 3 reports of this disease until June 2019. The aim of the present study was to describe a ovarian mature cystic teratoma containing meningioma and nests of neuroblasts in a 15-year-old girl.

Methods

The method used in the present study consists of description of the clinical history, image lab features, and pathological result.

Results

The patient complained of a 2-month history of irregular vaginal bleeding. Abdominal computed tomography (CT) showed a large oval cystic-solid mass with septations and fat density shadow, in abdomen pelvic cavity. The cystic part was the main component in the mass. The tumoral solid parts and its internal division could be seen intensified from slight to moderate on contrast-enhanced CT images compared with those on precontrast images, and the solid parts showed heterogeneous enhancement. Neighbouring intestinal tract and the uterus displaced by compression. The pathological examination confirmed the diagnosis.

Conclusions

The clinical feature of ovarian mature cystic teratoma with meningioma includes a lack of specificity. Only meticulous recording of the gross features, histopathological examination including immunohistochemistry and supportive clinical and radiological findings to arrive at a correct diagnosis in case of unconventional tumours. If necessary, preoperative puncture can be performed.

Extragonadal germ cell tumors: Not just a matter of location. A review about clinical, molecular and pathological features

Extragonadal germ cell tumors (EGGCTs) are uncommon neoplasms, which arise in anatomical locations other than gonads. The pathogenesis of these neoplasms is still poorly understood and it is a matter of debate if they really represent extragondal primary neoplasms or rather extragondal metastasis from occult gonadal neoplasms. The actual observations suggest that EGGCTs represent a unique entity, so their biology and behavior are substantially different from gonadal counterparts. The diagnosis of EGGCTs is often challenging, and differential diagnosis is particularly wide. Nevertheless, a correct diagnosis is essential for the correct management of the patient. We summarize the state of art about EGGCTs, with particular emphasis on diagnosis and prognosis.

Pathogenesis of Testicular Germ Cell Neoplasia: A Conceptual Approach

Testicular germ cell tumors are a diverse group of neoplasms, consisting of the prepubertal type 1 tumors, pure teratoma, and pure yolk sac tumor, the type 2 tumors, which are biologically malignant, preceded by germ cell neoplasia in situ, and harbor chromosome 12p abnormalities, and the type 3 tumor, spermatocytic tumor, which features chromosome 9p amplification. These arise in distinct clinical settings, and harbor distinct genetic abnormalities, immunohistochemical properties, and morphologic features. Here we have attempted to unify embryology, morphology, immunohistochemistry, and genetics in order to distill this fascinating group of neoplasms into what we hope is a useful framework for understanding their classification.

Clinicopathologic Features and Chromosome 12p Status of Pediatric Sacrococcygeal Teratomas: A Multi-institutional Analysis

Chromosome 12p gains are typically present in postpubertal male patients with testicular malignant germ cell tumors, including most teratomas, and absent in pure ovarian teratomas, both mature and immature. We sought to evaluate the clinicopathologic features and chromosome 12p status of pediatric patients with sacrococcygeal teratomas (SCTs) using the institutional databases of 2 tertiary medical centers. Seven mature teratomas (3 pure, 2 with yolk sac tumor, 1 with medulloepithelioma, and 1 with ependymoma) and 3 immature teratomas (2 pure: grade 2 and grade 3 and 1 mixed: grade 3 with yolk sac tumor) were identified. All patients underwent surgery and 2 received adjuvant chemotherapy. Fluorescence in situ hybridization analysis was performed to elucidate chromosome 12p gains, including isochromosome 12p. All 10 tumors analyzed lacked 12p gains regardless of the components. No patient had evidence of disease at their most recent interval follow-up (mean: 30, range: 7-91 months), irrespective of margin status or of receiving chemotherapy. Overall, our study suggests an absence of chromosome 12p abnormalities in clinically nonaggressive SCTs. Additional data are required to confirm these findings before definitive patient care recommendations can be made.

Adrenal Teratoma: a Case Series and Review of the Literature

Adrenal teratomas are rare neoplasms and there is limited data on their surgical outcomes and long-term prognosis. We aimed to review our institutional experience and compare this to the existing literature on adrenal teratomas in adults and children. An institutional pathology database was searched for cases of adrenal teratoma (June 1956-July 2016). Clinical and imaging data were abstracted from the medical records and pathology slides were obtained for review. In addition, a PubMed search for "adrenal teratoma" from June 1952 to July 2016 was performed to identify reports of primary adrenal teratoma in patients of all ages. Of 7706 patients who underwent adrenalectomy during the study period at our institution, three patients were identified with adrenal teratoma. Patients were 24, 26, and 29 years of age, respectively. Two patients presented with abdominal pain and two of the three underwent a laparoscopic adrenalectomy. A pathologic examination revealed mature cystic teratomas that frequently displayed well-differentiated respiratory, digestive, and squamous epithelia. Eighteen case reports in the literature were identified in patients 17-61 years of age. Patients presented most frequently with abdominal or flank pain (63.6%). Median tumor diameter was 9.0 cm and tumors were frequently left-sided (81.8%), cystic (63.6%), and calcified (72.7%) on either radiologic or pathologic examination. Primary adrenal teratomas are rare neoplasms that typically present as large, left-sided nodules with cystic and calcified components seen radiographically. Although the data are limited, they are generally amenable to laparoscopic resection and have a very favorable prognosis.

The Case of an Elderly Male Patient with Unknown Primary Mucinous Adenocarcinoma within Presacral Teratoma (Teratoma with Malignant Transformation)

Teratomas are rarely seen in adults, and presacral region is an area where they rarely settle in. Similarly, only about 1% of teratomas show malignant transformation. Malignant transformation is often associated with the area where teratoma settles in. Malignant transformation of mediastinal teratomas is more frequent than the ones located in retroperitoneal area and gonad. They most commonly show rhabdomyosarcoma, primitive neuroectodermal tumor, enteric adenocarcinoma, and leukemia transformation. In teratomas showing malignant transformation, the clinical course is aggressive; and survival of patients with metastatic disease is very low. The primary treatment of teratomas with malignant transformations is surgical. Effect of radiotherapy and chemotherapy is not clear in patients, to whom surgical operation cannot be applied, or those who are with residual tumor, even if surgical operation can be applied to them, or those who are at metastatic stage. In this paper, we presented a 76-year-old male patient due to the histologic diagnosis of mucinous adenocarcinoma within teratoma, in whom approximately 7 cm presacral mass was found during the radiographic examination made by the reason of low back pain and pelvic pain.