1,721,008 research outputs found
Pathogenesis and pathobiology of testicular germ cell tumours: a view from a developmental biological perspective with guidelines for pathological diagnostics
No full textTesticular germ cell tumours (GCT) are divided into three different subtypes (types I–III) regarding to their developmental origin, histological differences and molecular features. Type I GCT develop from disturbed primordial germ cells and most commonly occur in children and young adolescents, which is why they are referred to as prepubertal GCT. Type II GCT develop from a non‐invasive germ cell neoplasia in situ (GCNIS) and show an isochromosome 12p (i12p) or gain of 12p material as a common and characteristic molecular alteration. Type III GCT originate from distorted postpubertal germ cells (e.g. spermatogonia) in adult patients and have changes on chromosome 9 with amplification of the DMRT1 gene. Type I GCT encompass prepubertal‐type teratomas and yolk‐sac tumours (YST). Type II GCT include seminoma, embryonal carcinoma, choriocarcinoma, postpubertal‐type teratoma and postpubertal‐type YST. Types I and II GCT both show similar morphology, but are separated from each other by the detection of a GCNIS and an i12p in type II GCT. For type II GCT it is especially important to detect non‐seminomatous elements, as these tumours have a worse biological behaviour and need a different treatment to seminomas. In contrast to types I and II GCT, type III tumours are equivalent to spermatocytic tumours and usually occur in elderly men, with few exceptions in young adults. The development of types I and II GCT seems to depend not upon driver mutations, but rather on changes in the epigenetic landscape. Furthermore, different pluripotency associated factors (e.g. OCT3/4, SOX2, SOX17) play a crucial role in GCT development and can be used as immunohistochemical markers allowing to distinguish the different subtypes from each other in morphologically challenging tissue specimens. Especially in metastatic sites, a morphological and immunohistochemical diagnostic algorithm is important to detect small subpopulations of each non‐seminomatous GCT subtype, which are associated with a poorer prognosis and need a different treatment. Furthermore, primary extragonadal GCT of the retroperitoneum or mediastinum develop from misguided germ cells during embryonic development, and might be challenging to detect in small tissue biopsies due to their rarity at corresponding sites. This review article summarises the pathobiological and developmental aspects of the three different types of testicular GCT that can be helpful in the histopathological examination of tumour specimens by pathologists.Wilhelm Sander-Stiftung https://doi.org/10.13039/10000867
New 2022 WHO classification of testicular tumours
No full textIn der 5. Edition der WHO-Klassifikation für Tumoren der ableitenden Harnwege und des männlichen Genitaltraktes gab es einige Neuerungen der bestehenden Klassifikationen. Sie werden in diesem Artikel zusammengefasst und betreffen u. a. die Bezeichnungen neuroektodermaler und neuroendokriner Tumoren des Hodens. Daneben wurden der siegelringzellige Stromatumor und der myoidale Gonadenstromatumor als eigenständige Entitäten der Gonadenstromatumoren eingeführt. Außerdem wurden jeweils gemeinsame Kapitel für hämatolymphoide Neoplasien sowie Weichgewebstumoren der ableitenden Harnwege und des männlichen Genitaltraktes geschaffen.The 5th edition of the WHO Classification of Tumours: Urinary and Male Genital Tumours includes some important revisions of the testicular tumour classifications, which are summarized in this article. They concern, for example, the definition of tumours of neuroectodermal and neuroendocrine origin. Furthermore, signet-ring stromal tumours and myoid gonadal stromal tumours are listed as separate entities in the section about sex-cord stromal tumours. Moreover, lymphatic neoplasia as well as soft tissue tumours of the urinary and male genital tract are each combined in a common section
Histopathologische Befundung von Keimzelltumoren – worauf ist zu achten?
No full textZusammenfassung Die Keimzelltumoren machen den Großteil der Hodentumoren aus und bilden eine heterogene Gruppe an Tumoren, die sich biologisch unterschiedlich verhalten. Aufgrund des Auftretens in unterschiedlichen Altersgruppen, ihrer morphologischen Charakteristika und der molekularen Veränderungen werden sie in 3 verschiedene Gruppen (Typ I–III) unterteilt. Die genaue histopathologische Analyse eines Orchiektomieresektats, die Zuordnung in die genannten 3 Gruppen und die genaue Benennung aller Subtypen mit prozentualer Verteilung ist für die Therapie und Prognose eines Patienten mit Keimzelltumor sehr wichtig. In diesem Artikel wird die Vorgehensweise bei der Aufarbeitung eines Orchiektomieresektats und die histopathologische Analyse des Hodentumorgewebes geschildert und dargestellt, in welchen Situationen Hilfsmittel wie immunhistochemische oder molekularpathologische Untersuchungen notwendig sind. Ferner wird die aktuelle Einteilung der Keimzelltumoren des Hodens anhand der gültigen WHO-Klassifikation geschildert und diskutiert
Primary germ cell tumours of the mediastinum: A review with emphasis on diagnostic challenges
No full textThis article will review current aspects of the histopathological, immunohistochemical and molecular analysis of primary mediastinal germ cell tumours (PMGCTs) as well as their aetiological, epidemiological, clinical and therapeutic features. PMGCTs represent an important differential diagnosis in the spectrum of mediastinal tumours, and their diagnosis is usually made on small tissue samples from core needle biopsies in combination with diagnostic imaging and serum tumour markers. As in lymphomas, a small biopsy is often the only viable tumour sample available from these patients, as they receive chemotherapy prior to eventual surgical resection. Pathologists therefore need to apply an efficient combination of immunohistochemical markers to confirm the diagnosis of a PMGCT and to exclude morphological mimics
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