Sacrococcygeal Meningocele Antenatally Misdiagnosed as Teratoma: A Case Report

Sacrococcygeal masses encompass a diverse range of pathologies. Prenatal ultrasound facilitates early detection of congenital sacrococcygeal masses. We present the case of a newborn of a 22-year-old woman who was identified to have a sacrococcygeal mass by prenatal ultrasound that was initially diagnosed as sacrococcygeal teratoma. On examination after delivery, a large midline mass in the sacrococcygeal region was observed, which was globular in shape and had smooth, thin skin with bluish discoloration. Magnetic resonance imaging revealed a cystic lesion that protruded through a caudal sacral defect, consistent with a sacrococcygeal meningocele. The patient underwent surgical repair of the meningocele without any intraoperative complications and had preserved motor function in the lower extremities after the procedure. This case underscores the challenge of distinguishing sacrococcygeal teratoma from meningocele based on clinical presentation and prenatal ultrasound findings. An accurate preoperative diagnosis is essential for effective surgical planning.

Computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography findings for the diagnosis of malignant struma ovarii: A case report

Malignant struma ovarii (MSO) is an extremely rare disease arising from struma ovarii. Preoperative diagnosis is still challenging due to the lack of criteria for imaging findings. Herein, we report a case of MSO with suggestive imaging findings for a 50-year-old woman who presented with a pelvic tumor. The tumor did not typically show characteristic imaging findings of struma ovarii; however, the findings implied colloids of thyroid tissue within solid components on the magnetic resonance imaging (MRI) and computed tomography. Additionally, the solid components showed hyperintensity on diffusion-weighted image and hypointensity on apparent diffusion coefficient maps. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were performed. Histopathological examination revealed MSO of the right ovary, pT1aNXM0. The distribution of papillary thyroid carcinoma tissue corresponded to restricted diffusion area on MRI. In conclusion, the coexistence of imaging findings suggesting thyroid tissue and restricted diffusion in the solid component on MRI could indicate MSO.

Linking human Dead end 1 (DND1) variants to male infertility employing zebrafish embryos

STUDY QUESTION

Is the vertebrate protein Dead end (DND1) a causative factor for human infertility and can novel in vivo assays in zebrafish help in evaluating this?

SUMMARY ANSWER

Combining patient genetic data with functional in vivo assays in zebrafish reveals a possible role for DND1 in human male fertility.

WHAT IS KNOWN ALREADY

About 7% of the male population is affected by infertility but linking specific gene variants to the disease is challenging. The function of the DND1 protein was shown to be critical for germ cell development in several model organisms but a reliable and cost-effective method for evaluating the activity of the protein in the context of human male infertility is still missing.

STUDY DESIGN, SIZE, DURATION

Exome data from 1305 men included in the Male Reproductive Genomics cohort were examined in this study. A total of 1114 of the patients showed severely impaired spermatogenesis but were otherwise healthy. Eighty-five men with intact spermatogenesis were included in the study as controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We screened the human exome data for rare, stop-gain, frameshift, splice site, as well as missense variants in DND1. The results were validated by Sanger sequencing. Immunohistochemical techniques and, when possible, segregation analyses were performed for patients with identified DND1 variants. The amino acid exchange in the human variant was mimicked at the corresponding site of the zebrafish protein. Using different aspects of germline development in live zebrafish embryos as biological assays, we examined the activity level of these DND1 protein variants.

MAIN RESULTS AND THE ROLE OF CHANCE

In human exome sequencing data, we identified four heterozygous variants in DND1 (three missense and one frameshift variant) in five unrelated patients. The function of all of the variants was examined in the zebrafish and one of those was studied in more depth in this model. We demonstrate the use of zebrafish assays as a rapid and effective biological readout for evaluating the possible impact of multiple gene variants on male fertility. This in vivo approach allowed us to assess the direct impact of the variants on germ cell function in the context of the native germline. Focusing on the DND1 gene, we find that zebrafish germ cells, expressing orthologs of DND1 variants identified in infertile men, failed to arrive correctly at the position where the gonad develops and exhibited defects in cell fate maintenance. Importantly, our analysis facilitated the evaluation of single nucleotide variants, whose impact on protein function is difficult to predict, and allowed us to distinguish variants that do not affect the protein's activity from those that strongly reduce it and could thus potentially be the primary cause for the pathological condition. These aberrations in germline development resemble the testicular phenotype of azoospermic patients.

LIMITATIONS, REASONS FOR CAUTION

The pipeline we present requires access to zebrafish embryos and to basic imaging equipment. The notion that the activity of the protein in the zebrafish-based assays is relevant for the human homolog is well supported by previous knowledge. Nevertheless, the human protein may differ in some respects from its homologue in zebrafish. Thus, the assay should be considered only one of the parameters used in defining DND1 variants as causative or non-causative for infertility.

WIDER IMPLICATIONS OF THE FINDINGS

Using DND1 as an example, we have shown that the approach described in this study, relying on bridging between clinical findings and fundamental cell biology, can help to establish links between novel human disease candidate genes and fertility. In particular, the power of the approach we developed is manifested by the fact that it allows the identification of DND1 variants that arose de novo. The strategy presented here can be applied to different genes in other disease contexts.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the German Research Foundation, Clinical Research Unit, CRU326 'Male Germ Cells'. There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Differentially expressed messenger RNA/proteins can distinguish teratoma from necrosis in postchemotherapy retroperitoneal lymph node dissection tissue

BACKGROUND

Before postchemotherapy retroperitoneal lymph node dissection (pcRPLND), in patients with metastasized germ cell tumors (GCTs), those harboring necrosis (NEC) cannot be distinguished from those who have teratoma (TER), resulting in relevant overtreatment, whereas microRNA-371a-3p may be predictive for viable GCT. The purpose of this study was to explore messenger RNA (mRNA) and proteins to distinguish TER from NEC in pcRPLND tissue.

METHODS

The discovery cohort consisted in total of 48 patients, including 16 each with TER, viable GCT, and NEC. Representative areas were microdissected. A NanoString panel and proteomics were used to analyze 770 genes and >5000 proteins. The most significantly and differentially expressed combination of both parameters, mRNA and its associated protein, between TER and NEC was validated using immunohistochemistry (IHC) in an independent validation cohort comprising 66 patients who were not part of the discovery cohort.

RESULTS

The authors observed that anterior gradient protein 2 homolog (AGR2) and keratin, type I cytoskeletal 19 (KRT19) were significantly differentially expressed in TER versus NEC in mRNA and protein analyses (proteomics). The technical validation using IHC was successful in the same patients. These proteins were further validated by IHC in the independent patient cohort and exhibited significantly higher levels in TER versus NEC (p < .0001; area under the curve, 1.0; sensitivity and specificity, 100% each).

CONCLUSIONS

The current study demonstrated that KRT19 and AGR2 mRNA and protein are overexpressed in TER versus NEC in pcRPLND tissue and might serve as a future diagnostic target to detect TER, for instance, by functional imaging, to avoid overtreatment.

PLAIN LANGUAGE SUMMARY

The proteins and the corresponding genes called AGR2 and KRT19 can differentiate between teratoma and necrosis in remaining tumor masses after chemotherapy in patients who have metastasized testicular cancer. This may be a way to improve presurgical diagnostics and to reduce the current overtreatment of patients with necrosis only, who could be treated sufficiently by surveillance.

Hyperechoic mass of the right ventricle in adults: A rare presentation of an intracardiac teratoma

Cardiac teratomas are very rare primary tumors; most are intrapericardial, while a few are intracardiac. Furthermore, most reported intracardiac teratomas are in the pediatric population, with few cases of secondary metastases from testicular teratomas reportedly manifesting in adults. Here, we report a rare case of a mature cystic teratoma in the right ventricle complicated by a bicuspid aortic valve (BAV) in an adult. Echocardiography and enhanced computed tomography (CT) were performed, and the mass was surgically excised. A pathological examination confirmed the diagnosis of a mature cystic teratoma. Meanwhile, mechanical valve replacement of the aortic valve was performed. No tumor recurrence or symptoms occurred in the 2-year follow-up. This is the first report of an adult primary intracardiac teratoma with solid hyperechoic findings on echocardiography and a BAV.

A patient with advanced breast cancer and hyperthyroidism associated with struma ovarii

Not required for Clical Vignettes.

A giant teratoma in the anterior mediastinum found prenatally: A case report

Prenatal anterior mediastinal teratomas are rare. Anterior mediastinal teratomas can cause edema during the perinatal period. Color Doppler ultrasonography and chest computed tomography (CT) are of great value in diagnosing neonatal anterior mediastinal teratomas. Here, we report a case of prenatally diagnosed neonatal anterior mediastinal teratoma. After birth, transthoracic echocardiography and chest enhanced CT showed a large solid mass in the pericardial cavity. Owing to compression of the heart, the tumor was completely removed 1 day after birth, and cardiopulmonary bypass was performed. Pathology results indicated an immature teratoma (Grade I). At 9-month follow-up, the patient remained in good overall condition without observed recurrences.

18F-Flurodeoxyglucose Positron Emission Tomography/Computed Tomography Findings in a Rare Case of Trichoptysis

Trichoptysis or coughing of hairs is a rare symptom, but is pathognomonic for a teratoma with tracheobronchial communication. We present such a rare case with 18F-flurodeoxyglucose positron emission tomography/computed tomography (PET-CT) imaging findings in a 20-year-old female. The diagnosis was made with PET-CT and she underwent curative surgical resection after that.

Teratoma of the Tongue in a Fetus: A Case Report and Review of the Literature

Teratomas are tumors composed of multiple embryonic germ layers of tissue, and those occurring in the tongue of the fetus are extremely rare. This paper reports the case of a 20-week-old fetus diagnosed with oral masses combined with a cleft lip and palate using prenatal ultrasonography. The patient decided to terminate the pregnancy due to economic factors after prenatal genetic consultation. The mother underwent induction termination and delivered a stillborn male fetus. The mass originated from the tongue and was pathologically confirmed as a mature teratoma by histology. Teratoma of the tongue is a rare congenital tumor that is usually benign. Its etiology is multifactorial, and prenatal karyotyping is necessary. Ultrasound is the main method of prenatal diagnosis, and magnetic resonance imaging is an effective complement to ultrasonography. Tumors can cause other malformations and abnormalities, and their location and size have an essential impact on prognosis. The imaging approach should focus on the associated abnormalities in order to assess the impact of the mass on the fetal airway and swallowing. Appropriate follow-up imaging can be helpful in the dynamic assessment of management.

Unresectable Metastatic Testicular Germ Cell Tumor With Low-grade Neuroglial Neoplasm, Stable After Radiation and Chemotherapy

We present an 18-year-old male patient who presented with a 16 cm testicular tumor alongside multiple lesions in the lungs, right pelvis with involvement of the ischio/pubic bone, and enlarged pelvic lymph nodes on imaging, suspicious for metastatic disease. Histologic and immunohistochemical examinations revealed an embryonic type neuroectodermal tumor (somatic-type malignancy, 10%) arising in a malignant mixed germ cell tumor composed of teratoma (50%), embryonal carcinoma (10%) and yolk sac tumor (30%). After treatment with chemotherapy and radiation, repeat imaging demonstrated a right pelvic sidewall mass that decreased in size from 40 mm at 11 months after the initial diagnosis to 18 mm at 22 months after the initial diagnosis. A right pelvis medial thigh wall mass that had a lytic bone component showed a slight increase in size from 151 mm at 11 months after the initial diagnosis to 154 mm at 22 months after the diagnosis. On biopsies performed at 3, 10, and 26 months after the initial diagnosis, this lytic lesion consistently demonstrated a neoplasm composed of low-grade neuroglial differentiation. This is the first case in the medical literature where a residual malignant germ cell tumor consisting of low-grade neuroglial neoplasm is in a site that is not amenable to resection without significant morbidity. The tumor initially regressed with the traditional first-line chemo-radiotherapy regimen but regrew and stabilized with a second regimen of chemotherapy. The clinical course of this case invites consideration for an active surveillance approach in cases with similar characteristics.

An operation on placental support in a fetus with a nasopharyngeal teratoma

Airway obstruction diagnosed antenatally in the fetus due to congenital high airway obstruction syndrome or nasopharyngeal masses are the primary indications for performing an operation on placental support. Prenatally diagnosed nasopharyngeal masses pose the risk of total airway obstruction upon delivery. Placental support utilises uteroplacental blood flow to facilitate an airway intervention on the fetus while maintaining oxygenation. These interventions must be completed in under 20 min due to amniotic fluid loss and uterine contractions. This case report describes the anaesthetic management of a fetus with a nasal teratoma. In this report, we discuss the clinical indications and anaesthetic considerations of the operation on placental support procedure for nasopharyngeal masses.

A 6-month-old girl with mesenteric teratoma: A Case report and literature review

An otherwise healthy 4-month-old girl presented to the community health service center because her abdomen was distended. Over the next 2 months, the girl's abdomen gradually became more distended. Her examination was notable for abdominal distention with a large, mobile, non-tender abdominal mass. Abdominal ultrasound images and subsequently obtained CT images showed a large, circumscribed cystic and solid mass. This led to the presumptive diagnosis of teratoma of the mesentery. The mass was completely resected during a laparotomy. The pathology, along with the surgical findings and imaging, led to the final diagnosis.

Fetus-in-Fetu: A Differential Diagnosis of Neonatal Fetiform Encysted Abdominal Mass

Fetus-in-fetu (FIF) is a rare embryological anomaly in which an encysted fetiform mass develops within the infant or adult host body. It mainly occurs intraabdominal. There are embryo-pathogenetic debates over whether it belongs to the spectrum of highly differentiated teratomas or is a parasitic twinning from a monozygotic monochorionic diamniotic pregnancy. The presence of vertebral segments and an encapsulating cyst can reliably distinguish FIF from teratoma. The diagnosis may be initially made by imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), and a confirmatory diagnosis made by histopathology of the excised mass. Our center experienced a case of a male neonate presented after emergency cesarean delivery at 40-week gestation with the suspicion of an intraabdominal mass identified antenatally. Antenatal ultrasonography at 34 weeks gestation suggested the presence of an intraabdominal cystic mass measuring 6.5 cm with a hyperechoic focus. A follow-up MRI performed after the delivery showed a well-defined mass with the cystic formation in the left abdominal region with a centrally located fetiform structure. Vertebral bodies and long limb bones were visualized. The diagnosis of FIF was initially made preoperatively by the characteristic findings of imaging studies. Laparotomy was scheduled on day 6, revealing a large encysted mass with fetiform content. FIF should be considered a possible differential diagnosis of neonatal encysted fetiform mass. Routine antenatal imaging permits more frequent antenatal detection with earlier workup and management.

Adult sacrococcygeal teratoma: A review

Sacrococcygeal teratomas (SCT) in adults are extremely rare, and most SCTs are located either mainly outside the pelvis, with a small number of intrapelvic components, or mostly in the pelvis (types III and IV). The etiology of teratomas remains unknown. Most teratomas are benign, and approximately 1 to 2% of teratomas undergo malignant transformation, including squamous cell carcinoma, adenocarcinoma, sarcoma, and other malignancies. Most SCTs grow insidiously, and their symptoms are not easily detected in the early stages. Some cases may only be discovered through physical examination or compression symptoms when the tumor reaches a detectable size. Computed tomography and magnetic resonance imaging have high detection rates for presacral space-occupying lesions and can provide imaging details with guiding significance for the selection of surgical methods. Surgical resection is the preferred treatment option for SCT and can determine the pathological type. Common sacrococcygeal malignancies are mainly immature teratomas and mature teratomas. When the presence of malignant components is confirmed, the treatment model should be adjusted according to pathological type.

Fetal Brain Tumors, a Challenge in Prenatal Diagnosis, Counselling, and Therapy

Fetal brain tumors are a rare entity with an overall guarded prognosis. About 10% of congenital brain tumors are diagnosed during fetal life. They differ from the postnatally encountered pediatric brain tumors with respect to location and tumor type. Fetal brain tumors can be benign or malignant and infiltrate or displace adjacent brain structures. Due to their high mitotic rate, they can show rapid growth. Outcome depends on age of diagnosis, size, and histological tumor type. Findings like polyhydramnios and macrocephaly encountered on routine ultrasound are frequently associated. Detailed prenatal anomaly scan and subsequent fetal magnetic resonance imaging (MRI) may identify the brain tumor and its severity. Both maternal and fetal prognosis should be included in prenatal counselling and decision making.

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.

Twin Fetus-in-Fetu: The Story of an Encaged Twin

Background: Fetus-in-fetu (FIF) features a monozygotic, diamniotic, parasitic twin enclosed within its host twin. Case report: An 11-month baby girl presented with an antenatal diagnosis of a retroperitoneal mass. Radiological findings suggested it to be a teratoma. The mass was excised in-toto, histological findings were consistent with fetus-in-fetu. Conclusions: FIF may not have identifiable vertebral bodies and limbs upon imaging. Organized organ systems help differentiate this from a teratoma.

Intraosseous Epidermoid Cyst: a Case Report

BACKGROUND

Epidermoid cysts are benign lesions that occur throughout the body. Their development in the oral cavity is extremely rare. Intraosseous epidermoid cysts of the jaw are even rarer and difficult to distinguish from other lesions. For this reason, we would like to draw the attention of practitioners to this pathology as a differential diagnosis through the presented clinical case.

METHODS

This study presents an unusual case of a type of epidermoid cyst in an edentulous maxilla. A 70-year-old man was referred to the Maxillofacial Surgery Division at the University Multiprofile Hospital for Active Treatment and Emergency Medicine "N. I. Pirogov", Sofia, Bulgaria, for a single radiolucent area in his anterior maxilla. The patient underwent surgery to extract the cyst.

RESULTS

Based on the clinical and radiographic evaluation, a preliminary diagnosis of dentigerous residual cyst was made. The histopathological examination of the hematoxylin and eosin stained sections revealed an epidermoid cyst based on the observed thick keratin layer resembling epidermis together with the stratified squamous epithelium lining with many layers of sheaves of orthokeratin.

CONCLUSIONS

This report presents an uncommon case of an intraosseous epidermoid cyst occurring without a history of maxillary trauma. Although intraosseous epidermoid cysts are extremely rare in jaws, they should be considered in the differential diagnosis of radiolucent lesions.

An introduction to the WHO 5th edition 2022 classification of testicular tumours

The 5th edition of the World Health Organisation Blue Book was published recently and includes a comprehensive update on testicular tumours. This builds upon the work of the 4th edition, retaining its structure and main nomenclature, including the use of the term 'germ cell neoplasia in situ' (GCNIS) for the pre-invasive lesion of most germ cell tumours and division from those not derived from GCNIS. While there have been important developments in understanding the molecular underpinnings of testicular cancer, this updated classification paradigm and approach remains rooted in morphology. Nomenclature changes include replacement of the term 'primitive neuroectodermal tumour' by 'embryonic neuroectodermal tumour' based on the non-specificity of the former term and to separate these tumours clearly from Ewing sarcoma. Seminoma is placed in a germinoma family of tumours emphasising relation to those tumours at other sites. Criteria for the diagnosis of 'teratoma with somatic transformation' have been modified to not include variable field size assessments. The word 'carcinoid' has been changed to 'neuroendocrine tumour', with most examples in the testis now classified as 'prepubertal type testicular neuroendocrine tumour'. For sex cord-stromal tumours, the use of mitotic counts per high-power field has been changed to per mm2 for malignancy assessments, and the new entities, 'signet ring stromal tumour' and 'myoid gonadal stromal tumour', are defined. Well-differentiated papillary mesothelial tumour has now been defined as tumour type with a favourable prognosis. Sertoliform cystadenoma has been removed as an entity from testicular adnexal tumours and placed with Sertoli cell tumours.

Establishment of the removal method of undifferentiated induced pluripotent stem cells coexisting with chondrocytes using R-17F antibody

Aim: Tumorigenicity of residual undifferentiated induced pluripotent stem cells (iPSCs) is a major concern. The purpose of this study was to investigate the optimal conditions for removal of iPSCs using R-17F antibody, which recognizes specific glycosphingolipids glycans on undifferentiated iPSCs and exhibits selective cytotoxicity to iPSCs. Materials & methods: After adding of R-17F and secondary antibody to co-cultured iPSCs and chondrocytes, residual iPSCs were quantitatively evaluated by iPS specific glycome analysis. Results: Undifferentiated iPSCs were sufficiently removed using R-17F in combination with an equal amount of a secondary antibody. Furthermore, teratomas were not observed upon transplantation of co-cultured cells pretreated under the same conditions into testes of immunodeficient mice. Conclusion: This removal method incorporating R-17F may be useful for regenerative medicine using iPSCs.

Sacrococcygeal teratoma: evaluation of its approach, treatment and follow-up in two reference children cancer centers in Brazil / Rio de Janeiro

INTRODUCTION

sacrococcygeal teratoma (TSC) is the most common tumor of the neonatal period. Alphafetoprotein is an important tumor marker and is used in the follow-up period as a marker of malignancy. The complete surgical resection of the tumor associated with coccygectomy is the standard treatment and chemotherapy in different stages are necessary. Follow-up consists of serial exam: tumor markers, imaging searching to possible metastasis sites, in addition to a complete physical examination.

METHODOLOGY

a descriptive, retrospective, study was carried out by analyzing a chart of 25 patients of two different reference children cancer center; with TSC in the State of Rio de Janeiro from 2004 to 2019. The clinical and epidemiological data collected were described and a comparison was made between these two centers studied.

RESULTS

the sociodemographic characteristics found were similar to those described in the medical literature. Data related to treatment and follow-up, such as the use of chemotherapy, use of specific imaging tests, digital rectal examination, and outpatient follow-up, differed between the two centers studied. There was a 25% loss of follow-up.

CONCLUSION

the characteristic of being a non-cancer center can interfere with the full application of the current protocol for the treatment of sacrococcygeal teratoma. The knowledge of the data of the studied cases can allow the optimization of the approach of the patients with this pathology and generate discussions about the integral application of the specific therapeutic protocol in the medical centers that are qualified for such treatment.

Ultrasound Findings and O-RADS Malignancy Risk Stratification of Ovarian Collision Tumors

OBJECTIVES

To describe the ultrasonographic signs of ovarian collision tumors and evaluate the malignancy risk using the O-RADS system.

METHODS

This was a retrospective analysis of 25 ovarian collision tumors from 8739 patients between May 2010 and January 2020. All clinical characteristics, ultrasound images, and histological findings were collected and analyzed. Using the O-RADS lexicon descriptors, the O-RADS score was determined by two senior doctors. Lesions with O-RADS scores of 1 to 3 were classified as benign tumors, and lesions with O-RADS scores of 4 to 5 were classified as malignant tumors.

RESULTS

The mean age of the 25 patients was 30.4 years. Histological findings showed that all tumors were a combination of mature cystic teratomas and cystadenomas/cystadenocarcinomas. There were 11 benign tumors of O-RADS 2 or 3, including 3 uniocular cysts, 3 dermoid cysts, and 5 dermoid cysts with an anechoic fluid cavity. There were 12 benign tumors of O-RADS 4, including 3 uniocular-multilocular cysts with solid components, 2 multilocular cysts with irregular walls, and 8 multilocular cysts with dermoid sacs. One borderline tumor of O-RADS 4 was a multilocular cyst with irregular septation. One malignant tumor of O-RADS 5 was a multilocular cystic tumor with solid components and ascites.

CONCLUSIONS

The most common ovarian collision tumor was the coexistence of a mature cystic teratoma and a cystadenoma. The O-RADS system was able to sensitively detect malignant tumors in this series. A typical dermoid cyst with an anechoic cavity or a multilocular cyst with a dermoid sac may signify a benign collision tumor.

Treating iPSC-Derived β Cells with an Anti-CD30 Antibody-Drug Conjugate Eliminates the Risk of Teratoma Development upon Transplantation

Insulin-producing cells derived from induced pluripotent stem cells (iPSCs) are promising candidates for β cell replacement in type 1 diabetes. However, the risk of teratoma formation due to residual undifferentiated iPSCs contaminating the differentiated cells is still a critical concern for clinical application. Here, we hypothesized that pretreatment of iPSC-derived insulin-producing cells with an anti-CD30 antibody−drug conjugate could prevent in vivo teratoma formation by selectively killing residual undifferentiated cells. CD30 is expressed in all human iPSCs clones tested by flow cytometry (n = 7) but not in iPSC-derived β cells (iβs). Concordantly, anti-CD30 treatment in vitro for 24 h induced a dose-dependent cell death (up to 90%) in human iPSCs while it did not kill iβs nor had an impact on iβ identity and function, including capacity to secrete insulin in response to stimuli. In a model of teratoma assay associated with iβ transplantation, the pretreatment of cells with anti-CD30 for 24 h before the implantation into NOD-SCID mice completely eliminated teratoma development (0/10 vs. 8/8, p < 0.01). These findings suggest that short-term in vitro treatment with clinical-grade anti-CD30, targeting residual undifferentiated cells, eliminates the tumorigenicity of iPSC-derived β cells, potentially providing enhanced safety for iPSC-based β cell replacement therapy in clinical scenarios.

Characterization of stem-cell-derived islets during differentiation and after implantation

Recapitulation of embryonic pancreatic development has enabled development of methods for in vitro islet cell differentiation using human pluripotent stem cells (hPSCs), which have the potential to cure diabetes. Advanced methods for optimal generation of stem-cell-derived islets (SC-islets) has enabled successful diabetes reversal in rodents and shown promising early clinical trial outcomes. The main impediment for use of SC-islets is concern about safety because of off-target growth resulting from contaminated residual cells. In this review, we summarize the different endocrine and non-endocrine cell populations that have been described to emerge throughout β cell differentiation and after transplantation. We discuss the most recent approaches to enrich endocrine populations and remove off-target cells. Finally, we discuss the critical quality control and release criteria testing that we anticipate will be required prior to transplantation to ensure product safety.