Agreement among and within groups of pathologists in the classification of rhabdomyosarcoma and related childhood sarcomas. Report of an international study of four pathology classifications

BACKGROUND

An International Pathology study was conducted to measure the agreement demonstrated among and within groups of pathologists involved in the categorization of childhood rhabdomyosarcoma according to four pathology classifications. Data concerning agreement and survival experience according to patho-new subtypes were used as a basis for selection of a proposed new pathologic classification.

METHODS

A random sample of 800 eligible patients was chosen from the Intergroup Rhabdomyosarcoma Study II (IRS-II) and was reviewed by pathologists representing eight institutions. A 20% sample of the 800 patients was then reviewed by the pathologists to determine the level of agreement with their original classification. In each instance the patients were classified according to four pathology systems: the conventional system, the International Society for Pediatric Oncology system (SIOP), the National Cancer Institute (NCI) system, and the cytohistologic system.

RESULTS

Among the groups of pathologists, the highest measure of agreement was a Kappa value of K = 0.451 for the conventional system, followed by K = 0.406 for the SIOP system, K = 0.384 for the NCI system, and K = 0.328 for the cytohistologic system. For reproducibility within the groups of pathologists, the highest measure of agreement was K = 0.605 for the conventional system, followed by K = 0.579 for the NCI system, K = 0.573 for the SIOP system, and K = 0.508 for the cytohistologic system.

CONCLUSIONS

There was a general similarity between the agreement reached within the modified conventional, STOP, and NCI systems, with the modified conventional system having the highest Kappa values, and thus the highest measure of agreement, both among and within the groups of pathologists. Also, the subtypes of the conventional system demonstrated a highly significant relationship to survival time. Hence, based on criteria of reproducibilty and prognostic significance, the proposed classification will essentially be a modification of the conventional system with elements of the SIOP and NCI systems.

[Neonatal hyperthyroidism in non-diagnosed Basedow's disease of the mother. Problems of diagnosis and therapy illustrated by a case history]

A male preterm infant (born at 34 weeks, birth weight 2130 g) developed jaundice (total bilirubin 7.4 mg/dl), hepatosplenomegaly, thrombocytopenia (82,000/microliters) and a raised C-reactive protein (1.2 mg/dl). Although sepsis was suspected, no organism was demonstrated. When the mother visited the child for the first time after 2 weeks, she had florid hyperthyroidism. This explained many of the child's clinical features (poor weight gain, tachycardia, exophthalmos). Both mother and child had raised TSH receptor antibodies (mother: 684.6 U/l; 54.1 U/l, normal < 15 U/l), an increased free T4 and a suppressed TSH. Because of the tachycardia, the child was treated with propranolol (1 mg/kg.d for 5 weeks). He was also initially given Lugol's solution (25 mg iodide/kg.d for 1 week) and then propylthiouracil (7 mg/kg.d) because of the increasing total T3. L-Thyroxine replacement was subsequently required for a period of 2.5 weeks because of treatment-related hypothyroidism. Since stopping treatment (at 12 weeks of age), the child has developed normally.--Neonatal hyperthyroidism due to transplacental transfer of TSH receptor antibodies associated with maternal Graves' disease is a rare self-limiting condition. However, it may pose considerable danger to the child both in utero and postnatally (with a mortality if untreated of up to 20%). Interdisciplinary cooperation is essential.

[Multiple cerebral infarcts with resulting multicystic encephalomalacia in a premature infant with Enterobacter sakazakii meningitis]

Enterobacter sakazakii is an uncommon cause of neonatal meningitis. The prognosis of newborns with meningitis due to Enterobacter sakazakii is poor, the fatality rate is reported as high as 50%. Survivors usually have severe neurologic complications. Most computed tomography (CT) findings were low density lesions of white matter and cortex suggesting infarctions which underwent cystic degeneration. We present one premature baby with meningitis due to Enterobacter sakazakii and large bilateral regions of hypo- and hyperdensity suggesting massive hemorrhagic and nonhemorrhagic intracerebral infarctions leading to multiple cystic encephalomalacia.

[Plexiform fibrohistiocytic tumor. Histology, immunohistology and ultrastructure]

An example of a plexiform fibrohistiocytic tumour (PFT) is presented for the first time in the German-language literature. The diagnostic criteria for this rare soft-tissue neoplasm of childhood and young adulthood, which is mostly subcutaneous in location and has a tendency to recur, include the plexiform structure which gives it its name, extensive siderin deposits and numerous osteoclast-like giant cells. The development of the tumour described here, which occurred in the field of radiation of a malignant haemangiopericytoma excised 7 years previously, indicates the possibility of induction of PFT by radiation.

Clinico-pathological criteria with prognostic relevance in hepatoblastoma

We investigated clinical data and histological specimens of 46 patients with a hepatoblastoma (HB) for prognostic criteria. Disease-free survival (DFS) of 23 patients treated in the German Cooperative Study HB-89 (1988-1990) was 83%, in contrast to 40% in 10 children with other chemotherapy regimes (1977-1987) and 38% in 13 with only a tumour resection (P = 0.005). Tumour residence after resection (R category) correlated significantly with probability of DFS (P = 0.0001). This was also the case for pT status, according to the pTNM classification for liver carcinoma (P = 0.0007), involvement of one or both liver lobes (P = 0.004), multiplicity of tumour nodes (P = 0.001), vascular invasion (P = 0.0006) and expression of nucleolar organiser regions as an indicator for proliferation activity of tumour cells (P = 0.05). Patients' age and histopathological subtypes could only indicate outcome, while tumour size and serum alpha-fetoprotein values were not significantly related to prognosis. In multivariate analysis, pT status and R categories remained significant. These should be applied in all cooperative trials on HB.

Intraabdominal desmoplastic small-cell tumor with divergent differentiation: clinicopathological findings and DNA ploidy

Five cases of intraabdominal small-cell tumor with divergent differentiation are reported. All patients were of male sex. They were 10, 15, 20, 21, and 30 years of age at time of diagnosis, respectively. By light microscopy, the tumors consisted of small cells arranged in groups, nests, and clusters separated by a collagen-rich desmoplastic stroma. Immunohistochemical studies revealed the coexpression of mesenchymal, epithelial, and neural markers. Notably, all tumors coexpressed vimentin, cytokeratin, and desmin, the latter in a remarkable paranuclear dot-like fashion. In contrast to other authors, we did not find chromogranin. DNA image cytometry on four cases demonstrated two diploid and two aneuploid (hyperdiploid) cases. No correlation was found between ploidy and prognosis. One patient died from disease, another died from veno-occlusive disease after bone marrow transplantation, and the remaining patients are alive, but have progressive intraabdominal disease. Thus, our findings support the poor prognosis in this type of tumor.

Treatment of malignant testicular tumors in childhood: results of the German National Study 1982-1992

The German Cooperative Protocol for treatment of testicular germ cell tumors in childhood registered 106 patients from January 1982 through February 1992. Sixty-one patients suffered from yolk sac tumors (YST); 25 patients from differentiated teratomas (TD); 19 patients from malignant teratomas of either intermediate (MTI), undifferentiated (MTU), or trophoblastic type (MTT), and 1 patient from a seminoma. A stratified chemotherapy based on stage and histology was administered in addition to unilateral orchiectomy: Standard chemotherapy consisted of four treatments with vinblastine, bleomycin, and cisplatinum. If viable tumor was suspected after two treatments with standard chemotherapy, a delayed explorative laparotomy was done. There were two options based on the histological findings: In case of complete tumor regression, the standard chemotherapy was continued. In case of incomplete tumor response, patients received a salvage chemotherapy consisting of three treatments with VP 16 (etoposide), ifosfamide, and cisplatinum. In addition three injections with VP 16 were given as a maintenance therapy. The following results were obtained: YST: 59 patients with stage I. Forty-nine patients were followed according to "wait and see" policy. Eight of these needed a delayed standard chemotherapy. The relapse free survival of all 61 patients in 100%. Median observation time is 49 months. TD: Twenty-five patients had stage I. No chemotherapy was given. The relapse free survival is 100%. Median observation time is 48 months. Malignant teratomas (MTI, MTU, MTT): 8 patients had stage I. Three of these received adjuvant chemotherapy and 5 lymphadenectomy without chemotherapy. All patients survived without relapse. Nine patients had stage II and received standard chemotherapy. Four of these patients had a delayed explorative laparotomy leading to a salvage therapy in two patients. All patients survived relapse free. Two patients had stage III. Of these 1 received standard chemotherapy and is well. One patient suffering from MTU stage IIIA died due to candida septicemia during salvage therapy. Median observation time of the entire group is 60 months.

DNA analysis in hepatoblastoma by flow and image cytometry

BACKGROUND

In several types of tumors, including hepatocellular carcinoma, prognosis could be correlated with DNA ploidy. Few studies have been performed on hepatoblastoma with contradictory results.

METHODS

Twenty-nine cases of nonpretreated hepatoblastoma were studied with flow cytometry and image cytometry for DNA index and proliferation index using paraffin-embedded tissue.

RESULTS

Twenty-three (79.9%) tumors were diploid, and 6 (20.7%) were aneuploid (hyperdiploid). Patients with diploid tumors were younger than those with aneuploid tumors. With regard to stage, diploid tumors were almost equally distributed among stages (tumor, lymph node metastases, distant metastases), whereas aneuploid tumors tended to occur in higher stages (tumor, lymph node metastases, distant metastases). Diploid tumors had clearly a better prognosis than aneuploid tumors, although the difference was not statistically significant (flow cytometry, P = 0.06; image cytometry, P = 0.16). A more favorable prognosis was also noted for hepatoblastomas with low-proliferation index (< or = 7%), but the difference from tumors with high-proliferation index (> 7%) again was not statistically significant (P = 0.16).

CONCLUSIONS

Although no statistically significant differences in prognosis between hepatoblastomas with diploid and aneuploid DNA content, respectively, were found, there is a clear tendency that diploid hepatoblastomas behave more favorably. The same is true for hepatoblastomas with low-proliferation index.

Macrophage production of basic fibroblast growth factor in the fibroproliferative disorder of alveolar fibrosis after lung injury

In organ repair following injury, macrophages accumulate and granulation tissue, comprised of fibroblasts and endothelial cells, develops in the injured area. Basic fibroblast growth factor (bFGF), a potent stimulator of fibroblast and endothelial cell growth, has been linked to the fibroproliferative process. Macrophages are thought to play a central role in the fibroproliferative response, and prior studies indicate that they produce bFGF. Whereas it is plausible that macrophages produce bFGF in a fibroproliferative process, currently no data exists that directly identifies the macrophage as a source of bFGF in a fibroproliferative disorder. We used the model of acute intraalveolar granulation tissue formation following lung injury to determine if the macrophage was a cellular source of bFGF in a naturally occurring fibroproliferative process. To examine this hypothesis, patients with severe acute lung injury underwent bronchoalveolar lavage during the phase of lung repair. Polymerase chain reaction and Northern analysis of macrophage RNA revealed the presence of two species of bFGF messenger RNA (4.4 kb and 1.9 kb). Metabolic labeling studies of recovered macrophages revealed a newly synthesized 18-kd protein with antigenic similarity to bFGF. Immunohistochemical evaluation of lung tissue from patients who died following acute lung injury, showed numerous bFGF immunoreactive macrophages present within airspaces containing fibroblastic and vascular tissue proliferation. This investigation has identified the alveolar macrophage as a cellular source of bFGF in the fibroproliferative disorder of intraalveolar fibrosis following acute lung injury.

Mutation of the p53 gene in neuroblastoma and its relationship with N-myc amplification

Mutation of the p53 tumor suppressor gene frequently occurs in a variety of tumors including lung, breast, gastrointestinal, and brain, as well as lymphomas-leukemias. Neuroblastoma, one of the most common solid tumors in childhood, often has amplification of the N-myc gene. We examined for mutations of the p53 tumor suppressor gene by single-strand conformational polymorphism using polymerase chain reaction products and direct sequencing method in neuroblastoma; in addition, we assessed the relationship between p53 mutation and N-myc gene amplification in the disease. Of 86 DNA samples from patients with neuroblastoma, two mutations (2%) were found in the coding region of the p53 gene. Each mutation caused a substitution of amino acid residues. One mutation was located in exon 5, and another was in exon 6. N-myc gene was amplified in 26% of the samples. No p53 mutations were found in neuroblastoma samples with N-myc amplification. In the two individuals, p53 mutations appeared as their disease became more progressive. The neurofibromatosis 1 (NF1) gene is frequently abnormal in another neural disorder, neurofibromatosis type 1; in addition, a potential mutational hot spot of NF1 at lysine at codon 1423 has been identified in several types of tumors. Using single-strand conformational polymorphism, we were unable to detect an abnormality in this region of NF1 in 50 samples of neuroblastoma. The data suggest that p53 mutations occasionally are associated with progression of neuroblastomas, and tumorigenetic influences of mutant p53 may differ from those of N-myc.

Discrimination between immunoaccessory and phagocytic monocytes/macrophages of the skin in paraffin-embedded tissue by the monoclonal antibody Ki-M1P

The variety of functions performed by monocytes and macrophages is reflected in their phenotypic diversity. Investigation of this complex system is facilitated by Ki-M1P, a new monoclonal antibody which recognizes a differentiation antigen on monocytes/macrophages in paraffin-embedded tissues. To test its usefulness as a pan-macrophage marker in the skin, we immunohistochemically analysed paraffin-embedded biopsy material from seven healthy individuals and 190 patients with a variety of dermatoses. Immunoreactivity was compared with results obtained with the antibodies KP-1, MAC-387, UCHL-1 and S-100. In normal skin, epidermal Langerhans cells were Ki-M1P-. Strong expression of this marker was detected on spindle-shaped as well as dendritic perivascular and intervascular macrophages. Pathological reaction forms such as giant cells and epithelioid cells in granulomatous dermatoses were also Ki-M1P+. The high specificity of Ki-M1P is reflected in the lack of reactivity with tumour cells in non-monocytic neoplasms and Langerhans cell histiocytosis. Thus, Ki-M1P is a useful marker for skin macrophages, discriminating between the immunoaccessory and the phagocytic compartments.

[Improved prognosis of intracranial germ cell tumors by intensified therapy: results of the MAKEI 89 therapy protocol]

Germ cell tumors of the central nervous system are histological identical to the extracranial tumor sites. According to the localisation germ cell tumors of the CNS are different in symptoms, diagnostic approaches, kind and location of metastases and stratification of therapy. Since 1986 patients with intracranial germ cell tumors are registered in the ongoing study for non-testicular germ cell tumors (MAKEI) of the German Society of Pediatric Oncology and Hematology, and are treated in accordance to therapy guidelines for extracranial sites. In MAKEI 89 therapy strategy was revised with a reduction of radiotherapy and an increased cumulative cisplatinum dose from 200 mg/m2 to 400 mg/m2. Patients with germinoma receive after histologic diagnosis radiotherapy consisting of 30 Gy craniospinal irradiation and 15 Gy tumorboost. Malignant non-germinoma receive after diagnosis by tumor marker in CSF and/or serum 2 courses bleomycin 15 mg/m2 day 1-3, Etoposide 150 mg/m2 day 1 + 2 and cisplatinum 20 mg/m2 days 4-8 (BEP), continued by 2 courses Vinblastine 3 mg/m2 day 1 + 2, Ifosfamide 1500 mg/m2 days 1-5 and cisplatinum 20 mg/m2 days 1-5 (VIP), followed by 30 Gy craniospinal irradiation and 20 Gy tumor boost. In teratoma first line therapy is complete resection. In incomplete resected cases adjuvant chemotherapy according to histological grading is administered. Until 31st January, 1993 101 patients (pts) were registered, containing 69 protocol pts. Diagnosis in protocol pts was teratoma in 8 cases, 2 pts died postnatal because of extended disease, 2/8 pts relapsed, but were salvaged by chemotherapy. 40 pts offered germinomas.(ABSTRACT TRUNCATED AT 250 WORDS)

[Therapy of testicular germ cell tumors. Current status of the MAHO studies]

The GPOH-MAHO trials designed in 3/82 and 7/88 for treatment of childhood testicular germ cell tumors registered 3/92 105 pts. In MAHO 82 study 57 pts. and in MAHO 88 study 48 pts. were treated. Histologically 60% of the tumors revealed yolk sac tumors (YST), 22% teratomas (TD) and 18% malignant teratomas (MTI, MTU, MTT). Beside unilateral orchiectomy, according to stage and histology a stratified chemotherapy was administered. Standard chemotherapy consisted of 4 courses VLB, BLM, DDP, after 2 courses standard chemotherapy if vital tumor was suspected: explorative laparatomy. According to laparatomy some patients received salvage chemotherapy of 3 courses VP 16, IFO and DDP. The following results were obtained: YST: 59 pts. with stage I. Of these 10 received adjuvant chemotherapy with VLB, BML, DDP. 49 pts. were followed according to wait and see policy and not treated by adjuvant chemotherapy; 8 pts. had a relapse. 5 were treated with standard chemotherapy and 1 pt. with salvage therapy. 1 pt. had stage II and another stage III. Both received standard chemotherapy. The survival of all 61 pts. is 100%. Median observation time is 4 years. TD: 25 pts. had stage I. No chemotherapy was given. The relapse free survival is 100%. Median observation time is 4 years. Malignant teratomas (MTI, MTU, MTT): 8 pts. had stage I. Of these 3 received adjuvant chemotherapy, 5 lymphadenectomy without chemotherapy. All patients survived without relapse. 8 pts. had stage II and received standard chemotherapy, of these 4 pts. had stage IIc and explorative laparotomy was done. According to the result 2 pts. received salvage therapy. All pts. survived relapse free.(ABSTRACT TRUNCATED AT 250 WORDS)

Rhabdomyosarcomas with primary presentation in the skin

Five primary and two metastatic rhabdomyosarcomas (RMS) with primary presentation in the skin were studied by conventional light microscopy and immunohistochemistry. These cases account for only 0.7% of the 682 cases of RMS collected at two large institutions with a main interest in soft tissue tumors. All but one tumor, which was an embryonal RMS, corresponded to the alveolar subtype. The myogenic nature of the tumor cells was supported by the immunophenotype including positive reactions for vimentin, desmin, and muscle actin. Clinical findings included a male predominance, young age of the patients and the location of all primary cutaneous RMS in the face. One of the two metastatic RMS presented at birth with a clinical picture highly suggestive of congenital metastatic neuroblastoma, notably because of a 100-fold amplification of the N-myc copy number. Thus, this case illustrates again that an amplification of the N-myc oncogene is not restricted to neuroblastoma, but may also occur in other tumor types.

Keratin-positive, epithelial membrane antigen-positive solitary pelvic tumor with ultrastructural features of large cell lymphoma

A case of an unusual malignant solitary pelvic tumor is presented. The neoplastic cells were positive for keratin and epithelial membrane antigen. Although ultrastructural features (prominent nuclear pleomorphism, abundant polyribosomes, and absence of cell junctions) were those typically seen in large cell lymphomas, lymphoid markers were not detected, and immunoglobulin heavy-chain gene and T-cell receptor beta-chain gene rearrangements were not identified. Combination chemotherapy resulted in complete remission.

Mesoblastic nephroma metastatic to the lungs and heart--another face of this peculiar lesion: case report and review of the literature

A case of mesoblastic nephroma in a 14-month-old girl who developed consecutive metastases in the lung and the heart is presented. This tumor is considered to be benign and cured by surgery only. Recurrent cases are extremely rare and usually related to unclear surgical margins. Metastatic mesoblastic nephroma has been previously described in only two cases. The present case highlights a new, previously undescribed feature--the ability to metastasize to sites other than lung.

Spindle cell variants of embryonal rhabdomyosarcoma in the paratesticular region. A report of the Intergroup Rhabdomyosarcoma Study

We reviewed 173 cases of paratesticular rhabdomyosarcoma (RMS) of Intergroup Rhabdomyosarcoma Studies (IRS)-I, -II, and -III for evaluation of possible histological factors that might account for the good prognosis of these patients. Almost all cases (161 of 173 cases, 93.1%) occurring in this site were of embryonal histology. A spindle-cell subtype of embryonal RMS was identified that presented a storiform growth pattern with abundant collagen between the tumor cells in most cases. Other tumors of this subtype showed an arrangement of tumor cells in bundles with a low to moderate amount of collagen, resembling a leiomyosarcoma. The other embryonal RMS in this site had the classical embryonal cytology. The spindle-cell subtype was highly differentiated by immunohistochemistry and electron microscopy. Lymph node metastasis was found in seven of 43 patients (16.3%) with a RMS of spindle-cell subtype, compared with 40 of 112 patients (35.7%) with RMS of non-spindle-cell type. Clinical data from patients with spindle-cell subtypes of the paratesticular lesions revealed that they almost always had an association with clinical groups of limited disease (32 patients, 74.4%, with Group I; 10 patients, 23.3%, with Group II disease) and a significantly better prognosis (95.5% survival at 5 years) when compared with patients with the classic embryonal variant of RMS (80% survival at 5 years, p < 0.035). The incidence and anatomic distribution of this spindle cell subtype of embryonal RMS was estimated on 800 randomly selected patients from IRS-II. It was found in the head and neck, extremities, orbit, and some other sites, but 30.6% were located in the paratesticular area. Patients with spindle cell RMS of nonparatesticular sites usually had more extensive disease compared with patients having paratesticular lesions; two thirds of the cases had gross residual tumor after surgery or metastatic tumor at diagnosis. We conclude that spindle-cell RMS is a subtype of embryonal RMS with a very favorable prognosis. The site factor of the paratesticular localization may allow earlier diagnosis of the spindle-cell lesions compared with other sites. Other unknown factors may also play a role.

Rare tumors in childhood: pathological aspects. Experience of the Kiel Pediatric Tumor Registry

A wide variety of rare tumors can occur in childhood and adolescence. Tumors can be rare in any age group; common tumors of adults can appear in childhood and adolescence, and many rare tumors and tumor-like lesions show a predilection for younger age groups. Comparatively frequent tumors can present with rare histologic features or can occur in rare atypical locations, and, finally, seemingly common but, in fact, rare tumors have to be distinguished from truly common but rarely recognized tumors. Thus, the spectrum of rare tumors is broad, reflecting the fluent reality of life.

Infectious risks of Broviac catheters in children with neoplastic diseases: a matched pairs analysis

In the present study the complication rate of Broviac catheters in the therapy of children with cancer was determined. Of special interest was the question of to what extent the incidence of bacteremias is increased by the implant. For this reason the method of matched pairs analysis was chosen comparing 55 patients with 61 catheters to 1 child each who received the therapy via peripheral veins. Apart from having the same disease, the same therapy protocol and the same age group the partners had a similar number of leukocytopenic days (leukocyte counts, < 1000/microliters) in the study period. The observation time was 9671 days in the catheter group and 9666 days in the control group. During this time 167 fever episodes (17.7 episodes/1000 days) were recorded in the patients with implant but only 133 episodes (14.0/1000 days) in the control patients. Study and control groups had similar frequencies of fever of unknown origin with leukocyte counts > or = 1000/microliters and fever with a known focus. However, 29 bacteremias (2.9 episodes/1000 days) represented a 4 times higher complication rate with the use of Broviac catheters than in the control group (7 bacteremias, 0.7 episode/1000 days). Episodes of fever of unknown origin with leukocytopenia were 1.5 times more common in the catheter group than in the control group. Although it is not possible to prove that the catheter played a role as focus of bacterial infection, an increased risk of infection must be supposed. The Broviac catheter meets with broad approval by the patients, parents and medical staff.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experiences with surfactant therapy of adult respiratory distress syndrome]

We report on 2 patients with ARDS, who underwent a therapy with surfactant. In both cases the underlying reason for the lung disease probably was a viral pneumonia. In both patients the gas exchange improved after tracheal instillation of surfactant. This improvement however was much less than we know it from therapy of the respiratory distress syndrome of the premature babies. Reasons for these differences in response to surfactant are discussed.

[Preoperative chemotherapy of nephroblastoma. Preliminary results of the SIOP-9/GPO therapy study]

The therapeutic strategy of the SIOP-9 study includes pre-operative chemotherapy for all patients with nephroblastoma diagnosed by imaging methods aged between 0.5 and 16 years. By pre-operative chemotherapy the rate of radical resectable tumors should be increased and thereby the intensity of postoperative therapy, in particular of radiotherapy, diminished. Patients with nephroblastoma stage I-III were in case of tumorresponse randomised in either a 4 weeks or 8 weeks arm of pre-operative treatment with ACT D and VCR. The question was, if a prolongation of pre-operative chemotherapy could increase the relative part of stage I. Between 1/1/89 and 6/30/91 from 49 oncologic centres of former western Germany 188 patients were registered in the SIOP-9/GPO. From the stage I-III patients between 0.5 and 16 years 80.1% were pretreated with cytostatic agents. Only 53.9% of the patients with tumorresponse were randomised. The relative frequency of intraoperative ruptures was with 3% lower in the group of pretreated patients than in the primary operated (15.3%). The stage distribution for all Wilms' tumor patients showed a prevalence of stage I with 43.3% (after pre-operative treatment 59%; after primary operation 28%). Abdominal radiotherapy was performed in 22.4%. The event-free survival rate of all nephroblastoma lay at 85% 3 years after diagnosis (stage I standard 96%; unfavorable histology all stages 45%). 7.3% of the patients developed a hepatopathy under treatment and 7.8% even a VOD according to the criteria of McDonald.(ABSTRACT TRUNCATED AT 250 WORDS)

Spindle cell rhabdomyosarcoma. A prognostically favorable variant of rhabdomyosarcoma

Twenty-one cases of embryonal rhabdomyosarcoma, composed mainly of elongated spindle cells arranged in a fasciculated or storiform pattern, were retrieved from the files of the German-Italian Cooperative Soft Tissue Sarcoma Study. The term spindle cell rhabdomyosarcoma is proposed to designate this histotype. Spindle cell rhabdomyosarcoma predilected male patients (18 males, three females) and involved mostly the paratesticular area (12 cases) and the head and neck region (six cases). Histologically, all cases were characterized by a uniform proliferation of elongated spindle cells with eosinophilic and fibrillar cytoplasm mimicking smooth muscle fibers; immunocytochemical studies disclosed high expression of the muscle markers titin, desmin, and myoglobin. Clinical information was available in 17 cases; according to the Intergroup Rhabdomyosarcoma Study (IRS) grouping system, 13 were classified in group I, two in group II, and two in group III. Sixteen patients were well and alive 24 to 100 months after diagnosis; one patient died from disease progression 24 months after diagnosis. Analysis of our results determined that spindle cell rhabdomyosarcoma constitutes a rare variant of the embryonal form, showing a high degree of skeletal muscle differentiation and a low malignant potential; it should therefore be distinguished from classical forms of embryonal rhabdomyosarcoma.

Malignant renal tumors of childhood

The prognosis in nephroblastoma (Wilms' tumor) has been improved considerably by treatment protocols combining surgery, chemotherapy, radiation therapy, and, in some clinical trials, pre-operative chemotherapy. Cure is now achieved in most patients. All clinical trials have employed treatment strategies tailored to the individual risk of the patient, including the histological subtype of the tumor. In the National Wilms' Tumor Study (NWTS) of the United States these subtypes have been divided into two groups of tumors according to their "favorable" or "unfavorable" histology. At the Kiel Pediatric Tumor Registry we have devised a system which distinguishes three groups of tumors classified according to prognosis. The first group includes tumors with a favorable prognosis, even if only surgery is performed. These comprise congenital mesoblastic nephroma (CMN) and cystic, partially differentiated nephroblastoma (CPDN). The second group consists of tumors posing an intermediate risk, such as typical nephroblastoma and its histological variants characterized by variations in the relative proportions of the histological components. Fetal rhabdomyomatous nephroblastoma (FRN) is also included in this group. The third group comprises tumors of high risk such as anaplastic nephroblastoma, clear cell sarcoma of the kidney (CCSK), and malignant rhabdoid tumor of the kidney (MRTK). Since histological diagnosis plays a crucial role in the assignment of a patient to a particular type of treatment protocol, knowledge of the histological appearance of the various tumor types both with and without preoperative treatment is of utmost importance.