Somatic-type malignancy (STM) can occur infrequently within a primary or metastatic testicular germ cell tumor (TGCT) and is associated with dismal prognosis and survival. STM with chondrosarcomatous features is exceedingly rare and head and neck involvement has not been previously documented. A 39-year-old white man presented with nasal obstruction and epistaxis. Imaging disclosed a 6.9-cm expansile tumor involving the nasal cavity and skull base with intraorbital and intracranial extension. The histopathologic properties of the tumor were compatible with chondrosarcoma, grade II-III. Immunohistochemically, malignant cells were strongly and diffusely positive for S100 and epithelial markers, and showed loss of SMARCB1 expression. IDH1/2 mutations were not detected. Following whole-body PET scan, a 7.0-cm left testicular mass was discovered and diagnosed as seminoma with syncytiotrophoblastic cells, stage pT3NXM1b. Extensive retroperitoneal, mediastinal, and supraclavicular lymphadenopathy was also noticed. Histopathologic examination of the left supraclavicular lymph node revealed metastatic seminoma. By FISH, most metastatic nodal seminoma cells harbored 1 to 4 copies of isochromosome 12p, while the chondrosarcoma featured duplication of 12p. Presence of a malignant TGCT with disseminated supradiaphragmatic lymphadenopathy, the unique immunophenotypic properties of the skull-based chondrosarcoma and lack of IDH1/2 aberrations with gain of 12p strongly support the diagnosis of STM chondrosarcoma arising from metastatic TGCT. The patient did not respond to chemotherapy and succumbed three months after diagnosis. Although exceedingly uncommon, metastasis to the head and neck may occur in patients with TGCT. This case of STM chondrosarcoma demonstrated divergent immunophenotypic and molecular characteristics compared to \"typical\" examples of head and neck chondrosarcoma. High index of suspicion is advised regarding the diagnosis of lesions that present with otherwise typical histomorphology but unexpected immunohistochemical or molecular features.

We report the first known case of an adrenal teratoma containing a Wilms tumor component, in a 12-month-old girl with Trisomy 21. Despite adrenal teratomas being relatively uncommon, this particular instance raises interesting questions regarding the tumor origin, given the coexistence of both a teratoma and a Wilms tumor. Two main theories of development have been hypothesized, one of which suggests that the Wilms tumor may develop from a primary teratoma and the other proposing that the teratoma could originate from a primary Wilms tumor. Our case study leans toward the former, as the majority of the tumor displayed characteristics of a typical mature teratoma, with the Wilms component discovered as an incidental finding. Successful surgical intervention led to the gross total resection of the tumor. Twelve months post-resection, the patient remains free of recurrence. This report contributes to our understanding of these rare tumor types and underlines the importance of identifying the primary tumor to ensure appropriate management and treatment.

A malignant germ cell tumor (GCT) might contain or transform into malignant non-germ cell histology, commonly referred to as somatic-type malignancy (SM). It is a rare phenomenon with poorly understood pathogenesis. SMs are mostly associated with teratomas and are mainly observed in late relapsing cases. There are no consensus guidelines on the management of SMs; however, surgery is considered to be the mainstay of treatment. Prognosis is variable depending on the time of diagnosis, site of relapse, and type of histology. Here, we present a case of a 44-year-old male with a history of mixed GCT stage IIA, initially managed with right radical orchiectomy, who developed a relapse of GCT 10 years later with an SM of adenocarcinoma subtype.

OBJECTIVE: Malignant germ cell tumours (GCTs) of the testis are rare neoplasms, but the most common solid malignancies in young men. World Health Organization guidelines divide GCTs into five types, for which numerous immunohistochemical markers allow exact histological subtyping in the majority of cases. In contrast, a germ cell origin is often hard to prove in metastatic GCTs that have developed so-called somatic malignant transformation. A high percentage, up to 89%, of GCTs are characterised by the appearance of isochromosome 12p [i(12p)]. Fluorescence in-situ hybridisation has been the most common diagnostic method for the detection of i(12p) so far, but has the disadvantages of being time-consuming, demanding, and not being a stand-alone method. The aim of the present study was to establish a quantitative real-time polymerase chain reaction assay as an independent method for detecting i(12p) and regional amplifications of the short arm of chromosome 12 by using DNA extracted from formalin-fixed paraffin-embedded tissue.
RESULTS: A cut-off value to distinguish between the presence and absence of i(12p) was established in a control set consisting of 36 tumour-free samples. In a training set of 149 GCT samples, i(12p) was detectable in 133 tumours (89%), but not in 16 tumours (11%). In a test set containing 27 primary and metastatic GCTs, all 16 tumours with metastatic spread and/or somatic malignant transformation were successfully identified by the detection of i(12p).
CONCLUSIONS: In summary, the qPCR assay presented here can help to identify, further characterise and assign a large proportion of histologically inconclusive malignancies to a GCT origin.

A 54-year-old male presented with exertional dyspnea, right massive pleural effusion, and an anterior mediastinal tumor (6.5 × 6.2 × 7.6 cm) which continued to grow during the 11-year follow-up period. Fluorodeoxyglucose positron emission tomography demonstrated a focal but remarkable uptake within the tumor mass. After chest tube drainage, the patient underwent surgical resection via a right thoracotomy. The final pathology was determined to be a mature cystic teratoma with malignant transformation to adenocarcinoma. Teratomas with somatic-type malignancy are challenging to diagnose using only preoperative evaluations. Intra-operative findings, histopathological findings, and postoperative management techniques are discussed in this report and emphasize the importance of early resection for treatment of mature teratomas, as well as the recommendation of careful inspection of pathological specimens of long-standing teratomas.

46, XY pure gonadal dysgenesis (PGD) is characterized as a female phenotype with strip-like gonads, which has a high tendency to develop into gonadal tumors. Somatic-type malignancies of germ cell tumors (SMs of GCTs) refer to the presence of malignant non-germ cell histologies admixed with GCTs, which are usually chemoresistant and indicate poor prognosis. This case report aimed to analyze the special histological type of GCTs and the importance of salvage surgery in the treatment of refractory GCTs. We report a unique case of gonadal yolk sac tumor (YST) transformed into SMs in a patient with 46, XY PGD. This 18-year-old woman underwent laparoscopic pelvic tumor resection, considered her first surgery, 2 years ago, and pathology revealed YST with initial alpha-fetoprotein (AFP) level measuring >3,000 ng/mL. She underwent seven cycles of chemotherapy, and the AFP level decreased to within a normal range after the second cycle. However, a computed tomography scan after the seventh cycle revealed abdominal and pelvic metastases, and vaginal bleeding was continuously observed. Laparoscopic exploration and laparotomy with tumor subtotal resection were performed. A pathology report showed SMs (sarcoma) derived from YST. Whole exome sequencing demonstrated that the main somatic mutation was a non-synonymous mutation of KRAS (c.182A>G), and this result did not show any indications for targeted drugs. She received three cycles of PEI (cisplatin, etoposide, and ifosfamide) chemotherapy but showed no response. She refused to undergo further treatment and has been alive with the disease for 7 months. This suggests that SMs may be one of the reasons for chemoresistance of refractory GCTs, and salvage surgery may be one of the most effective treatments for this patient. Targeted therapy may be a new choice for chemoresistant GCTs, but drug selection must be based on gene sequencing, and its efficacy still needs to be verified by further study.