Sinonasal teratocarcinosarcoma with yolk sac elements: a neoplasm of somatic or germ cell origin?

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Characterization of a Preclinical In Vitro Model Derived from a SMARCA4-Mutated Sinonasal Teratocarcinosarcoma

Sinonasal teratocarcinosarcoma (TCS) is a rare tumor that displays a variable histology with admixtures of epithelial, mesenchymal, neuroendocrine and germ cell elements. Facing a very poor prognosis, patients with TCS are in need of new options for treatment. Recently identified recurrent mutations in SMARCA4 may serve as target for modern therapies with EZH1/2 and CDK4/6 inhibitors. Here, we present the first in vitro cell line TCS627, established from a previously untreated primary TCS originating in the ethmoid sinus with invasion into the brain. The cultured cells expressed immunohistochemical markers, indicating differentiation of epithelial, neuroepithelial, sarcomatous and teratomatous components. Whole-exome sequencing revealed 99 somatic mutations including SMARCA4, ARID2, TET2, CDKN2A, WNT7A, NOTCH3 and STAG2, all present both in the primary tumor and in the cell line. Focusing on mutated SMARCA4 as the therapeutic target, growth inhibition assays showed a strong response to the CDK4/6 inhibitor palbociclib, but much less to the EZH1/2 inhibitor valemetostat. In conclusion, cell line TCS627 carries both histologic and genetic features characteristic of TCS and is a valuable model for both basic research and preclinical testing of new therapeutic options for treatment of TCS patients.

Teratocarcinosarcoma of the head and neck: Clinicopathologic review of a rare entity

Teratocarcinosarcoma is a rare, highly aggressive malignancy of the head and neck, characterized by multiphenotypic and triphasic growth of epithelial, mesenchymal, and primitive neuroepithelial elements. Owing to its rarity and morphological heterogeneity, as well as the lack of experience with this neoplasm, teratocarcinosarcoma is often misdiagnosed, particularly in small biopsy samples when only some of the elements are identified, thus leading to delayed management. Aggressive clinical behavior and poor survival outcomes, necessitate an accurate diagnosis and appropriate treatment. This review describes the main demographic and clinicopathological features of teratocarcinosarcoma, with an emphasis on the recent advances that have attempted to identify the molecular signature of this neoplasm.

Comprehensive Molecular Profiling of Sinonasal Teratocarcinosarcoma Highlights Recurrent SMARCA4 Inactivation and CTNNB1 Mutations

Sinonasal teratocarcinosarcoma (TCS) is a rare tumor defined by intermixed neuroepithelial, mesenchymal, and epithelial elements. While its etiology was historically ambiguous, we recently reported frequent SMARCA4 loss by immunohistochemistry, suggesting that TCS might be related to SMARCA4-deficient sinonasal carcinomas. However, other molecular alterations including CTNNB1 mutation have been reported in TCS, and its full genetic underpinnings are unclear. Here, we performed the first comprehensive molecular analysis of sinonasal TCS to better understand its pathogenesis and classification. We collected 30 TCS including 22 cases from our initial study. Immunohistochemical loss of SMARCA4 was seen in 22 cases (73%), with total loss in 18 cases (60%). β-catenin showed nuclear localization in 14 cases (64%) of the subset tested. We selected 17 TCS for next-generation sequencing with enrichment for partial or intact SMARCA4 immunoexpression. We identified inactivating SMARCA4 mutations in 11 cases (65%) and activating CTNNB1 mutations in 6 cases (35%), including 5 cases with both. Of 5 cases that lacked SMARCA4 or CTNNB1 mutation, 2 harbored other SWI/SNF complex and Wnt pathway alterations, including 1 with SMARCB1 inactivation and 1 with concomitant APC and ARID1A mutations, and 3 had other findings, including DICER1 hotspot mutation. These findings confirm that SMARCA4 inactivation is the dominant genetic event in sinonasal TCS with frequent simultaneous CTNNB1 mutations. They further underscore a possible relationship between TCS and sinonasal carcinomas with neuroendocrine/neuroectodermal differentiation. However, while SMARCA4 and β-catenin immunohistochemistry may help confirm a challenging diagnosis, TCS should not be regarded as a molecularly defined entity.

Congenital Teratocarcinosarcoma With CTNNB1 Gene Mutation Presenting as an Ocular Mass

Teratocarcinosarcoma is an extremely rare malignancy of the nasal cavity and paranasal sinuses. It exhibits both sarcomatous and carcinomatous components. Less than 100 cases are reported. It presents in adults with only two reported cases in infancy. Here we present a case of 3-week-old female with antenatally detected ocular mass. MRI revealed an exophytic right ocular mass (10 × 7.0 × 7.0 cm) with intracranial extension. The tumor consisted of malignant glands and mesenchymal elements of undifferentiated blastema-like cells and immature neuroepithelium. After an initial diagnosis and treatment for a Wilms tumor protocol, the mass showed no response. A second opinion rendered a diagnosis of sinonasal teratocarcinosarcoma. The patient underwent surgical resection and seven cycles of CNS ICE chemotherapy. A second debulking surgery revealed a very scant viable tumor with post-treatment changes. The patient is alive at 43 months on weekly vincristine maintenance. Molecular testing revealed a somatic CTNNB1 gene mutation. In conclusion, this is a rare and aggressive tumor which showed disease free survival beyond that reported in the literature with the appropriate use of multimodality therapy.

A sinonasal yolk sac tumor in an adult

Yolk sac tumors (YSTs), which are also called endodermal sinus tumors, are malignant tumors of germ cell origin. These tumors usually occur in the gonads, but 20% of cases have been reported at extragonadal sites. The head and neck is a rarely affected region that accounts for just 1% of all malignant tumors of germ cell origin. In addition, YSTs arise mostly in childhood. We present a rare pathologically pure case of primary adult YST in the sinonasal area. A 45-year-old male patient presented with a rapidly growing mass in the nasal cavity, which caused nasal obstruction and bloody post-nasal drip. The histopathologic features indicated pure YST, and immunohistochemical analysis revealed positive reactivity for Sal-like protein 4 and alpha-fetoprotein. Herein, we discuss the clinical, radiologic, and histologic features of this YST and review other cases of sinonasal YST in adults.

The first case report of primary thyroid teratocarcinosarcoma: An analog to sinonasal teratocarcinosarcoma

Teratocarcinosarcoma is a rare and aggressive tumor usually affecting the sinonasal tract. It arises primarily from the nasal cavity, paranasal sinuses with some reported cases arising from the nasopharynx and oral cavity and commonly referred to as Sinonasal Teratocarcinosarcoma (SNTC). We present the first case of teratocarcinosarcoma as a primary thyroid cancer in a 17-year-old male patient who presented with a rapidly growing anterior neck mass with no symptoms. Physical examination revealed circa 4 cm × 5 cm slightly right sided, non-tender, firm anterior neck swelling. A thyroid ultrasound revealed an enlarged thyroid gland with multiple thyroid nodes. Magnetic Resonance Imaging (MRI) of the head and neck showed no sinonasal tract tumor. Thyroidectomy and surgical resection of the tumor was performed. Histological examination revealed teratocarcinosarcoma of the thyroid gland, an analog to SNTC with no primary sinonasal tissue involvement. This implies that, teratocarcinosarcoma can occur in primary tissues other than sinonasal origin contrary to conventional knowledge.

Somatic-Type Yolk Sac Tumor Arising as a Predominant Component of Bladder Urothelial Carcinoma

Germ cell differentiation has been described in association with somatic tumors arising from several organ systems; rare cases arising from urothelium have been reported. Here we present a 62-year-old male with a remote history of lung cancer, a left adrenal gland mass, and a 5.6 cm left bladder wall mass; cystoscopy demonstrated a large papillary mass on the left anterior bladder wall. A transurethral resection specimen was sent for review in consultation and showed extensive papillary structures with thin fibrovascular cores lined by neoplastic cells with clear cytoplasm. These neoplastic cells were diffusely positive for pancytokeratin, CDX2 (caudal-type homebox 2), SALL4 (sal-like transcription factor 4), glypican-3, AFP (alpha-fetoprotein), while negative for PAX-8 (paired box gene 8), NKX3.1 (NK3 homeobox 1), PSA (prostate specific antigen), TTF-1 (thyroid transcription factor 1), Napsin A, inhibin, and OCT4 (octamer-binding transcription factor 4). Conventional urothelial conventional carcinoma and focal squamous differentiation were also identified as minor components. Urothelial carcinoma was focally positive for GATA3 (GATA-binding protein 3) and p63; SALL4 and glypican-3 were negative. Overall findings supported a yolk sac tumor with a smaller component of squamous cell carcinoma (<1%). Subsequent cystectomy showed similar morphologic features and immunoprofile in addition to foci of urothelial carcinoma and urothelial carcinoma in situ. No chromosome 12p abnormalities were identified by fluorescent in-situ hybridization study. A diagnosis of yolk sac tumor derived from urothelial carcinoma was made. Yolk sac tumor should be considered in the differential diagnosis of a high-grade urothelial carcinoma, particularly when glandular or other unusual architectural patterns are present. A somatic origin with underlying genomic instability similar to what has been described in the uterus and ovaries is suggested.

Case Report: SMARCB1 (INI-1)-Deficient Carcinoma of the Nasal Cavity with Pure Yolk Sac Tumor Differentiation and Elevated Serum AFP Levels

In adults, yolk sac tumors (YSTs) in the nasal cavity and paranasal sinuses are very rare. To date, only six cases have been reported in the English literature. YSTs in adults are often accompanied by cancer, teratocarcinosarcoma, and other malignant components. Here, we have reported a case of nasal tumor in a 55-year-old man with nasal obstruction and epistaxis. Morphologically, the tumor showed histological characteristics of pure YST. Immunohistochemical staining showed diffuse expression of SALL4, CDX2, and GPC-3 accompanied by sporadic expression of alpha-fetoprotein (AFP) and CD117. After 20 and 40 days of operation, the serum AFP level was 220.30 and 43.60 ng/mL (normal, <7 ng/mL), respectively, which supported the pathological diagnosis of YST. However, we further performed immunohistochemical staining and fluorescence in situ hybridization using an INI-1 probe to detect the status of INI-1 in tumor cells. The results revealed that INI-1 was absent in tumor cells. Hence, we corrected the diagnosis to SMARCB1 (INI-1)-deficient carcinoma of the nasal cavity with YST differentiation. The patient underwent surgery and adjuvant radiotherapy in our hospital without evidence of recurrence or metastasis at the 6-month follow-up. The serum AFP level had also normalized. In conclusion, our case demonstrates that INI-1-deficient carcinoma may exhibit, a pure YST differentiation and immunophenotype, and elevated serum AFP levels. In adults, YST in the nasal cavity may represent INI-1-deficient carcinoma, which may be a potential diagnostic pitfall.

In vitro Modeling of Embryonal Tumors

A subset of pediatric tumors affects very young children and are thought to arise during fetal life. A common theme is that these embryonal tumors hijack developmental programs, causing a block in differentiation and, as a consequence, unrestricted proliferation. Embryonal tumors, therefore typically maintain an embryonic gene signature not found in their differentiated progeny. Still, the processes underpinning malignant transformation remain largely unknown, which is hampering therapeutic innovation. To gain more insight into these processes, in vitro and in vivo research models are indispensable. However, embryonic development is an extremely dynamic process with continuously changing cellular identities, making it challenging to define cells-of-origin. This is crucial for the development of representative models, as targeting the wrong cell or targeting a cell within an incorrect developmental time window can result in completely different phenotypes. Recent innovations in in vitro cell models may provide more versatile platforms to study embryonal tumors in a scalable manner. In this review, we outline different in vitro models that can be explored to study embryonal tumorigenesis and for therapy development.

Recurrent Loss of SMARCA4 in Sinonasal Teratocarcinosarcoma

Molecular analysis has reshaped the landscape of high grade sinonasal tumors by defining novel entities and identifying recurrent mutations in established tumor types. However, sinonasal teratocarcinosarcoma (TCS), a rare and aggressive tumor with intermixed teratomatous, carcinomatous, and sarcomatous elements, remains poorly understood. The multiphenotypic differentiation of TCS has engendered persistent controversy about its histogenesis and leads to diagnostic overlap with several other malignancies. In this study, we evaluated the molecular underpinnings of TCS to clarify its pathogenesis and diagnosis. We performed SMARCA4 immunohistochemistry (IHC) on 22 TCS and 153 other sinonasal tumors. We identified loss of SMARCA4 expression in 18 TCS (82%), including 15 (68%) with complete loss and 3 (14%) with partial loss. Although we also identified partial SMARCA4 loss in 1 of 8 SMARCB1-deficient sinonasal carcinomas (13%), SMARCA4 was intact in all other sinonasal carcinomas and neuroendocrine tumors. We then selected 3 TCS with complete SMARCA4 loss by IHC for a targeted next-generation sequencing panel that included 1425 cancer-related genes. We confirmed biallelic somatic inactivation of SMARCA4 without other known oncogenic mutations in these 3 cases. Overall, these findings suggest that SMARCA4 inactivation may be the dominant genetic event in TCS, expanding understanding of this gene's role in sinonasal tumorigenesis. They also raise the possibility that TCS is on a diagnostic spectrum with the newly described SMARCA4-deficient sinonasal carcinoma, blurring the lines between established and emerging sinonasal entities. In addition, SMARCA4 IHC may provide a useful adjunct for confirming a diagnosis of TCS in limited material.

Treatment of Sinonasal Teratocarcinosarcoma: A Systematic Review and Survival Analysis

BACKGROUND

Sinonasal teratocarcinosarcoma (SNTCS) is a rare malignancy of the anterior skull base with only 127 cases described in the English literature. Given the rarity of this tumor, new cases and analysis of published reports may assist in future management of SNTCS.

OBJECTIVES

1) Describe findings from a systematic review of all available literature for malignant SNTCS including the clinical presentation, treatment modalities and outcomes. 2) Present two new cases of this rare anterior skull base tumor. 3) Compare treatment outcomes with respect to recurrence and mortality.

METHODS

A systematic review of all English literature available in 2 comprehensive databases was conducted by two independent reviewers using PRISMA guidelines. 85 publications were identified. Each case was reviewed for demographics, treatment and survival, and aggregate treatment outcomes were compared using Kaplan-Meier analysis.

RESULTS

A total of 64 articles meeting inclusion criteria were reported in the literature between 1977-2018. This represented a total of 127 patients, with a strong male predominance (83%) and mean age of 50 years (range 10-82). Mean follow-up was 21 months. Recurrence rate was 38%, with mean survival at 2 years of 55%. Almost all patients underwent surgery as a primary treatment modality (90%). The majority of cases were treated with multimodal therapy, with 55% receiving surgery and radiation and 20% receiving surgery with adjuvant chemoradiation. Kaplan-Meier analysis demonstrated a significant survival advantage for patients treated with combined therapy compared to surgery alone (p < 0.001) but did not show differences in recurrence (p = 0.085).

CONCLUSION

Two-year survival rates for SNTCS are 55%. Multimodality treatment outcomes appear to be superior to surgery alone based on the published data of this rare skull base tumor, although heterogeneity of treatment methods and reporting bias limits the generalizability of these findings.

Yolk sac tumor differentiation in urothelial carcinoma of the urinary bladder: a case report and differential diagnosis

Background

Yolk sac tumor (YST) is a germ cell neoplasm that arises predominantly in the gonads, but can also derive from somatic neoplasms in extragonadal locations. These latter cases have been documented in several organs, although reports from the urinary tract are limited. To our knowledge, this is the first report of a bladder urothelial carcinoma with a predominant component of YST differentiation.

Case presentation

We present a unique case of a 76-year-old man with a recurrent urinary bladder tumor, initially interpreted as a high grade urothelial carcinoma with glandular differentiation. In the recurrent tumor, diverse histological patterns were identified, including glandular, hepatoid and sarcomatoid. This tumor showed positivity for AFP, GLP3 and SALL4, and negativity for CK7 and EMA. Fluorescent in situ hybridization study showed a polysomic pattern of chromosome 12. All these findings led to the final diagnosis of a YST derived from urothelial carcinoma.

Conclusions

YST differentiation should be considered in the differential diagnosis of a high grade urothelial carcinoma, particularly when glandular and other unusual patterns are observed.

Translational genomics of sinonasal cancers

The sinonasal cavities harbor a wide variety of histologically distinct cancers, the majority very aggressive with 5-year survival rates between 30-60% and local recurrence as the main cause of death. This is a complex anatomic area, close to structures such the eyes and the brain, which is of special relevance for surgery and postoperative radiotherapy. The low incidence of these rare tumors hampers accumulation of experience with diagnosis and clinical managment as well as knowledge on recurrent genetic aberrations or testing of new treatment strategies. However, recent years have seen a growing number of publications on genetic aberrations providing data that can aid or fine-tune classification and provide molecular targets for treatment with specific inhibitors. In addition, new sinonasal cancer models are created that enable preclinical testing of candidate inhibitor drugs. With more and more novel targeted therapies being developed, options for personalized treatment of sinonasal cancer patients are now opening up.

Human germ cell tumours from a developmental perspective

Human germ cell tumours (GCTs) are derived from stem cells of the early embryo and the germ line. They occur in the gonads (ovaries and testes) and also in extragonadal sites, where migrating primordial germ cells are located during embryogenesis. This group of heterogeneous neoplasms is unique in that their developmental potential is in effect determined by the latent potency state of their cells of origin, which are reprogrammed to omnipotent, totipotent or pluripotent stem cells. Seven GCT types, defined according to their developmental potential, have been identified, each with distinct epidemiological and (epi)genomic features. Heritable predisposition factors affecting the cells of origin and their niches likely explain bilateral, multiple and familial occurrences of the different types of GCTs. Unlike most other tumour types, GCTs are rarely caused by somatic driver mutations, but arise through failure to control the latent developmental potential of their cells of origin, resulting in their reprogramming. Consistent with their non-mutational origin, even the malignant tumours of the group are characterized by wild-type TP53 and high sensitivity for DNA damage. However, tumour progression and the rare occurrence of treatment resistance are driven by embryonic epigenetic state, specific (sub)chromosomal imbalances and somatic mutations. Thus, recent progress in understanding GCT biology supports a comprehensive developmental pathogenetic model for the origin of all GCTs, and provides new biomarkers, as well as potential targets for treatment of resistant disease.

A rare case of intracranial teratocarcinosarcoma: Case report and review of literature

Background:

Teratocarcinosarcoma (TCS) is a rare malignant neoplasm with epithelial and mesenchymal components such as fibroblasts, cartilage, bone and smooth muscle. With less than 100 total reported cases, this malignant neoplasm is rarely encountered by neurosurgeons because it primarily involves the nasal cavity and paranasal sinuses.

Case Description:

A 55-year-old male with chronic frontal headaches was found to have a frontal mass with involvement of nasal sinus and right ethmoid sinus. The patient underwent preoperative embolization of tumor followed by bilateral frontal craniotomy for near total resection of the tumor. Patient did well postoperatively without new neurological deficits.

Conclusion:

Although cases with intracranial involvement are scarce, treatment with surgical resection with or without adjuvant treatments of chemotherapy and radiation therapy is the most widely accepted with goal for gross total resection. In our case, we achieved near total resection and the patient continues to do well without any gross neurological deficits.

Germ cell tumour growth patterns originating from clear cell carcinomas of the ovary and endometrium: a comparative immunohistochemical study favouring their origin from somatic stem cells

AIMS

To report a series of 11 ovarian and one endometrial neoplasm in elderly patients with mixed clear cell tumour and germ cell tumour (GCT) components, to compare their immunohistochemical profiles and demonstrate a putative stem cell population.

METHODS AND RESULTS

The clear cell tumours included 11 clear cell carcinomas (CCC) and one borderline clear cell tumour, while the GCT always included glandular yolk sac tumour (YST). In four cases, there were also foci of teratoma with immature neuroepithelial and endodermal tissues and undifferentiated areas showing true embryoids. To distinguish between the clear cell and YST components, the following antibodies were used: HNF1-β, napsin-A, cytokeratin 7 (CK7), PAX8, EMA, AFP, SALL4, villin, glypican-3 (GPC-3), GATA3, HepPar-1, OCT4, CDX2, CD30 and SOX2. HNF1-β, CK7, EMA and GPC-3 were often expressed in both components. Other markers had higher specificity for each cellular lineage; napsin-A and PAX8 were expressed only in CCC, while SALL4, villin, AFP and HepPar-1 were positive in the glandular YST component but negative in the clear cell component. OCT4 expression occurred in six of 10 cases and consistently in teratoma (four of four).

CONCLUSIONS

There is considerable immunophenotypical overlap between the two components in these mixed neoplasms, and a panel of markers should be used to facilitate the distinction. We propose that OCT4-expressing somatic cancer cells differentiate into GCT and represent spontaneously induced pluripotent stem cells, possibly conditioned by age-related epigenetic factors. These neoplasms have features of prepubertal type GCT showing lack of 12p gain, preponderance of YST and coexistence with immature neuroectoderm. However, there may also be undifferentiated stem cell areas with embryoid bodies, of the type seen in postpubertal testicular GCT, but lacking a complete embryonal carcinoma immunophenotype.

High-level expression of divergent endodermal lineage markers in gonadal and extra-gonadal yolk sac tumors

Yolk sac tumors occur at both gonadal and extra-gonadal sites. A recent case of ovarian endometrioid-pattern yolk sac tumor with strong diffuse expression of TTF-1 illustrated the potential for misdiagnosis due to divergent expression of endodermal lineage markers. The aim of this study was to investigate the expression of four divergent endodermal lineage markers, TTF-1, CDX2, Hep Par 1, and Napsin A, in gonadal and extra-gonadal yolk sac tumors of differing age, sex, and location (excluding foci of overt hepatoid differentiation). We identified 26 cases (5 ovarian, 15 testicular, and 6 extra-gonadal) containing yolk sac tumor as identified by typical histology and confirmed by positive immunohistochemical staining for alpha-fetoprotein and glypican-3. Mixed or ambiguous foci were confirmed by immunohistochemistry (SALL4 positive and Oct-4 negative). The relative proportion of three histologic patterns: reticular/cystic, solid/myxoid, and glandular was estimated. Percent positivity for the four divergent endodermal lineage markers was compared within yolk sac tumor areas according to site, age group, and histologic pattern. High-level (>25%) staining for one or more divergent endodermal lineage markers was seen in eleven cases: Hep Par 1 in seven cases, all post-pubertal, TTF-1 in four cases, two ovarian and two extra-gonadal, and CDX2 in three cases, with no age or site predilection. No case highly expressed all three divergent endodermal lineage markers, but four co-expressed high levels of two markers: two ovarian yolk sac tumors with TTF-1 and Hep Par 1, one testicular yolk sac tumor with CDX2 and Hep Par 1, and one extra-gonadal yolk sac tumors with TTF-1 and CDX2. While no absolute correlation of high-level divergent endodermal lineage marker expression with histologic subtype was observed, TTF-1 and CDX2 expression was predominantly seen in reticular/cystic and glandular areas while Hep Par 1 was most frequent in myxoid/solid and glandular areas.

Sinonasal yolk sac (Endodermal sinus) tumor in an adult female--A case report and review of the literature

Yolk sac tumor (YST), also known as endodermal sinus tumor, is a highly malignant germ cell tumor that is extremely rare in the sinonasal region, especially in adults. To the best of our knowledge, only five such cases have been reported till date (four men, one woman). We present a case of sinonasal YST admixed with transitional cell carcinoma in a 58-year-old female. Magnetic resonance imaging revealed a mass in the right ethmoid fissure infiltrating into the posterior and anterior ethmoid sinuses and nasopharynx. Positron emission tomography examination showed a maximum standardized uptake value of 6.8. Histological examination of the biopsy specimen revealed two distinct features, YST and transitional cell carcinoma, with evidence of mutual transition that indicated the composite nature of the tumor. Immunohistochemical analysis revealed positive immunoreactivity for Sal-like protein 4, α-fetoprotein and glypican3, and negative immunoreactivity for placental alkaline phosphatase, CD30 and CD117 in the YST component. P40 and P63 were detected only in transitional cell carcinoma component. The tumor was subsequently excised and four cycles of adjuvant chemotherapy at intervals of 3 weeks were administered. At 8 months after surgery, there was no evidence of tumor recurrence or metastasis. We have also presented a literature review on YST in sinusoids.

Sinonasal pure yolk sac tumor: a case report and literature review

Extragonadal pure yolk sac tumor of sinonasal origin is very rare. We report herein a case with sinonasal yolk sac tumor in a 1 year and 3 months old girl. The initial complaint was persistent nasal bleeding for about 2 months. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a lobulated soft tissue mass in paranasal sinus that extended to oral cavity, nasopharynx, and oropharynx. The histology showed typical features of yolk sac tumor and the positive immunohistochemical staining of SALL4 and α-fetoprotein. After tumor excision, adjuvant chemotherapy of JEB regimen was prescribed. After the follow-up for 13-months, α-fetoprotein was normal and neither tumor progression nor metastasis was found. We review the previous literature and discuss the etiology, histology, treatment, and the prognosis of the rare sinonasal yolk sac tumor.

Germ cell tumors of the ovary: an update

CONTEXT

The field of ovarian germ cell tumors (OGCTs) has remained relatively unchanged in the last 2 decades. However, the introduction of new stem cell pluripotency markers has provided a new understanding into the identification and taxonomy of OGCT types. New data have provided new insights into unusual teratoma-associated autoimmune disorders and the origin of gliomatosis peritonei.

OBJECTIVE

To review the impact of new pluripotency markers in the diagnosis of malignant OGCT (MOGCT) and analyze new nomenclature proposals and clinicopathologic entities.

DATA SOURCES

Ovarian germ cell tumors from routine material and expert consultation files at San Cecilio University Hospital, Granada, Spain, and the relevant literature were reviewed.

CONCLUSIONS

Although a correct diagnosis of MOGCT can often be made with histologic and classic immunohistochemical studies, the new immunohistochemical pluripotency markers give higher diagnostic accuracy. Germ cell tumors represent a caricature of the phases of normal embryonic differentiation from primordial germ and stem cells to extraembryonal and somatic tissue differentiation. Since every stage of differentiation and its related tumor type exhibit characteristic markers, the analysis of their expression facilitates tumor typing, thus complementing the use of classic antibodies. They also allow a more precise evaluation of the degree of immaturity in teratoma. The new term, primitive endodermal tumors, simplifies the understanding of the complex histology of the yolk sac tumor group, as this terminology encompasses its multiple endodermal differentiations. Recently described autoimmune encephalitis due to antibodies against the N-methyl-d-aspartate receptor has become the most frequent autoimmune disorder associated with ovarian teratoma.

Management of sinonasal teratocarcinosarcoma: a systematic review

PURPOSE

Sinonasal teratocarcinosarcoma (SNTCS) is a rare and highly malignant neoplasm that often involves the anterior skull base. This study reviews the published literature related to SNTCS. Clinical presentation, demographics, radiographic diagnosis, pathology, treatment, and management outcomes of this uncommon disease are reported.

METHODS

A systematic review in the published English literature was conducted. A MEDLINE/PubMed search and bibliographic examination of articles pertaining to SNTCS were performed. Each case was analyzed for patient demographics, clinical presentation, tumor location, diagnosis, treatment, and survival outcome.

RESULTS

A total of 49 journal articles were included. Individual patient data were reported in 86 cases. The average age of the patients was 54.5 years (range, 0.1 to 85 years), with a strong male predilection (7:1). Average follow-up was found to be 38.9 months (range, 2 to 372 months). The most common treatment method was surgery with radiation therapy, utilized in 59.3% of patients. Out of 71 cases with reported outcome and follow-up, there were 21 cases of recurrence, 8 cases with metastasis, and 6 cases reporting both recurrence and metastasis. Forty-two out of 71 (59.2%) patients survived at the time of follow-up.

CONCLUSIONS

This study describes the largest pool of SNTCS patients to date. SNTCS is a rare and aggressive malignant skull base tumor with a poor prognosis with frequent recurrence and metastasis. Although a variety of treatment paradigms have been reported in the literature, radical surgical resection followed by radiation therapy appears to be the most commonly used treatment option.

Sinonasal teratocarcinosarcoma with intracranial extension: case report and literature review

Sinonasal teratocarcinosarcoma (SNTCS) is an extremely rare malignancy of the paranasal sinuses that possesses the histopathologic features of both teratomas and carcinosarcomas. We report the case of a 58-year-old white man who presented with a 1-year history of a gradually enlarging left-sided nasal mass. The patient had previously undergone endoscopic sinus surgery at another facility, and the final pathologic specimen was reported as an SNTCS with positive margins. He was then referred to our institution, where he underwent a craniofacial resection combined with endoscopic intranasal resection. Postoperatively, he received combined chemotherapy and irradiation. At 48 months of follow-up, he was alive without evidence of disease.

The first reported generation of several induced pluripotent stem cell lines from homozygous and heterozygous Huntington's disease patients demonstrates mutation related enhanced lysosomal activity

Neuronal disorders, like Huntington's disease (HD), are difficult to study, due to limited cell accessibility, late onset manifestations, and low availability of material. The establishment of an in vitro model that recapitulates features of the disease may help understanding the cellular and molecular events that trigger disease manifestations. Here, we describe the generation and characterization of a series of induced pluripotent stem (iPS) cells derived from patients with HD, including two rare homozygous genotypes and one heterozygous genotype. We used lentiviral technology to transfer key genes for inducing reprogramming. To confirm pluripotency and differentiation of iPS cells, we used PCR amplification and immunocytochemistry to measure the expression of marker genes in embryoid bodies and neurons. We also analyzed teratomas that formed in iPS cell-injected mice. We found that the length of the pathological CAG repeat did not increase during reprogramming, after long term growth in vitro, and after differentiation into neurons. In addition, we observed no differences between normal and mutant genotypes in reprogramming, growth rate, caspase activation or neuronal differentiation. However, we observed a significant increase in lysosomal activity in HD-iPS cells compared to control iPS cells, both during self-renewal and in iPS-derived neurons. In conclusion, we have established stable HD-iPS cell lines that can be used for investigating disease mechanisms that underlie HD. The CAG stability and lysosomal activity represent novel observations in HD-iPS cells. In the future, these cells may provide the basis for a powerful platform for drug screening and target identification in HD.

Sinonasal teratocarcinosarcoma: a clinical and pathological analysis

The goal of this study was to assess the pathological and differential diagnoses of sinonasal teratocarcinosarcoma (SNTCS) in order to ultimately improve the diagnosis and treatment of this rare disease. Data from 2 cases of sinonasal teratocarcinosarcoma from the Wuxi People's Hospital (China) were analyzed. The clinical presentation for these patients consisted of nasal obstruction, epistaxis, and headache. On further physical examination, the presence of a polypoid mass was identified and, despite surgery and radiotherapy, both cases experienced recurrence. Histologically, the tumors showed a heterogeneous mixture of components from the 3 germ layers, primitive neuroepithelial elements, diagnostic immature squamous cell nests (clear cell nests), and various epithelial and mesenchymal components. Staining of the different germ layers corresponded with the appropriate immune markers. In case 1, the postradiotherapy resection specimen was completely dominated by a mature teratoma, with a complete absence of the corresponding adenocarcinoma and fibrosarcoma components. To date, this is the first study describing this composition within an SNTCS recurrent tumor. In summary, SNTCS is a rare tumor characterized by the presence of benign and malignant epithelial, mesenchymal, and dysembryomal components. Owing to its heterogeneous histologic appearance, adequate sampling and recognition of all SNTCS components are needed for future diagnosis. Currently, surgical removal, postoperative radiotherapy, and a histology-specific multidrug chemotherapy appear to be the best therapeutic approach. Future individualized therapy may also hold promise.