[Surprising diagnosis after suspected appendicitis]. / Verrassende diagnose na verdenking appendicitis.

A 12-year-old boy presented at the emergency department because of right-sided abdominal pain. Laboratory findings and ultrasound examination were suggestive of acute appendicitis. During laparoscopy, an indurated omental mass was seen. The appendix was normal. Histopathological examination confirmed a diagnosis of omental infarction, which is rare in pediatric patients.

Unusual causes for meralgia paresthetica: systematic review of the literature and single center experience.

Meralgia paresthetica is often idiopathic, but sometimes symptoms may be caused by traumatic injury to the lateral femoral cutaneous nerve (LFCN) or compression of this nerve by a mass lesion. In this article the literature is reviewed on unusual causes for meralgia paresthetica, including different types of traumatic injury and compression of the LFCN by mass lesions. In addition, the experience from our center with the surgical treatment of unusual causes of meralgia paresthetica is presented. A PubMed search was performed on unusual causes for meralgia paresthetica. Specific attention was paid to factors that may have predisposed to LFCN injury and clues that may have pointed at a mass lesion. Moreover, our own database on all surgically treated cases of meralgia paresthetica between April 2014 and September 2022 was reviewed to identify unusual causes for meralgia paresthetica. A total of 66 articles was identified that reported results on unusual causes for meralgia paresthetica: 37 on traumatic injuries of the LFCN and 29 on compression of the LFCN by mass lesions. Most frequent cause of traumatic injury in the literature was iatrogenic, including different procedures around the anterior superior iliac spine, intra-abdominal procedures and positioning for surgery. In our own surgical database of 187 cases, there were 14 cases of traumatic LFCN injury and 4 cases in which symptoms were related to a mass lesion. It is important to consider traumatic causes or compression by a mass lesion in patients that present with meralgia paresthetica.

[Negative pressure therapy for the treatment of severe subcutaneous emphysema]. / Negatieve-druktherapie bij ernstig subcutaan emfyseem.

BACKGROUND: Subcutaneous emphysema (SE) is the presence of air in the subcutaneous tissue. In severe cases, massive SE can lead to anxiety, pain, dyspnoea and decreased eye sight due to swelling. CASE DESCRIPTION: We describe two cases, a 75-year old male and a 66-year old male, who suffered from massive SE. When conventional therapy failed, transdermal incisions and negative pressure therapy (NPT) were applied. NPT is a commonly used method for wound care. NPT resulted in a fast relief of the SE-related symptoms in both our patients. CONCLUSION: In case of severe subcutaneous emphysema, when conventional drainage is insufficient, we recommend considering making incisions followed by the use of negative pressure therapy. This can result in a rapid drainage of the subcutaneous air, with significant relief of symptoms.

Effect of minimally invasive autopsy and ethnic background on acceptance of clinical postmortem investigation in adults.

OBJECTIVES: Autopsy rates worldwide have dropped significantly over the last five decades. Imaging based autopsies are increasingly used as alternatives to conventional autopsy (CA). The aim of this study was to investigate the effect of the introduction of minimally invasive autopsy, consisting of CT, MRI and tissue biopsies on the overall autopsy rate (of CA and minimally invasive autopsy) and the autopsy rate among different ethnicities. METHODS: We performed a prospective single center before-after study. The intervention was the introduction of minimally invasive autopsy as an alternative to CA. Minimally invasive autopsy consisted of MRI, CT, and CT-guided tissue biopsies. Autopsy rates over time and the effect of introducing minimally invasive autopsy were analyzed with a linear regression model. We performed a subgroup analysis comparing the autopsy rates of two groups: a group of western-European ethnicity versus a group of other ethnicities. RESULTS: Autopsy rates declined from 14.0% in 2010 to 8.3% in 2019. The linear regression model showed a significant effect of both time and availability of minimally invasive autopsy on the overall autopsy rate. The predicted autopsy rate in the model started at 15.1% in 2010 and dropped approximately 0.1% per month (ß = -0.001, p < 0.001). Availability of minimally invasive autopsy increased the overall autopsy rate by 2.4% (ß = 0.024, p < 0.001). The overall autopsy rate of people with an ethnic background other than western-European was significantly higher in years when minimally invasive autopsy was available compared to when it was not (22/176 = 12.5% vs. 81/1014 (8.0%), p = 0.049). CONCLUSIONS: The introduction of the minimally invasive autopsy had a small, but significant effect on the overall autopsy rate. Furthermore, the minimally invasive autopsy appears to be more acceptable than CA among people with an ethnicity other than western-European.

Incidence of testicular tumor subtypes according to the updated WHO classification, North Rhine-Westphalia, Germany, 2008-2013.

BACKGROUND: In 2016, the WHO introduced an updated classification for testicular tumors. The application of this updated classification to cancer registry data requires some recoding of tumors. OBJECTIVES: The aim of this study was to provide up-to-date population-based incidence estimates of subtypes of testicular germ cell tumors (TGCT) according to the updated classification. MATERIAL AND METHODS: We reviewed 2251 pathology reports (42.9%) out of 5252 testicular tumors at the cancer registry of North Rhine-Westphalia for the years 2008-2013. We used population counts to estimate age-standardized incidence rates per million person-years (EUROSTAT revised European Standard Population). RESULTS: The application of the updated WHO classification resulted in a recoding of 8.9% of all testicular tumors. While the recodings have no influence on the incidence of seminomatous and non-seminomatous TGCTs that include mixed TGCTs, they influence the incidence of individual histological types of seminomatous and non-seminomatous TGCTs. Among the 4935 testicular germ cell tumors (TGCT), 23.7% were mixed TGCTs. Overall, 46.9% of all mixed TGCTs included seminoma and age-standardized incidence rates were highest for the combination seminoma plus embryonal carcinoma (5.9 per million person-years) and embryonal carcinoma plus teratoma (4.9 per million person-years). The median age at diagnosis was higher for mixed TGCTs including seminoma (31 years) than those that did not include seminoma (28 years). DISCUSSION AND CONCLUSIONS: Population-based incidence time trends for seminomatous and non-seminomatous TGCTs that include mixed TGCTs are not distorted by the introduction of the WHO update. Trend distortions can only be expected if time trends of individual histological subtypes of the seminomatous and non-seminomatous TGCTs are examined.

Early Consequences of Pectus Excavatum Surgery on Self-Esteem and General Quality of Life.

BACKGROUND: An early observation after chest wall correction is direct inspection from the PE patient of their "new" thorax. Changes in self-perception may give raise to other psychological adaptations. The aim of this study was to evaluate the early changes in the fields of self-esteem, body image and QoL. METHODS: Prospective observational longitudinal multicenter cohort study. Self-esteem, emotional limitations and general health were assessed using the Child Health Questionnaire (CHQ) in patients under 18 and the World Health Organization Quality of Life Questionnaire-bref (WHOQOL-bref) was used for body image, psychological domain and overall QoL in patients over 16 years of age. Measurements were taken before surgery (T1) and 6 weeks (T2), and 6 months thereafter (T3). RESULTS: Scores on post-operative self-esteem were significantly higher compared with scores pre-operatively (p < 0.007). Also body image, psychological domain and emotional limitations showed significant improvement, respectively p < 0.001, p < 0.001, and p < 0.016. Significant improvement in the first three components was mainly achieved in the first 6 weeks post-operative. In emotional limitation, however, the largest change was between 6 weeks and 6 months. Overall quality of life in the WHOQOL-bref and general health domain in the CHQ showed no significant improvement in relation to the pre-operative scores. CONCLUSION: Post-operative PE patients after Nuss procedure showed an improved body image, increased self-esteem and increased psychological resilience in the first 6 months, with the most marked change in the first 6 weeks. Also emotional limitations changed significantly over time. The changes were not large enough to influence general QoL or general health significantly.

Malignant testicular germ cell tumors in postpubertal individuals with androgen insensitivity: prevalence, pathology and relevance of single nucleotide polymorphism-based susceptibility profiling.

STUDY QUESTION: What is the prevalence of malignant testicular germ cell tumors (TGCT) and its precursors, (pre-) germ cell neoplasia in situ (GCNIS), in late teenagers and adults who have androgen insensitivity syndrome (AIS) and the impact of an individual's genetic susceptibility to development of TGCT? SUMMARY ANSWER: No GCNIS or TGCT was diagnosed, but pre-GCNIS was identified in 14 and 10% of complete and partial AIS patients, respectively, and was associated with a higher genetic susceptibility score (GSS), with special attention for KITLG (rs995030) and ATFZIP (rs2900333). WHAT IS KNOWN ALREADY: Many adult women with AIS decline prophylactic gonadectomy, while data regarding the incidence, pathophysiology and outcomes of TGCT in postpubertal individuals with AIS are lacking. The relevance of genetic factors, such as single nucleotide polymorphisms (SNPs), in predisposing AIS individuals to TGCT is unknown. STUDY DESIGN, SIZE, DURATION: This multicenter collaborative study on prophylactically removed gonadal tissue was conducted in a pathology lab specialized in germ cell tumor biology. PARTICIPANTS/MATERIALS, SETTING, METHODS: Material from 52 postpubertal individuals with molecularly confirmed AIS (97 gonadal samples) was included; the median age at surgery was 17.5 (14-54) years. Immunohistochemical studies and high-throughput profiling of 14 TGCT-associated SNPs were performed. The main outcome measures were the prevalence of pre-GCNIS, GCNIS and TGCT, and its correlation with a GSS, developed based on the results of recent genome-wide association studies. MAIN RESULTS AND ROLE OF CHANCE: The earliest recognizable change preceding GCNIS, referred to as pre-GCNIS, was present in 14% of individuals with complete and 10% of those with partial AIS at a median age of 16 years. No GCNIS or invasive TGCT were found. The median GSS was significantly greater for those with, compared to those without, pre-GCNIS (P = 0.01), with an overlap between groups. Our data suggest important roles for risk alleles G at KITLG (rs995030) and C at ATFZIP (rs2900333), among the 14 studied TGCT-associated SNPs. LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: A limited number of cases were included. WIDER IMPLICATIONS OF THE FINDINGS: Our data suggest that the prevalence of pre-GCNIS in individuals with AIS beyond puberty is around 15%. Genetic susceptibility likely contributes to pre-GCNIS development in AIS but factors related to malignant progression remain unclear. Although data in older patients remain scarce, malignant progression appears to be a rare event, although the natural history of the premalignant lesion remains unknown. Therefore, the practice of routine prophylactic gonadectomy in adults with AIS appears questionable and the patient's preference, after having been fully informed, should be decisive in this matter. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by research grants from the Research Foundation Flanders (FWO) (to M.C.), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq G0D6713N) (to B.B.M. and M.C.) and the European Society for Pediatric Endocrinology (ESPE), granted by Novo Nordisk AB (to J.K.). There are no competing interests.

Immunohistochemical expression of stem cell markers in pheochromocytomas/paragangliomas is associated with SDHx mutations.

OBJECTIVE: Pheochromocytomas (PCCs) are neuroendocrine tumors that occur in the adrenal medulla, whereas paragangliomas (PGLs) arise from paraganglia in the head, neck, thorax, or abdomen. In a variety of tumors, cancer cells with stem cell-like properties seem to form the basis of tumor initiation because of their ability to self-renew and proliferate. Specifically targeting this small cell population may lay the foundation for more effective therapeutic approaches. In the present study, we intended to identify stem cells in PCCs/PGLs. DESIGN: We examined the immunohistochemical expression of 11 stem cell markers (SOX2, LIN28, NGFR, THY1, PREF1, SOX17, NESTIN, CD117, OCT3/4, NANOG, and CD133) on tissue microarrays containing 208 PCCs/PGLs with different genetic backgrounds from five European centers. RESULTS: SOX2, LIN28, NGFR, and THY1 were expressed in more than 10% of tumors, and PREF1, SOX17, NESTIN, and CD117 were expressed in <10% of the samples. OCT3/4, NANOG, and CD133 were not detectable at all. Double staining for chromogranin A/SOX2 and S100/SOX2 demonstrated SOX2 immunopositivity in both tumor and adjacent sustentacular cells. The expression of SOX2, SOX17, NGFR, LIN28, PREF1, and THY1 was significantly associated with mutations in one of the succinate dehydrogenase (SDH) genes. In addition, NGFR expression was significantly correlated with metastatic disease. CONCLUSION: Immunohistochemical expression of stem cell markers was found in a subset of PCCs/PGLs. Further studies are required to validate whether some stem cell-associated markers, such as SOX2, could serve as targets for therapeutic approaches and whether NGFR expression could be utilized as a predictor of malignancy.

Pediatric germ cell tumors presenting beyond childhood?

Four cases are reported meeting the criteria of a pediatric (i.e., Type I) testicular germ cell tumor (TGCT), apart from the age of presentation, which is beyond childhood. The tumors encompass the full spectrum of histologies of pediatric TGCT: teratoma, yolk sac tumor, and various combinations of the two, and lack intratubular germ cell neoplasia/carcinoma in situ in the adjacent parenchyma. The neoplasms are (near)diploid, and lack gain of 12p, typical for seminomas and non-seminomas of the testis of adolescents and adults (i.e., Type II). It is proposed that these neoplasms are therefore late appearing pediatric (Type I) TGCT. The present report broadens the concept of earlier reported benign teratomas of the post-pubertal testis to the full spectrum of pediatric TGCT. The possible wide age range of pediatric TGCT, demonstrated in this study, lends credence to the concept that TGCT should according to their pathogenesis be classified into the previously proposed types. This classification is clinically relevant, because Type I mature teratomas are benign tumors, which are candidates for testis conserving surgery, as opposed to Type II mature teratomas, which have to be treated as Type II (malignant) non-seminomas.

Excellent prognosis of node negative patients after sentinel node procedure in colon carcinoma: a 5-year follow-up study.

AIM: Investigate the prognostic impact and clinical relevance of the sentinel node (SN)-procedure in colon carcinoma. PATIENTS AND METHODS: Between May 2002 and January 2004, the SN-procedure was performed in 55 patients that underwent elective resection for clinically non-advanced colon carcinoma. A control group of 110 patients was identified from a cohort between January 2000 and April 2002. All lymph nodes were analysed by conventional haematoxylin-eosin staining. All negative SNs underwent in-depth analysis using immunohistochemical-staining and automated microscopy with the Ariol-system. Patients with positive lymph nodes were offered adjuvant chemotherapy. All patients were routinely monitored at 6-month intervals and follow-up was more than 5 years. RESULTS: The SN was successfully identified in 98% of the patients, with 94% sensitivity. In-depth analysis with immunohistochemistry and automated microscopy (Ariol-system) upstaged 3 and 4 patients respectively. When only node-negative patients were analysed, overall 5-year-survival was significantly better in the SN group (91% vs. 76%, p = 0.04). Cancer-specific-mortality was even 0% (vs. 8%, p = 0.08). Disease-free-survival was significantly improved to 96% (vs. 77%, p < 0.01). CONCLUSIONS: This study describes the prognostic impact of the SN-procedure in colon carcinoma after 5-year-follow-up. Only one patient had recurrent disease after a negative SN procedure (disease-free-survival 96%). These results indicate that the SN-procedure is of prognostic relevance and might be useful to select patients for adjuvant chemotherapy. Patients that are lymph node negative after an SN-procedure have an excellent prognosis and do not need adjuvant treatment.

45,X/46,X,psu dic(Y) gonadal dysgenesis: influence of the two cell lines on the clinical phenotype, including gonadal histology.

A child born with ambiguous genitalia (Prader III) was found to have a 45,X[92.2%]/46,X,psu dic(Y)(p12)[7.8%] karyotype in peripheral blood lymphocytes. The testosterone level was consistent with that of a normal male; however, gonadotropins were elevated. Ultrasound and endoscopy of the urogenital sinus revealed well-developed Müllerian structures. At 3.5 months, the child was operated for right-sided incarcerated hernia, and the gonad situated at the inguinal region was biopsied and classified as primitive testis. Based on the presence of Müllerian structures, anatomy of external genitalia and wish of the parents, the child was assigned female gender. She underwent removal of the left gonad at 4 months during another acute surgery; histology was similar to the right gonad. The rest of the right gonad was removed at 16 months, and feminizing genitoplasty took place at 3 years. The right and left gonad contained 28 and 22% of cells with a Y chromosome, respectively. During further histological examination, dysgenetic features of the gonads were discovered. Some germ cells displayed abnormal development based on the specific expression of immunohistochemical markers (OCT3/4, TSPY, KITLG), indicating a possible risk for future malignant germ cell tumor development. Contribution of the 45,X cell line to the phenotype was also observed: the patient developed celiac disease, and her growth pattern resembled that of Turner syndrome responding to growth hormone treatment.

Spinal reconstruction with free vascularised bone grafts; approaches and selection of acceptor vessels.

The use of free vascularised bone grafts is an infrequently performed surgical technique for the reconstruction of spinal defects. This field of surgery brings many challenges concerning the choice of free vascularised bone graft, planning of the operative procedure and selection of recipient vessels. This study aims to report our experience with free vascularised bone grafts, with special emphasis on the surgical approach and the selection of recipient vessels. Over a period of 17 years (1994-2011), we used these grafts for anterior spinal reconstruction in 30 patients. In 28 patients, a free vascularised fibular graft was used, and in two cases a free vascularised iliac crest graft was used. The spinal segments reconstructed involved the cervical or cervicothoracic spine (6 cases), the thoracic spine (11 cases) and the thoracolumbar and lumbosacral spine (13 cases). Revascularisation of the free vascularised bone graft proved to be technically feasible in 30 patients, but failed in one fibular graft due to difficulties with recipient vessels in the lumbar region. Technical challenges were met with respect to the choice of the recipient vessel at various anatomical sites. Availability of acceptor vessels was highly de-pendant of the type of surgery (resection or stabilisation) and the selected surgical approach. Based on these findings, a preferred approach is given for each region. The use of free vascularised bone grafts is a valuable technique for the reconstruction of complex spinal disorders. Successful execution requires microvascular expertise with respect to graft harvesting and appropriate choice of recipient vessels. Adequate preoperative planning in a multidisciplinary setting and adherence to the basic principles for spinal reconstruction are required.

Stage I-II non-small-cell lung cancer treated using either stereotactic ablative radiotherapy (SABR) or lobectomy by video-assisted thoracoscopic surgery (VATS): outcomes of a propensity score-matched analysis.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) lobectomy and stereotactic ablative radiotherapy (SABR) are both used for early-stage non-small-cell lung cancer. We carried out a propensity score-matched analysis to compare locoregional control (LRC). PATIENTS AND METHODS: VATS lobectomy data from six hospitals were retrospectively accessed; SABR data were obtained from a single institution database. Patients were matched using propensity scores based on cTNM stage, age, gender, Charlson comorbidity score, lung function and performance score. Eighty-six VATS and 527 SABR patients were matched blinded to outcome (1:1 ratio, caliper distance 0.025). Locoregional failure was defined as recurrence in/adjacent to the planning target volume/surgical margins, ipsilateral hilum or mediastinum. Recurrences were either biopsy-confirmed or had to be PET-positive and reviewed by a tumor board. RESULTS: The matched cohort consisted of 64 SABR and 64 VATS patients with the median follow-up of 30 and 16 months, respectively. Post-SABR LRC rates were superior at 1 and 3 years (96.8% and 93.3% versus 86.9% and 82.6%, respectively, P = 0.04). Distant recurrences and overall survival (OS) were not significantly different. CONCLUSION: This retrospective analysis found a superior LRC after SABR compared with VATS lobectomy, but OS did not differ. Our findings support the need to compare both treatments in a randomized, controlled trial.

Trimodality therapy for superior sulcus tumours: evolution and evaluation of a treatment protocol.

AIM: We studied the clinical outcomes of a trimodality protocol used for the treatment of superior sulcus tumours (SST) in a tertiary referral centre. METHODS: The details of all patients who underwent treatment for a SST between January 2003 and December 2009 were retrospectively analysed. Following pre-treatment staging, all patients underwent concurrent chemoradiotherapy with cisplatin/etoposide, followed by surgery. Outcomes studied were treatment-related complications, pathological response rates, recurrence rates and survival. RESULTS: Fifty-four patients were treated by chemotherapy (cisplatin/etoposide) and concurrent radiotherapy (46-66 Gy) followed by surgical resection. Minimum follow-up was 23 months. No 30-day mortality was observed. A complete (R0) resection was performed in 44 out of 54 patients. None had an R2 resection. Two-year survival was 50% (95%CI: 36.7-63.3). Patients who achieved a pathological complete response (n = 16) had a 2-year survival of 81% (95%CI: 62.1-100.0) versus a 37% 2-year survival (95%CI: 21.5-52.1) in patients with remaining vital tumour in their resection specimens (n = 38; P = 0.003). Five patients developed a local recurrence, and 23 patients a distant metastasis, mainly to the brain (n = 15). Two patients died from causes unrelated to cancer. CONCLUSIONS: Trimodality treatment of SST in accordance to our protocol achieved results comparable to previous reports. Pathological response rates to induction were an important prognostic factor, and distant metastasis remains a major problem.

Maintaining success, reducing treatment burden, focusing on survivorship: highlights from the third European consensus conference on diagnosis and treatment of germ-cell cancer.

In November 2011, the Third European Consensus Conference on Diagnosis and Treatment of Germ-Cell Cancer (GCC) was held in Berlin, Germany. This third conference followed similar meetings in 2003 (Essen, Germany) and 2006 (Amsterdam, The Netherlands) [Schmoll H-J, Souchon R, Krege S et al. European consensus on diagnosis and treatment of germ-cell cancer: a report of the European Germ-Cell Cancer Consensus Group (EGCCCG). Ann Oncol 2004; 15: 1377-1399; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part I. Eur Urol 2008; 53: 478-496; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part II. Eur Urol 2008; 53: 497-513]. A panel of 56 of 60 invited GCC experts from all across Europe discussed all aspects on diagnosis and treatment of GCC, with a particular focus on acute and late toxic effects as well as on survivorship issues. The panel consisted of oncologists, urologic surgeons, radiooncologists, pathologists and basic scientists, who are all actively involved in care of GCC patients. Panelists were chosen based on the publication activity in recent years. Before the meeting, panelists were asked to review the literature published since 2006 in 20 major areas concerning all aspects of diagnosis, treatment and follow-up of GCC patients, and to prepare an updated version of the previous recommendations to be discussed at the conference. In addition, ∼50 E-vote questions were drafted and presented at the conference to address the most controversial areas for a poll of expert opinions. Here, we present the main recommendations and controversies of this meeting. The votes of the panelists are added as online supplements.

Gonadal and extragonadal germ cell tumours in the United States, 1973-2007.

Germ cell tumours (GCTs) most often arise in the gonads, but some develop extragonadally. The aim of this study was to examine gender- and race-specific trends in incidence and survival of gonadal (GGCTs) and extragonadal GCTs (EGCTs) in the US from 1973 to 2007. We also examined the topographical distribution of EGCTs by race and gender. We estimated age-specific and age-standardized incidence rates and 5-year relative survival rates (RSR) of GCTs using the Surveillance, Epidemiology and End Results (SEER) Program (SEER nine registries). GCTs and their topographical sites were identified using ICD-O morphology and topography codes. Of 21,170 GCTs among males, 5.7% were extragonadal (Whites 5.5%; Blacks 16.3%). Of 2093 GCTs among females, 39.3% were extragonadal (Whites, 36.9%; Blacks 51.0%). The incidence of GGCT was much higher among White (56.3/1,000,000) than Black males (10.0/1,000,000), while there was no difference in incidence between White and Black females (3.2/1,000,000). The rates of EGCT among men and women of both races were similar (range:1.9-3.4/1,000,000). The most frequent extragonadal sites were mediastinum among males and placenta among females. The 5-year RSR of testicular GCT was higher among Whites (97%) than Blacks (90%), as was the 5-year RSR of ovarian GCT (Whites, 92%; Blacks 85%). In general, the 5-year RSRs of EGCTs were lower than the 5-year RSRs of GGCTs. The different incidence trends of GGCTs and EGCTs and distinct age-specific incidence patterns by anatomical site of EGCTs suggest that GGCTs and EGCTs may have different aetiologies.

Clinical applications of FDG-probe guided surgery.

BACKGROUND: For a definitive diagnosis in many oncological, inflammatory and infectious diseases histological examination is required. Non-palpable lesions detected with PET/CT scanning that cannot be localized with conventional imaging methods can be localized and excised using FDG-probe guided surgery. We describe the application of FDG-probe guided surgery in 9 patients. METHODS: The application of FDG-probe guided surgery used in 9 consecutive patients with oncological and infectious diseases is described. Four hours before surgery, 3.5 MBq/Kg body weight FDG was intravenously administered after which a FDG-PET-scan was performed to confirm the FDG-avid lesion(s). The lesions with highest activity were detected with the FDG-probe and the lesions were subsequently excised and sent for histopathological examination. RESULTS: In all of the 9 cases the target lesion was successfully identified and subsequently removed. When multiple and/or macroscopically normal lymph nodes were found, the use of the FDG-probe allowed selection of the PET-avid lymph nodes for resection. CONCLUSION: FDG-probe guided surgery is a relatively simple surgical technique to identify and excise FDG-accumulating suspicious lesions in oncological, inflammatory and infectious diseases.

Gonadal development and tumor formation at the crossroads of male and female sex determination.

Malignant germ cell tumor (GCT) formation is a well-known complication in the management of patients with a disorder of sex development (DSD). DSDs are defined as congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. DSD patients in whom the karyotype - at least at the gonadal level - contains (a part of) the Y chromosome are at increased risk for neoplastic transformation of germ cells, leading to the development of the so-called 'type II germ cell tumors'. However, tumor risk in the various forms of DSD varies considerably between the different diagnostic groups. This contribution integrates our actual knowledge on the pathophysiology of tumor development in DSDs, recent findings on gonadal (mal)development in DSD patients, and possible correlations between the patient's phenotype and his/her risk for germ cell tumor development.

A pathologist's view on the testis biopsy.

Aspects of the biopsy of the testis from the pathologist's point of view are discussed. Direct enzyme-histochemical staining for alkaline phosphatase (dAP) on frozen sections of biopsies taken during operation is a useful diagnostic tool to aid surgeons in testis-sparing surgery. Biopsy of the contralateral testis for the diagnosis of carcinoma in situ (CIS) in patients with a testicular germ cell tumour is not standard of care in most countries because of the high rate of negative biopsies. Based on risk factors for germ cell tumours, i.p. microlithiasis, a patient population is defined in which the rate of CIS in the contralateral biopsy is about 25%. It is reiterated that the diagnosis of CIS in testicular biopsies requires expertise, and should not be carried out without immunohistochemistry for markers for CIS. As OCT3/4 is increasingly used as marker, it is important to be aware that it may be false-negative in biopsies fixed in Bouin's or Stieve's fixative. Preliminary results are presented on a series of biopsies from cryptorchid testes in infants and children allowing the definition of morphological and immunohistochemical criteria for delayed maturation of gonocytes and pre-CIS.