The role of thoracic surgery in the management of complicated acute and post-acute COVID-19 pneumonia (PASC).

INTRODUCTION: COVID-19 is considered a respiratory virosis in its classic form, although it may present with heterogeneous symptoms. Thoracic complications occur in a small percentage of patients. Our objective was to evaluate existing experience with this disease and its thoracic manifestations and to determine the real-world status of care of these patients. METHODS: This study is a retrospective, single-institution analysis of a group of patients hospitalized with acute and post-acute COVID-19 pneumonia at Thomayer Hospital in Prague in the period from December 2020 to March 2022 and indicated for a thoracic surgical procedure. RESULTS: During the peak of COVID-19 pandemic, a thoracic intervention was performed in 46 admitted patients. Thoracic drainage (due to pneumothorax in 18 cases, fluidothorax in 3 cases, CT-guided lung abscess drainage in 2 cases, and CT-guided pneumatocele drainage in 2 cases) were the most common thoracic surgical procedures. Pleurectomy/decortication surgery was done in 10 cases. Additionally, 12 lung parenchyma-sparing resections were performed, while lobectomy was required in 2 cases. Resection of postintubation tracheal stenosis due to a severe course of COVID-19 pneumonia was indicated in 2 patients. CONCLUSION: Even mild COVID-19 may cause a considerable morphological a functional alteration of the respiratory system. The most common complications of COVID-19 pneumonia that require a thoracic surgical intervention include pathologies associated with an air leak and accumulation of air (pneumothorax, pneumomediastinum and subcutaneous emphysema). The development of pulmonary necrosis, symptomatic bronchiectasis, pneumatocele, and bullous-fibrotic formations may result in pneumothorax, hemothorax or thoracic empyema in sporadic cases. An early thoracic surgical intervention to treat thoracic complications of COVID-19 pneumonia can improve the survival of COVID-19 patients.

[Nephroblastoma -  30-years period of its treatment in the University Hospital Motol, Prague]. / Nefroblastom -  30 let lécby ve Fakultní nemocnici v Motole.

INTRODUCTION: Nephroblastoma (Wilms tumor - WT) is the most common solid tumor of kidney in children. We present treatment development of WT at the Department of Pediatric Hematology and Oncology, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol (KDHO) in the Czech Republic over 30 years. Patients that were treated prior to access to the International Society of Pediatric Oncology (SIOP) protocols are considered to be the historical group, then we have patients treated according to SIOP 9, SIOP 93-01 and SIOP 2001 protocols as full participants of SIOP studies. PATIENTS AND METHODS: Between January 1980 and April 2009, we treated 330 patients with WT at KDHO: 91 patients in historical group (1980-1988), 94 pts in SIOP 9 (1988-1993), 80 pts in SIOP 93-01 (1994-2001) and 65 pts in SIOP 2001 (2002-2009). Overall survival (OS) and event-free survival (EFS) were analyzed by Kaplan-Meier test. RESULTS: The overall ten-year EFS was 81.2% and OS 87.6%. Fifty-eight patients from the 330 (17.6%) had metastases at diagnosis, EFS without metastatic process was 84.6% compared to 65.4% with metastasis presented at diagnosis (p = 0.0003), OS was 70.7% compared to 91.2% (p < 0.0001). One hundred and seventy patients (51.5%) were treated with preoperative chemotherapy and/or radiotherapy, whereas 158 patients (47.5%) underwent primary nephrectomy; EFS and OS did not differ: neoadjuvant vs primary nephrectomy EFS was 81.2% vs 80.9% (p = 0.85), OS 89.4% vs 85.4% (p = 0.38). Sixty (18%) patients experienced disease recurrence; OS after relapse was 33%. In the historical group, EFS and OS were 85.7% and 91.2%. In patients treated according to the SIOP 9 protocol, EFS and OS were 68.1% and 74.5%, resp. In patients treated according to SIOP 93-01, it was 83.6% and 93.7%, resp. and in patients treated according to 87 SIOP 2001, it was 7% and 95.4% (p = 0.001 and p = 0.0008), resp. CONCLUSION: WT is a well treatable disease. The aim for the future is to maintain the current very good survival while minimizing the treatment intensity.

Diagnostic dilemmas of infantile sarcoma of the forearm.

The authors present an interesting case of a suckling baby treated for forearm tumour. All the preoperative examinations including the imaging methods are documented, as are the surgical procedures and the final results. The case report is interesting not only because such surgery is infrequent but also due to the unpredictable progress of the final diagnosis statement. Before surgery the tumour was diagnosed as an organising haematoma; based on clinical and radiological signs the diagnosis subsequently rose to rapidly growing haemangioma or vascular malformation causing arm paresis and vascular supply disorder. The diagnosis was changed to angiolipoma during surgery. The final histopathological statement was: infantile fibrosarcoma. Despite the virtue of imaging methods and meticulous clinical examination, the surgical and histopathological findings are not necessarily absolutely identical. Having presented this particular case the authors would like to share their experience.

[Treatment results in patients treated from 1980 to 2004 for Wilms' tumour in a single centre]. / Lécebné výsledky pacientu lécených v letech 1980-2004 na jediném pracovisti pro nefroblastom.

BACKGROUNDS: The principle behind the treatment of nephroblastoma has been similar for at least 4 decades, based on vincristine and dactinomycine, radiotherapy in selected stages. The last three decades have been characterised by the aim to reduce the intensity and length of treatment. DESIGN: To retrospectively compare survival rates and treatment success in a cohort of patients aged under 19 years, treated from 1980 to 2004 at a single centre by five consecutive treatment protocols. MATERIALS AND METHODS: The outcome was evaluated in patients treated consecutively by two protocols established at the centre before 1980 and modified in 1986, and from 1988 consecutively by three accepted protocols, SIOP9, SIOP93 and SIOP2001. RESULTS: Overall survival as well as event-free survival rates were evaluated by Kaplan-Meier functions in 315 patients (52.7% women). The average age at diagnosis was 3.9 +/- 2.9 years, median 3.3, range 0.01-17.2 years. Age over 12 years in 2.2% patients. The average follow-up time was 13.1 +/- 7.8, median 13.6, range 0.2-27.8 years. The original 104 weeks of protocol KDO86 treatment had a 10-year overall survival rate of 91.9 +/- 3.2%. Overall survival significantly fell with radiotherapy reduction in lower clinical stages and treatment diversification in protocols with substantial treatment length reduction. Overall survival returned to the original value of KDO86 only in 1994, when SIOP93 was accepted with a 10-year overall survival rate of 92.47 +/- 3.0% and event-free survival 85%, with similar trends in the latest protocol, SIOP2001. In the entire cohort two coincident malignancies (tumour duplicities) were found: one B-lymphoma, one neuroblastoma. A second malignancy occurred in one patient--superficial spreading melanoma. CONCLUSION: from the retrospective view the accepted SIOP9 protocol has a significantly worse outcome in both the overall survival and in event-free survival rate compared with the original therapy. Only the SIOP93 and SIOP2001 protocols accepted after 2003 have an acceptable 10-year overall survival rate (around 92%) as well as event-free survival (85%) with substantially reduced length and intensity of treatment, lowering the risk of late effects.

[Late effect of treatment of nephroblastoma in patients treated in 1980-2001 in a single centre]. / Pozdní následky Wilmsova tumoru a jeho lécby u pacientu lécených v letech 1980-2001 na jediném pracovisti.

BACKGROUNDS: The aim of the study was to describe the late effects in a cohort of patients in long-term remission (> 5 years from end of treatment) diagnosed and treated for nephroblastoma at the single paediatric centre during 1980- 2001. PATIENTS AND METHODS: 151 patients were examined for renal function, lipid profile, sonography, echocardiography, exercise capacity and postural status. Age at diagnosis was 3.7 +/- 2.7 years, median 3.1, range 0.01-17.2 years. The cohort included 55% of women. Age in the study 19.4 +/- 5.8, median 19.6 years, range 7.8-36 years. Anthracyclines (ATC) were administered to 25.9% of the cohort. Abdominal radiotherapy (RTA) was required in 34.2%. RESULTS: Creatinine clearance was on average 1.56 +/- 0.56 ml/s/1.73m2, (median 1.49 ml/s/1.73m2). Proteinuria was 0.18 +/- 0.30 g/24 h/m2, median 0.13 mg/24 h/m2. Three patients had proteinuria above 1 g/24 h with a normal glomerular filtration rate and s-albumin. Hypertension was treated in 8.6% of patients (6% by pharmacotherapy). Increased diastolic blood pressure (DBP) and systolic blood pressure (SBP) was found in adolescents: DBP > 90 Torr was found in 10.2% of patients and SBP > 135 Torr in 8.3%, all of them above the age of 15 years. ECHO did not reveal any pathology even in patients treated by ATC. Plasma cholesterol, LDL, HDL, triglycerides were outside the recommended range in two or more parameters in 28.9% of the cohort. Lipoprotein Lp(a) > 500 mg.l(-1) (more than 200% higher than the upper limit) was found in 15.2%. Low peak oxygen consumption (VO2peak) was found in 40% of the cohort. Scoliosis (Sc) was anamnestically found in 46%. Prevalence of Sc according to the age of treatment has a similar trend as the reduced use of the RTA. Pulmonary function test showed a moderate increase in the functional residual capacity (the average Z-score of 1.35). VO2 peak correlates positively with the inspiratory capacity (p < 0.05). CONCLUSION: Based on the found pathologies and known risks, a schedule of late effect prevention and monitoring of patients in long-term NFB remission was established. It should include clinical examination, kidney function and blood pressure monitoring, sonographic and echocardiography examination, long-term physiotherapeutic care and prevention of cardiovascular diseases.

[Radical surgery and intensive chemotherapy are necessary for successful treatment of osteosarcoma]. / Radikální operacní výkon a intenzivní chemoterapie jsou podmínkou úspesné lécby osteosarkomu.

BACKGROUND: We evaluated the therapeutic results in 44 patients (17 girls and 27 boys) with osteosarcoma from 1997 to 2006.Their average age was 12.8 years (2.5-20.2). 41 patients had localised disease and 3 had primary metastases. PATIENTS AND METHODS: We treated our 44 patients using CCG 7921 POG 9351 INT 0133, the therapeutic protocol of the North American cooperative Children's Oncology Group.The median of the follow up was 5.5 years (2-11 years). RESULTS: 40 patients went into complete remission. 19 patients suffered relapses. Of these, 17 patients died - 15 progressed, 1 died due to treatment-related toxicity, 1 died due to secondary acute myeloid leukaemia. As a whole, the patients had a 5-year overall survival rate (OS) of 58.4% and a 5-year event free survival rate (EFS) of 46.7%. The patients with localised extremity osteosarcoma (n = 40) had a 5-year EFS rate of 51%. The patients with good histological response (n = 22) had a 5-year EFS rate of 63.6%, while patients with poor histological response (n = 18) achieved a 5-year EFS rate of 30.5% (p = 0.009). CONCLUSION: The results of treatment of patients with localised extremity osteosarcoma and patients with good histological response to preoperative treatment were very good. The prognosis of patients with axial localisation and metastatic involvement was poor.

[Clinical relevance of chromosomal aberrations in bone and soft tissue tumors in children and young adults]. / Klinický význam chromozomálních zmen u nádoru kostí a mekkých tkání detí a mladistvých.

BACKGROUND: We present the results of a cytogenetic and molecular cytogenetic analysis of a series of patients with bone and soft tissue tumors. PATIENTS ANDMETHODS: We analyzed a cohort of 26 patients with Ewing sarcoma/PNET, 15 patients with rhabdomyosarcoma, 5 with synovial sarcoma and one patient with an undifferentiated sarcoma using the cytogenetic and molecular cytogenetic techniques M-FISH and arrayCGH. RESULTS: We found nonrandom chromosomal structural and numerical changes with diagnostic and prognostic relevance in most patients. Eight patients with ES/PNET had only a t(11;22)(q24;q12), eight patients had secondary aberrations as well and six had only secondary aberrations. In the RMS patients we detected the t(1;13)(p36;q14) once and the t(2;13)(q35;q14) four times, both of them characteristic for the alveolar subtype with poor prognosis and numerical aberrations, characteristic for the embryonal subtype, in five patients. Four patients with synovial sarcoma had the diagnostic t(X;18)(p11.2;q11.2), one of them had a complex karyotype with a complex t(X;18;21) (p11.2;q11.2;q11.2) together with t(2;5)(q24-32;p13-14) and t(12;20)(p11;q13). We correlated the karyotype of cancer cells with histopathologic morphologic analysis, clinical outcome and foreign published results. CONCLUSION: Cytogenetic and molecular cytogenetic analysis is a valuable diagnostic tool in bone and soft tissue tumors, especially in less differentiated subtypes, and as such it should be an integral part of curative care.

[Tumors in children with birth defects. Current data from the Czech Republic]. / Nádorová onemocnení u detí narozených s vrozenou vadou aktuální data v Ceské republice.

AIM OF STUDY: An analysis of birth defects incidences in a co-incidence with children age tumors in the Czech Republic in 1994 - 2005. Some bio-social factors (maternal age, birth weight, gestational week at birth) and their roles were studied as well. TYPE OF STUDY: Retrospective demografic-epidemiological analysis of birth defects and children age tumors incidences in children born in the Czech Republic during 1994 - 2005. MATERIAL AND METHODS: Data from the National Birth Defects Register and National Oncological Register (both run in the Institute for Health Information and Statistics) in the Czech Republic were used along with some additional data from the Register of newborns and Register of mothers at childbirth. Out of these data, a group of children with both birth defect and tumor was analyzed according to particular diagnoses and to some selected bio-social factors. Out of the total number 1707 children with tumor (934 (54.7%) boys and 773 (45.3%) girls) were 1572 children without birth defect and 135 with both tumor and birth defect. Total number of children with birth defect were 39 197 (39 059 live births and 138 stillbirths), 22 741 (58.1%) boys and 16 435 (41.9%) girls (in 21 cases the sex was not specified). In these children totally 53 539 birth defect diagnoses were registered (30 739 in boys, 22 781 in girls and 19 in children with unspecified sex). RESULTS: In 1572 children without birth defect and with tumor, a mean age at time of tumor diagnosis was 3.6 years, in 135 children with both tumor and birth defect was 2.2 years, which is significantly lower (p < 0.001, Mann-Whitney U test). No statistically significant difference was found in birthweight and birthlenght and gestational week and maternal age at time of delivery. An increased frequency of tumors in the group of children with birth defect was found in groups mesothelial tumors (C45 - C49), tumors of urinary tract (C64 - C68) and tumors of head and neck (C00 - C14, C30 - C31). On the other hand, a decreased tumor frequency in the group of children with birth defect was found in groups of lymfoid and haematopoietic tumors ((C81 - C96) and tumors of eye and brain (C69 - C72). As a risk factor of tumorigenesis in in children with birth defect was a birth defect from groups of defects of cardiovascular system, uropoietic system, chromosal aberrations and other unspecified defects. In children with both birth defect and tumor a decreased survival rate (p = 0.0437, Log-rank test) was found. A decreased survival rate was also confirmed after tumor diagnosis, although this decrease was not statistically significant (p = 0.2021, Log-rank test). There is also a highly statistically significant difference (p < 0.001, Log-rank test) in survival between groups with and without a birth defect prior to tumor diagnosis. CONCLUSIONS: A higher risk of tumorigenesis in children with birth defect (compared to children without birth defect) was confirmed. There was also a lower survival in a group of children with tumor and birth defect compared to those with tumor and without birth defects. A higher risk of tumorigenesis in some types of birt defects was also found.

[Use of ruthenuim 106 in retinoblastoma treatment]. / Vyuzití Ru106 pro lécbu retinoblastomu.

The Charles University Teaching Hospital in Prague - Motol started to treat patients with retinoblastoma by means of brachytherapy after obtaining the permission to use closed source of ionizing radiation in the beginning of the year 2003. The applicator containing ruthenium (106Ru) emitting mostly the beta radiation was chosen. Half-life is 369 days and the nominal activity of the source is 21.1 MBq. The applicator is placed in place for one to several days according to the prominence of the tumor and actual activity of the source. Duration of the application is calculated with a special program. In the year 2003, three patients with retinoblastoma were treated. In one case bilateral involvement was determined, and the brachytherapy was used for treatment of both eyes. The next patient was treated twice; one treatment followed the other with different localization of the applicator because of too large basis of the tumor. In 2003, altogether the brachytherapy was used for treatment of retinoblastoma five times. In all cases, the combined treatment (chemoreduction, teletherapy, transpupillary thermotherapy, or cryotherapy) was performed. One eyeball was enucleated because of severe post-radiation retinopathy, the second one for persisting tractional retinal detachment. In remaining cases no serious complications or progression of the malignancy were observed.

[Radical surgery in the complex treatment of hepatoblastoma]. / Chirurgická radikalita v komplexní lécbe hepatoblastomu.

BACKGROUND: Evaluation of treatment results in children with hepatoblastoma--a retrospective study of clinical and pathological data of surgically treated children. METHODS AND RESULTS: At the clinic of authors, 28 children were operated for hepatoblastoma during 1991 to 2002. Average age of patients was 2.2 years. When tumors were classified according to PRETEX system, 3 children were in the stadium I, 12 children in stadium II, 12 children in stadium III, and one child in the stadium IV. At the diagnosis, lung metastases were found in 3 children. Till 1996 the treatment was initiated by a primary operation, since 1996 by a preoperative chemotherapy. Chemotherapy was administered according to the SIOP protocols. Primary operation was done in 13 children, 15 children were operated after the pre-operation chemotherapy. Liver resection included right-sided lobectomy in 7 cases, extended right-sided lobectomy in 4 cases, left-sided lobectomy in 8 cases, right-sided trisegmentectomy in 5 cases, left-sided trisegmentectomy in 3 cases. In our studied group the three years of event free survival was achieved in 75%, overall survival in 86%. Four children died, two of them because of the progression of the disease, two for the complication during the therapy. CONCLUSIONS: Combination of the radical surgical resection with preoperative and postoperative chemotherapy enables successful treatment of the childhood hepatoblastoma.

[Optimal combined therapy in retinoblastoma]. / Optimalizace kombinované lécby retinoblastomu.

Eighteen patients suffering of retinoblastoma during three years period (1999-2001) were treated in two departments of ophthalmology in the Czech Republic. In four cases, the involvement was bilateral. In six eyes, because of very late stage of the disease at the time of diagnosis, the initial treatment was the enucleation. The rest, (sixteen eyes) was treated by chemoreduction (chemotherapy) and different combinations of local therapeutic methods according to their respective findings. Nine eyes from this cohort were enucleated in different period of time after the beginning of the treatment because of the relapse of the disease, its continuing or complications of the treatment. In the remaining seven eyes there are no sings of tumor activity. The fractioned radiotherapy was used in the treatment in one eye only and this eye was enucleated subsequently. So the maintaining therapy was successful in seven eyes of sixteen involved, or in 43.75% of cases.

[Cerebrospinal fluid cytology in retinoblastoma--possibility of early detection of tumor dissemination into the CNS]. / Cytologie mozkomísního moku u retinoblastomu--moznost vcasného záchytu diseminace nádoru do CNS.

Retinoblastoma is a malignant tumourous which occurs in childhood. The most important factors which influence possible cure of patients with a retinoblastoma are early detection of the disease, correct diagnosis and adequate therapy. In the submitted case-record the authors provide evidence of the importance of cytological examination of cerebrospinal fluid which is important in retinoblastoma in particular for the follow-up of treatment. Cytological examination of cerebrospinal fluid in this type of tumour is very reliable and can reveal infiltration of tumour cells into the CNS much sooner than imaging methods.

[High-dose chemotherapy in the treatment of children with malignant lymphoma]. / Vysokodávkovaná chemoterapie v lécbe detí s maligním lymfomem.

BACKGROUND: Children with primary refractory or recurrent malignant lymphoma have usually poor prognosis. Less than 10% of those, who were treated with conventional-dose regimens had survived for 2 years. In an attempt to improve the outcome for these patients, we explored the role of consolidation high-dose chemotherapy with autografting. METHODS AND RESULTS: Forty-five patients with poor-prognosis lymphoma, of whom 27 were males, underwent megatherapy between January 1992 and December 1999. High-dose chemotherapy was indicated in patients with poor initial response to first-line chemotherapy (14 cases) or in the relapse (31 cases). The group consisted of 27 patients with Hodgkin's disease and 18 patients with non-Hodgkin's lymphoma. The median age was 14.7 years. The conditioning for Hodgkin's disease patients contained cyclophosphamide, etoposide and busulfan or carmustine. Patients with non-Hodgkin's lymphomas received cyclophosphamide, etoposide and busulfan or total body irradiation. Bone marrow was used as the source of haemopoietic stem cells in ten patients, peripheral blood in twenty-eight, and both sources were used in seven patients. After the median follow-up of 47 months, the final survival was 61%. Eleven patients died of the disease progression, four of the infectious complications, one at a car accident. Median time to relapse after the transplantation was 7.5 months. CONCLUSIONS: Further improvement of these results will require earlier transplantation, improved preparative regiments or early posttransplant immunotherapy.

Endemic incidence of infections caused by Mycobacterium kansasii in the Karviná district in 1968-1995 (analysis of epidemiological data--review).

The Karviná district (northwestern part of North Moravia and Silesia) is typical by its industrial character, above all mining of black coal which is coked and which led to the devastation of the countryside. The ratio of light industry is low. In a small area (347 km2) there is a population of 824 inhabitants per km2. The population is concentrated in particular in urban agglomerations of the flat block type. Up to 1990 almost 55% of the population was employed in heavy industry. Due to its industrial activities, incl. metallurgical plants and ironworks in nearby Ostrava and Trinec, the district is one of the areas with a heavily contaminated atmosphere in particular with solid aerosol containing toxic metals (the values of solid aerosol varied on average between 100 and 150 micrograms/ml), the elevated values of Nox due to contamination from traffic and polyaromatic hydrocarbons were not negligible either during the investigation period. Since 1968 an endemic incidence of mycobacteria has been recorded which is due to Mycobacterium kansasii. At first only an occasional incidence was involved, since 1973 there has been a more substantial increase with a maximum in 1983 (64 cases) and thus up to 1995 there are 961 cases on records, incl. 787 (81.8%) in men and 174 (18.2%) in women. From the total number of recorded M. kansasii in 937 instances (97.3%) the lungs were affected (777 men, 160 women). The mean annual incidence was 34.3 cases, i.e. 12.03 per 100,000 population (28.1, i.e. 20/100,000 in men, 6.2, i.e. 4.28/100,000 in women). As to age, 78.8% of cases are recorded in the age bracket from 25 to 64 years (in men 81%, in women 68.9%). The highest specific morbidity in men is in the age group from 45-54 years (on average 73.13 per 100,000 per year), in women in the age group from 75 to 84 years (on average 9.75 per 100,000 per year). As to occupation, the ratio of mine employees at the time of contraction of the disease (incl. retired miners) was 52.2%), other workers 14.6%--all stigmatized by an increased dust concentration in other workplaces in heavy industry. As far as the domicile is concerned, the incidence was by far highest in Havírov (more than 56%), followed by Karviná (26.7%). These towns are inhabited mostly by miners. As to the mode of assessment 68.8% cases were diagnosed on account of pulmonary complaints and during dispensarization (stigmatization by dust) and 24.6% cases during preventive radiodiagnostic examinations of miners lungs. It did not prove possible to reveal the source. Interhuman transmission was not proved in any of the patients. The causal agent of the infection is most probably transmitted through water (by the aerogenic route). M. kansasii was isolated from drinking water (560 samples, in 7% M. kansasii was found), as well as in industrial water. In 1971-1995 a total of 1231 samples of industrial water were examined (scrapings and untreated water). From these M. kansasii was isolated in 43.7% (538 specimens). In soil samples (93) and small mouse-like rodents (187) M. kansasii was not detected. The authors confirm that the development of disease depends in a decisive way on the susceptibility of the individual which in turn depends in particular on exposure to dust with possible lung damage and contamination of the atmosphere. In the district there is a high incidence of recurring acute diseases of the airways in children, incl. allergies affecting the airways. In the towns of Karviná, Havírov, Orlová, Bohumín and Ceský Tesín there is a high ratio of children with reduced immunity. In November 1981 to January 1982 987 first form pupils were examined for postvaccination TB allergy (standard tuberculin and avian tuberculin were used). The reactivity to avian tuberculin was higher than to standard tuberculin (see results). The highest ratio of intense reactions (30%) was recorded in children from Havírov where there is also the highest specific (and simple) incidence in adults.

[Osteosarcoma - Clinical, Radiological and Histologic Evaluation of Preoperative Chemotherapy in Correlation with Long-term Survival.]. / Osteosarkom - klinické, radiologické a histologické hodnocení úcinku predoperacní chemoterapie ve vztahu k dlouhodobému prezívání nemocných.

This paper evaluates the clinical, radiological and histomorphologic effect of neoadjuvant chemotherapy in 37 patients with II B osteosarcomas. The results are compared according to the type of surgery, local recurrence and lung metastasis at a minimal follow up of five years in patients who underwent surgery at the orthopedic clinic in Prague Bulovka in 1982 - 1992. All patients continued with adjuvant chemotherapy after surgery. Bad clinical response (increase of circumference, decrease in range of motion and increase of pain) correlated with the bad histologic response evaluated according to the COSS criteria. Accurate evaluation of a complete radiological documentation (tumor calcification on plain radiographs and CT scans, decrease of tumor volume on plain radiographs and CT scans or MRI and the disappearance of pathologic vascularisation) can quite precisely estimate a good response to preoperative chemotherapy and indicate limb sparing surgery. The radiological evaluation, especially of an incomplete record, does not always fully correlate with the histomorphologic response. Good prognosis for long term survival was observed in patients with a more then 80% tumor cell necrosis. CT scans or MRI performed immediately before the beginning and at the end of preoperative chemotherapy are necessary for a reliable evaluation of tumor calcification and intramedullar tumor spread. The persistence or disappearance of pathologic vascularisation seems to be the most significant marker to evaluate residual vital tumor cells. A good radiological response enables a safe indication for a limb sparing procedure as an alternative to amputation. The radiological evaluation must be correlated with different histomorphologic osteosarcoma subtypes as well as with possible changes, especially in vascularisation, due to an incorrect biopsy or pathologic fracture. Key words: osteosarcoma, neoadjuvant chemotherapy, long term survival, indication for limb salvage.

Bone metastasizing renal tumor of childhood. A clinicopathological study of eleven cases from the Prague Pediatric Tumor Registry.

Eleven patients with bone metastasizing renal tumor of childhood (BMRTCh) who were diagnosed and treated in our departments over a 20-year period were reviewed. The incidence among all malignant renal tumors in children up to 15 years of age in our files was 3.7%. The male to female ratio was 10:1. The morphology had a uniform, predominantly clear cell finely vascularized pattern in all of them. Various previously recognized variations of the classic pattern such as hyalinization, nuclear palisading and cyst formation were observed in some patients. Electron microscopy showed that coarse vacuolization of the tumor seen at the light microscopic level was due to distended extracellular spaces surrounded by tumor cells and their cytoplasmic processes. Immunohistochemistry of the tumor cells revealed positive vimentin in all cases, and focally positive muscle specific actin in one. A prominent feature was fascicles of perivascular spindle cells. They were considered to be tumor cells rather than stromal elements since their morphology was close to the appearance of the polygonal tumor cells. The follow up data were available for ten patients. Four developed bone metastases, three of them died of the disease progression. Another patient died of lymph node dissemination and gastrointestinal bleeding. Six patients survived for a period of 29 months to 14 years following the diagnosis.

[The solitary kidney in patients after nephrectomy in Wilm's tumor]. / Solitární ledvina u pacientu po nefrektomii pro Wilmsuv nádor.

A single kidney in patients with agenesis or after nephrectomy is regarded as a risk factor. Primarily, the role of glomerular hyperfiltration and later possible glomerular sclerosis are emphasised. Complex treatment of Wilms tumour patients includes previous chemotherapy and radiotherapy. The aim of our study was to investigate late sequelae of this aggressive treatment on the morphology and function of a single kidney and to compare these results with a group of single kidney patients, where the diagnosis of Wilms tumour was excluded.

[Flow cytometry in primary renal tumors in childhood]. / Prutoková cytometrie primárních nádoru ledvin v detském veku.

A group of nineteen primary renal tumors in childhood was analyzed by flow-cytometry. All clinically important entities were included. Paraffin embedded material was used. Two anaplastic nephroblastomas and a case of renal rhabdomyosarcoma had an aneuploid DNA content. One Wilm's tumor showed a moderate DNA-hyperdiploidy. One of two rhabdoid tumors showed a marked right-sided shift of G1/G0 phase from that of a control and was considered as probably hyperdiploid. All other tumors including high grade neoplasms such as rhabdoid tumor and bone metastasizing tumors were found in the DNA-diploid range. Proliferation index was high in most tumors and in six it reached or exceeded 40. Mitotic index counted in the histological sections correlated with the percentage of G2 + M phase in most cases. Although small, the group of tumors under study shows that prognostic criteria cannot be based on the DNA content or on the proliferation index only. The only relevant result may be an overt DNA-aneuploidy in anaplastic nephroblastomas. Difficulties in interpreting the results of flow cytometry are discussed.