Primary peripheral primitive neuroectodermal tumor/Ewing's tumor of the testis in a 46-year-old man—differential diagnosis and review of the literature

Urinary cytologic features of primitive neuroectodermal tumor primarily involving the kidney: A case report

Renal primitive neuroectodermal tumor(rPNET) is an extremely rare and distinct entity that can be mistaken for a variety of other round cell tumors. Findings from fine needle aspiration cytology have been reported, but there have been no reports of PNET cytomorphological features in urine cytology specimen. Here, we report a case of PNET characterized by urine cytology. A 24-year-old girl presented with hematuria for half a month. Computed tomography showed a large tumor involving the upper pole of the right kidney. Urinary cytology exhibited highly cellular clusters composed of small, round, atypical cells with little cytoplasm and a high nuclear/cytoplasmic ratio. Following a right nephrectomy, the biopsy confirmed the diagnosis of rPNET. Additionally, immunohistochemistry (IHC) staining of the decolorized liquid-based cytology slide was positive for CD99, further confirming the diagnosis through urine cytology. Our observations suggest that urinary cytology in combination with cytological morphology and immunocytochemistry may be a potentially useful method for the detection of PNET.

Paratesticular Ewing's sarcoma

This case report follows a 23-year-old man who presented with a painful right scrotal mass which was found to be a paratesticular vascular solid mass on ultrasound, and after uncomplicated orchiectomy, was revealed to be a high-grade extraskeletal Ewing's sarcoma. Diagnosis leading up to the orchiectomy was primarily clinical with only ultrasound used in identification and characterization of the paratesticular mass. Paratesticular masses are more commonly benign, and ultrasound is the first modality, with computed tomography and magnetic resonance imaging providing more definitive findings. We discuss imaging findings and histopathology of this rare tumor with an uncommon presentation.

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.

News in the classification of WHO 2022 testicular tumours

The novelties in WHO 5^th edition classification of genitourinary tumours are: a) nomenclature changes, including the replacement of the term "primitive neuroectodermal tumour" with "embryonic-type neuroectodermal tumour" and of "carcinoid" with "neuroendocrine tumour". Also, seminoma is now placed in a "germinoma" family of tumours, while sertoliform cystoadenoma was moved from adnexal tumours to Sertoli cell tumours; b) new entities, specifically signet ring stromal tumour, myoid gonadal stromal tumour and well-differentiated papillary mesothelial tumour.

Penis as a primary site of an extraskeletal Ewing sarcoma: A case report

RATIONALE

The Ewing sarcoma family of malignant tumors is a group of tumors characterized by morphologically similar round-cell neoplasms and by the presence of a common chromosomal translocation; Ewing sarcoma family of tumors typically occur in children and young adults between 4 to 15 years of age. The primary tumor usually originates in the bone, extraskeletal localization is rare.

PATIENT CONCERN

We present a case report concerning a 32-year-old male patient with a primary involvement of the penis.

DIAGNOSIS

The histopathology from the first penile biopsy showed a small-cell neuroendocrine carcinoma; however, that result was based on a sample obtained at a different facility than the Sarcoma Center, where the investigating pathologist did not have the adequate expertise. The patient then underwent a radical penectomy and a second reading of the histology was demanded after a radical penile amputation when Ewing sarcoma with R1 resection was confirmed.

INTERVENTIONS

The patient was referred to the national Sarcoma Center, where - using a multidisciplinary approach - the treatment was started with curative intent. However, it was preceded by a non-standard initiation of the therapy due to the poor primary diagnosis.

OUTCOMES

The non-standard therapy at the onset of the disease caused a poor prognosis of an otherwise curable diagnosis. Despite all that, the patient survived for a relatively long time.

LESSONS

The treatment of sarcomas with atypical localizations should be conducted by an experienced multidisciplinary team in a center with experience in sarcoma treatment.

Peripheral primitive neuroectodermal tumor associated with paraneoplastic Cushing's syndrome: The rare case

Introduction

Primitive neuroectodermal tumors (PNET) form a group of tumors defined by their appearance that are thought to develop from primitive (undifferentiated) nerve cells in the brain. They are rare tumors and their incidence is not well defined.

Case presentation

An 18-month-old male presenting with typical Cushingoid appearance (moon face, central obesity, hirsutism and growth arrest) was admitted for evaluation of endocrine problems. Subsequent laboratory studies revealed markedly elevated adrenocorticotropic (ACTH) and cortisol levels, as well as a hypokalemic metabolic alkalosis, these data are consistent with the diagnosis of Cushing's disease. He was treated with metyrapone to control hypercortisolemia. One month and a half later, a mass was detected in the abdomen by ultrasonography. An abdominal Computed tomography confirmed a large heterogeneous retroperitoneal mass with a significant amount of extension into surrounding structures which was removed by laparoscopic abdominal surgery. The patient's symptoms completely resolved and the ACTH and cortisol levels were also greatly reduced. Histologically, the tumor tissue consistent with the diagnosis of the retroperitoneal primitive neuroectodermal tumor which was confirmed immunohistochemically. This case demonstrates the successful diagnosis and treatment of a rare neoplasm.

Conclusion

This is the first rare case with ectopic ACTH syndrome caused by the peripheral primitive neuroectodermal tumor.

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Paraneoplastic Cushing's syndrome has been attributed to ectopic ACTH secretion.

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Primitive neuroectodermal tumor secret ectopic ACTH and make Cushing's syndrome.

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Our case is an 18-month-old male presenting Cushing's syndrome because of retroperitoneal primitive neuroectodermal tumor.

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After remove of tumor,the patient's symptoms completely resolved.

Ewing sarcoma with extensive neural differentiation: a clinicopathologic, immunohistochemical, and molecular analysis of three cases

OBJECTIVES

Three patients with Ewing sarcomas showing extensive neural differentiation are presented.

METHODS

The patients were two women and one man between the ages of 15 and 35 years. Anatomically, one tumor was in the lung, one in the testis, and one in the cervix uteri. The symptoms were determined by the location of the neoplasm and included respiratory symptoms, testicular pain, and pelvic manifestations, respectively. Complete surgical resection of the tumors was performed.

RESULTS

Histologically, all neoplasms showed similar characteristics-namely, a neoplastic cellular proliferation arranged in sheets and composed of small blue cells with round to oval nuclei and inconspicuous nucleoli typical for Ewing sarcoma. In addition, in two cases, there were areas characterized by the presence of neuropil, ganglion cells, and small cells most compatible with ganglioneuroblastoma, while in one tumor, the neural component was characterized by the presence of small cells with prominent perivascular pseudorosettes more closely resembling ependymoma. Immunohistochemical studies in all cases and molecular analysis in two tumors were in keeping with a diagnosis of Ewing sarcoma.

CONCLUSIONS

The recognition of such histologic variants is important in the diagnostic assessment of these tumors to avoid misinterpretation, especially in small biopsy specimens.

Peripheral primitive neuroectodermal tumor of the parotid gland in a child: A case report

Primitive neuroectodermal tumor (PNET) is a term used to describe a group of highly malignant neoplasms of soft-tissue origin, with varying degrees of divergent differentiation. The occurrence of peripheral PNET in the head and neck region has been reported infrequently in the medical literature. This disease generally occurs in adolescents and young adults, and rarely occurs in children <3 years old. The current study presents an extremely rare case of pPNET of the parotid gland in a 2-year-old male, which had been previously misdiagnosed and treated as a mumps. The lesion showed the characteristic histological features of pleomorphic cellular infiltrate with hyperchromatic small cells scattered in the fibrovascular stroma, interposed by fibrous septa and Homer-Wright rosettes. Positive immunohistochemical staining for CD99 and vimentin was detected. The patient was treated with chemotherapy and radiotherapy following surgical removal, and has been under close observation since the treatment (approximately seven months), with no signs of recurrence. The clinical history and radiological and histopathological findings are presented, together with the immunoreactivity of this tumor.

Spermatocytic seminoma with neuroectodermal differentiation and sertoli cell tumor in a dog

Two distinct nodules developed in a cryptorchid testis of an 8-year-old male West Highland White Terrier. One nodule was a Sertoli cell tumor. The other was a spermatocytic seminoma with focal primitive neuroectodermal differentiation: formation of Homer-Wright rosettes and perivascular pseudorosettes, with immunoreactivity for S-100 protein, neuron-specific enolase, synaptophysin, neurofilament-68 kDa, microtubule-associated protein 2, and vimentin. The dog was alive and healthy 2 years after castration.