Adsorption Behavior of N(2), Water, C(6) Hydrocarbons, and Bulkier Benzene Derivative (TMB) on Na-X Zeolite and Its K(+)-, Rb(+)-, and Cs(+)-Exchanged Analogues

The hydrothermal crystallization of X-type zeolite with a Si/Al ratio of 1.15 was achieved from the Na(2)O-Al(2)O(3)-SiO(2)-H(2)O system at 368 K under static conditions. The post-synthesis modification was carried out by a conventional ion-exchange technique to obtain K(+)-, Rb(+)-, and Cs(+)-exchanged samples with different degrees of exchange. All the samples were characterized using chemical analysis, IR, SEM, powder XRD, low-temperature nitrogen adsorption, and equilibrium sorption uptakes of different probe molecules. The relative intensities of the XRD peaks of cation-exchanged zeolite were found to be affected to different extents, depending on the nature and the concentration of nonframework cationic size, without any shift in the positions of reflection. The sorptive properties of the K-, Rb-, and Cs-exchanged samples were studied using nitrogen, water, and different C(6) hydrocarbons including bulkier benzene derivative 1,3,5-trimethylbenzene (TMB) as probe molecules. The trend observed in chemical potential estimated as a function of nitrogen coverage indicates different sorption selectivity because of differences in the cationic size and population. Sorption uptake kinetics for probe molecules such as water, n-hexane, cyclohexane, benzene, and TMB were also studied. The samples with higher degrees of exchange and/or cationic size have shown a decrease in hydrophilic character due to the formation of irregular networks of water molecules connected with preadsorbed water molecules, framework oxygen ions, and nonframework cations. Among C(6) hydrocarbons including TMB, the benzene molecule is found to be the most promising probe for the estimation of openness of structure and surface heterogeneity as well. Copyright 2001 Academic Press.

Clear cell sarcoma of the pediatric kidney: detailed description and analysis of variant histologic patterns of a tumor with many faces

Clear cell sarcoma of the kidney is the most frequently misdiagnosed renal tumor in children. The majority of tumors present the classic histologic pattern, which allows a definitive diagnosis. However, there are unusual cases with lack of "clear" appearance of tumor cells, predominance or exclusive presence of variant histologic patterns, and presence of "neoplastic" appearing entrapped tubules. Furthermore, a small biopsy specimen may not show the classic histologic pattern. These tumors present a diagnostic challenge for the practicing pathologist who should be aware of the deviations from the classic histologic features in order to make a correct diagnosis.

Primary PNET of kidney: report of two cases and review of literature

PNET of the kidney is a rare tumor with only a few published reports. In view of poorer prognosis and different therapeutic approach, renal PNET should therefore be differentiated from other primary renal neoplasma such as Wilms tumor, renal neuroblastoma and malignant rhabdoid tumor which on histology resemble renal PNET. Two cases of renal PNET have been described in this report. Cut surface of the tumor in both cases was greyish white lobulated, with multiple tiny cystic areas. Histologically, tumor consisted of loosely cohesive sheets of small to medium sized monomorphic cells with round nuclei and little cytoplasm. Tumor cells showed diffuse strong membrane positivity for MIC2 and focal weak to moderate positivity for NSE and vimentin. Renal PNET should therefore be included in differential diagnosis of rapidly enlarging renal lumps presenting with local infiltration and aggressive behaviour, particularly in children and young adults. Diffuse strong membrane positivity for MIC2 in PNET is helpful in differentiating it from other primary renal neoplasms.

Natural history and biology of stage A neuroblastoma: a Pediatric Oncology Group Study

PURPOSE

To prospectively analyze the outcome of patients with Stage A neuroblastoma (NB) treated with surgery alone, especially with regard to the prognostic significance of age, tumor site, MYCN copy number, tumor cell ploidy, and histology.

PATIENTS AND METHODS

The clinical course of 329 patients with Stage A disease registered on the POG NB Biology Study #9047 between February, 1990 and October, 1997 were evaluated. Age, tumor site, MYCN copy number, tumor cell ploidy, and histology were analyzed for their impact on event-free survival (EFS) and survival (S).

RESULTS

The 5-year estimated EFS and S rates for the 329 patients were 91% (+/-3%) and 96% (+/-2%), respectively. The EFS rate was similar for infants younger than 12 months and children age 12 months or older, but age older than 12 months was predictive of lower S rates (P = 0.044). Patients with adrenal, abdominal non-adrenal, thoracic, and cervical tumors had similar S rates. The majority of patients had tumors with favorable biologic features, and only 3% had MYCN amplification. For infants with diploid tumors, the EFS rate was 82% (+/-16%), but effective therapy yielded an S rate of 100%. Rate of S was 80% (+/-26%) and 64% (+/-27%) for patients with unfavorable tumor histology and MYCN-amplified tumors, respectively.

CONCLUSION

The outcome for patients with Stage A NB treated with surgery alone is excellent. Although EFS and S rates were significantly worse for patients with MYCN-amplified tumors, a subset achieved long-term remission after surgery alone. For patients with Stage A and MYCN amplification, additional factors are needed to distinguish the patients who will achieve long-term remission with surgery alone from those who will develop recurrent disease.

Castleman's disease of the left triceps in a child suspected to be a small round cell tumor of childhood

Castleman's disease (CD) is histologically characterized by a proliferation of polyclonal small lymphocytes and plasma cells. The clinical presentation varies widely, but most commonly manifests as a solitary mediastinal mass, incidentally found on radiographic examination. We present a case of a 10-year-old girl who exhibited a left arm mass which, preoperatively and on frozen section, was diagnosed as a small round cell tumor of childhood (SRCT). This report emphasizes the unusual location of CD in the soft tissue and as a rare entity to be considered in the differential diagnosis of SRCT.

Molecular and virologic characteristics of lymphoid malignancies in children with AIDS

PURPOSE

To characterize AIDS-associated lymphoid malignancies in children.

PATIENTS AND METHODS

We studied lymphomas and B-cell leukemias from 25 children with AIDS for immunoglobulin heavy chain gene clonality, c-myc oncogene abnormalities, and presence of HIV and Epstein-Barr virus.

RESULTS

Monoclonal immunoglobulin gene rearrangements were identified in 22 of 23 cases tested, the single exception being one of mucosa-associated lymphoid tissue. Immunoglobulin gene/c-myc translocations were found in 3 of 4 cases of B (surface immunoglobulin-positive)-acute lymphoblastic leukemia, 8 of 11 small noncleaved cell lymphomas, and 1 of 5 large cell lymphomas. Mutations of c-myc were found in 2 of 13 small noncleaved cell lymphomas, 1 of 2 Epstein-Barr virus-positive mucosa-associated lymphoid tissue neoplasms, and 1 of 4 Epstein-Barr virus-negative B-acute lymphoblastic leukemia. Six small noncleaved cell lymphomas, both mucosa-associated lymphoid tissue neoplasms and one of large cell lymphoma had high levels of Epstein-Barr virus in tumor tissue. Hodgkin's disease tissue and B-acute lymphoblastic leukemia tumors were negative for EBV. Proviral HIV-1 was not detected in any tumor.

CONCLUSIONS

AIDS-associated lymphoid malignancies in children appear to have a different distribution of histologic subtypes than adult HIV-infected individuals, fewer large cell lymphomas occur in children. The small noncleaved cell lymphomas exhibit a lower frequency as well as different locations of c-myc mutations than AIDS-associated small noncleaved cell lymphomas in adults.

The International Neuroblastoma Pathology Classification (the Shimada system)

BACKGROUND

The International Neuroblastoma Pathology Committee, which is comprised of six member pathologists, was convened with the objective of proposing a prognostically significant and biologically relevant classification based on morphologic features of neuroblastic tumors (NTs) (i.e., neuroblastoma, ganglioneuroblastoma, and ganglioneuroma).

METHODS

A total of 227 cases were reviewed. Consensus diagnoses from morphologic features (criteria described separately) based on five of six or six of six agreements by the reviewer pathologists were used for prognostic analysis. Prognostic effects of morphology, both individual and in combination, taken in conjunction with age (Shimada classification, histologic grade, and risk group), were analyzed.

RESULTS

Approximately 99% of cases (224 of 227) had consensus diagnoses for categorization: neuroblastoma (Schwannian stroma-poor), 190 cases; ganglioneuroblastoma, intermixed (Schwannian stroma-rich), 5 cases; ganglioneuroma (Schwannian stroma-dominant) maturing, 1 case; ganglioneuroblastoma, nodular (composite Schwannian stroma-rich/stroma-dominant and stroma-poor), 19 cases; and NT-unclassifiable, 9 cases. For the NTs, subtype (93% consensus: undifferentiated, 6 cases; poorly differentiated, 155 cases; and differentiated, 15 cases), mitosis-karyorrhexis index (90% consensus: low, 94 cases; intermediate, 40 cases; and high, 37 cases), mitotic rate (75% consensus: low, 89 cases; high, 50 cases; and not determined, 4 cases), and calcification (100% consensus: yes, 110 cases and no, 80 cases) were recorded. Statistical analysis demonstrated that the Shimada classification system (90% consensus; 3-year event free survival: 85% for the group with favorable histology and 41% for the group with unfavorable histology; P = 0.31 x 10(-9)) had a significantly stronger prognostic effect than individual features and other combinations.

CONCLUSIONS

The International Neuroblastoma Pathology Classification, a system based on a framework of the Shimada classification with minor modifications, is proposed for international use in assessing NTs.

Terminology and morphologic criteria of neuroblastic tumors: recommendations by the International Neuroblastoma Pathology Committee

BACKGROUND

As part of the international cooperative effort to develop a complete set of International Neuroblastoma Risk Groups, the International Neuroblastoma Pathology Committee (INPC) initiated activities in 1994 to devise a morphologic classification of neuroblastic tumors (NTs; neuroblastoma, ganglioneuroblastoma, and ganglioneuroma).

METHODS

Six member pathologists (H.S., I.M.A., L.P.D., J.H., V.V.J., and B.R.) discussed and defined morphologically based classifications (Shimada classification; risk group and modified risk group proposed by Joshi et al.) on the basis of a review of 227 cases, using various pathologic characteristics of the NTs. The classification-grading system was evaluated for prognostic significance and biologic relevance.

RESULTS

The INPC has adopted a prognostic system modeled on one proposed by Shimada et al. It is an age-linked classification dependent on the differentiation grade of the neuroblasts, their cellular turnover index, and the presence or absence of Schwannian stromal development. Based on morphologic criteria defined in this article, NTs were classified into four categories and their subtypes: 1) neuroblastoma (Schwannian stroma-poor), undifferentiated, poorly differentiated, and differentiating; 2) ganglioneuroblastoma, intermixed (Schwannian stroma-rich); 3) ganglioneuroma (Schwannian stroma-dominant), maturing and mature; and 4) ganglioneuroblastoma, nodular (composite Schwannian stroma-richlstroma-dominant and stroma-poor). Specific features, such as the mitosis-karyorrhexis index, the mitotic rate, and calcification, were also included to allow the prognostic significance of the classification to be tested. Recommendations are made regarding the surgical materials to use for an optimal pathobiologic assessment and the practical handling of samples.

CONCLUSIONS

The current article covers the essentials and important points regarding the histopathologic evaluation of NTs. Using the morphologic criteria described herein, the INPC is proposing the International Neuroblastoma Pathology Classification. It is reported in a companion article in this issue (Cancer 1999;86:363-71).

Prognostic significance of age, MYCN oncogene amplification, tumor cell ploidy, and histology in 110 infants with stage D(S) neuroblastoma: the pediatric oncology group experience--a pediatric oncology group study

PURPOSE

Although a high rate of spontaneous regression is observed in infants with stage D(S) neuroblastoma (NB), survival is not uniform. To determine the prognostic relevance of age at diagnosis, therapy, and tumor biology in infants with stage D(S) NB, we reviewed the Pediatric Oncology Group (POG) experience.

PATIENTS AND METHODS

A review of patients diagnosed with stage D(S) NB registered on POG protocols was performed. Survival according to age at diagnosis, treatment, and tumor biology was determined.

RESULTS

Between 1987 and 1996, 110 infants with stage D(S) NB had an estimated 3-year survival rate of 85% +/- 4%; survival rate was 71% +/- 8% for infants 2 months of age or younger, and 68% +/- 12%, 44% +/- 33%, and 33% +/- 19% for patients with diploid, MYCN-amplified, and unfavorable histology tumors, respectively. Survival rates were similar for patients who received adjuvant chemotherapy versus those who did not (82% +/- 5% v 93% +/- 6%, respectively; P = .187). Furthermore, there was no statistical difference in survival rate for patients who underwent complete resection of their primary tumor compared with those who underwent partial resection or biopsy only (90% +/- 5% v 78% +/- 7%, respectively; P = .083).

CONCLUSION

Our review confirmed that the survival of infants with stage D(S) NB is excellent. However, subsets of patients with poor prognosis can be identified by young age and unfavorable biologic factors. More effective therapy is needed for the group of stage D(S) infants who show unfavorable clinical and biologic features.

The risk of nephrectomy during local control in abdominal neuroblastoma

METHODS

Eight hundred sixty-eight children presenting from 1981 to 1991 were treated on five multiagent chemotherapy protocols by members of the Pediatric Oncology Group for advanced-stage neuroblastoma with large primary tumors crossing the midline or distant metastasis. Of these children, 696 had abdominal (adrenal or paravertebral) primary tumors. One hundred sixteen children underwent greater than 50% surgical resection of these abdominal primary tumors before chemotherapy, and 233 underwent similar surgery after induction chemotherapy.

RESULTS

Among the 349 who underwent surgical resection, 52 children (14.9%) had nephrectomy or renal infarction during surgery for local control. There was a 25% incidence among those with initial resection (29 patients) and a 9.9% incidence in the postchemotherapy resections (23 patients). Reasons for nephrectomy given by the surgeons included direct involvement of the kidney by adjacent tumor (17 children), clinical impression that the tumor was a Wilms' tumor (11 children), renal vessels could not be separated from the tumor (10 children), extensive tumor surrounding the kidney (8 children), postoperative renal infarction (4 children), marked decrease in unilateral renal function after chemotherapy (1 child), and position of the tumor posterior to the kidney and vena cava making resection without nephrectomy impossible (1 child). Of the patients undergoing nephrectomy, four children had an upper pole nephrectomy in conjunction with their adrenalectomy and resection of the tumor. Pathological review of the resected tumor available in 47 cases demonstrated direct involvement of the renal parenchyma in 18 cases (38% of the nephrectomies) and in 5.2% of those undergoing resection. In children undergoing initial resection, the risk for nephrectomy (as calculated by the methods described by Gart) was more than twice compared with those undergoing resection after chemotherapy (P = .012; odds ratio, 2.32; 95% confidence interval of 1.23 to 4.42).

CONCLUSIONS

This review confirms that renal parenchymal involvement does occur in a significant number of children with abdominal neuroblastoma. It also suggests that preoperative chemotherapy may decrease the number of nephrectomies required to achieve a total or subtotal resection.

Benign and malignant smooth muscle tumors containing Epstein-Barr virus in children with AIDS

Smooth muscle tumors (leiomyosarcomas) are the second most prevalent malignancy of children with the acquired immunodeficiency syndrome (AIDS). We have investigated the tumors, plasma, and peripheral white blood cells of eight children with AIDS with smooth muscle tumors for evidence of tumor association with human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV). Very low levels of HIV were found in the tumors of the AIDS patients, probably resulting from blood-borne carriage of virus. These smooth muscle tumors had very high quantities of EBV in all the tumor cells by in situ hybridization, with an average of 4.5 EBV genomes per cell by quantitative polymerase chain reaction amplification. Increased amounts of EBV were found in the peripheral blood cells of two AIDS patients before the time of tumor diagnosis. EBV clonality studies demonstrated different monoclonal EBV infection of two separate colonic tumors from one patient, and dual or mixed monoclonal EBV infection in another patient. The muscle cells of leiomyomas and leiomyosarcomas of patients with AIDS demonstrated prominent staining with antibodies to the EBV receptor. The uniform distribution and striking amount of EBV in the tumor cells demonstrates that EBV is capable of infecting smooth muscle cells and that these cells support EBV replication. Clonal EBV proliferation suggests that EBV infection occurs at an early stage of tumor development. These findings indicate that EBV has a causal role in the oncogenesis of leiomyosarcomas of patients with AIDS.

Correlation between morphologic and nonmorphologic prognostic markers of neuroblastoma

Morphologic (Shimada classification--SC, original and modified histologic grades--OHG and MHG) and nonmorphologic (serum LDH, 1 p del, DNA index, N-myc copy number, telomerase activity, and expression of MRP, MDR1, and TRK) prognostic markers for NB have been reviewed. The functional role of these nonmorphologic markers in the development and progression of this disease include abnormal cell proliferation, resistance to chemotherapeutic agents, and induction of apoptosis. A statistically significant association between high OHG/MHG (grade 3), DNA index of 1 (diploidy), > 1 copy of N-myc per haploid genome and serum LDH of > or = 1500 IU/1 (p < 0.001 for each) has been described. In SC, undifferentiated histology and high MKI are associated with N-myc amplification. However, a lack of correlation between morphology and N-myc amplification has been found in localized NB. Confirmation of these observations must now be obtained on larger numbers of prospectively studied cases. Data on correlation for various prognostic markers could provide guidelines for identification of subsets of NB having strongly significant, readily determinable, reproducible, and relatively inexpensive prognostic markers that could ultimately be used to design an algorithm for risk-specific therapy.

The spectrum of mucosa-associated lymphoid tissue lesions in pediatric patients infected with HIV: A clinicopathologic study of six cases

Mucosa-associated lymphoid tissue (MALT) lesions in nonimmunocompromised individuals include reactive lymphoid proliferations and both low- and high-grade lymphoid neoplasms. These lesions occur at extranodal mucosal sites, such as the gastrointestinal tract, bronchus, salivary gland, and other locations. The spectrum of MALT lesions in children with HIV infection had not been previously described. In this study, six cases that demonstrated the spectrum of MALT lesions in pediatric patients, aged 28 months to 23 years, who had HIV infection were described. Half the patients acquired the infection perinatally, and half acquired it by transfusion. Mucosal sites of involvement included the salivary gland (4 patients), bronchiolar mucosa (2 patients), and oropharyngeal mucosa (1 patient). One patient had lesions in lung and oropharynx sequentially; all others had involvement of solitary sites. The histologic diagnoses included myoepithelial sialadenitis (MESA), MESA with low-grade MALT lymphoma, typical low-grade MALT lymphoma, diffuse large cell lymphoma (DLCL), and atypical pulmonary lymphoid hyperplasia and lymphoid interstitial pneumonitis complex. The two cases of high-grade DLCL were confined to mucosal sites (tonsil and parotid); in one of these patients, a previous biopsy specimen showed a MALT lesion with low-grade features. In two cases, quantitation of the Epstein-Barr virus (EBV) genome by the polymerase chain reaction showed a very high copy number in peripheral blood mononuclear cells but a low copy number in the MALT lesion, which suggested that MALT lesions may not be directly associated with EBV infection. Two patients who had high-grade tumors (DLCL) were successfully treated with chemotherapy and radiation therapy. The remaining patients, all of whom had low-grade MALT lesions, received either corticosteroids or alpha-interferon or no specific therapy; in all patients, the lesions followed an indolent clinical course. Clinicians and pathologists should be alert to the possibility that MALT lesions, including MALT lymphomas, may be present in children who have AIDS.

Crohn's disease of the prepuce in a 12-year-old boy: a case report and review of the literature

We report a case of Crohn's disease with involvement of the foreskin in a 12-year-old boy. One year previously, on the basis of clinical features (diarrhea with blood, perianal fissures) and histologic examination, a diagnosis of Crohn's disease was made. Subsequently, he developed phimosis and balanitis and underwent circumcision. Sections submitted from the foreskin revealed noncaseating granulomatous inflammation consistent with Crohn's disease. Crohn's disease with involvement of the genitalia is unusual. Only 26 cases including our case have been reported in the scientific literature. We have analyzed these cases with emphasis on gender, age, clinical features, duration of Crohn's disease, and probable mode of spread to the genitalia. Careful examination of sections from genital lesions, including those submitted from the foreskin, is essential to detect small isolated granulomas that may then lead to the diagnosis of inflammatory bowel disease.

Chemotherapy for patients with recurrent or refractory neuroblastoma: a POG Phase II study

PURPOSE

The purpose of this study was to evaluate the efficacy and toxicity of three different salvage regimens (Rx) in children with recurrent or refractory neuroblastoma.

PATIENTS AND METHODS

Forty-six children with recurrent or refractory neuroblastoma received treatment according to one of three regimens: Rx 1 (five patients), high-dose cisplatin (HDP) (200 mg/m2) with concurrent sodium thiosulfate (STS) (9.9 g/m2) as a nephroprotectant and etoposide (VP-16) (200 mg/m2/day for 3 days); Rx 2 (22 patients), high-dose carboplatin (HD-CBDCA) (500 mg/m2/day for 2 days) and VP-16 (100 mg/m2/day for 3 days); Rx 3 (19 patients), ifosfamide (1.5 g/m2/day for 3 days) followed by CBDCA (400 mg/m2) on day 4. Chemotherapy was administered every 3-4 weeks. Responses were assessed following four courses with or without surgery. Patients achieving less than a partial response (PR) on their primary treatment were crossed over to the next regimen (i.e., Rx 1 --> Rx 2 <--> Rx 3).

RESULTS

Rx 1 was ended early owing to grade 4 nephrotoxicity in two patients following their first course. Ten of 22 evaluated patients (45%) primarily (n = 19) or secondarily (n = 3) treated by Rx 2 responded [five complete response (CR) and five PRs]. Nine of the 23 evaluated patients (39%) on Rx 3 as primary (n = 18) or secondary (n = 5) treatment responded (one CR and eight PRs). Grades 3-4 neutropenia and thrombocytopenia occurred after 80% and 50% of courses administered on Rx 2 and Rx 3, respectively. Central venous line infections were the most commonly documented infections on these regimens.

CONCLUSIONS

Rx 2 and Rx 3 are active combinations in patients with recurrent or refractory neuroblastoma and are associated with manageable toxicity. HDP administered as a short i.v. infusion with concurrent STS infusion cannot be safely given to children with neuroblastoma pretreated with cisplatin.

Pathology of acquired immunodeficiency syndrome (AIDS) in children

OVERVIEW

Acquired Immunodeficiency Syndrome (AIDS) was first described to occur in children in 1983. With experience of increasing number of cases of AIDS, pathologic lesions in various organs and tissues such as lungs, brain, G.I. tract, heart, blood vessels, lymph nodes, spleen, bone marrow, etc. became evident in autopsy and biopsy specimens. These pathologic lesions were classified into four groups based on known or suspected pathogenesis: 1) Primary lesions due to Human Immunodeficiency (HIV) infection itself (lymph nodes, brain, etc) 2) associated lesions related to direct or indirect sequelae of HIV infection (Opportunistic infections, PLH/LIP complex, etc) 3) lesions of undetermined pathogenesis, (cardiomyopathy, arteriopathy, thrombocytopenia, nephropathy, etc) 4) lesions of multifactorial pathogenesis (villous atrophy of intestine, thymic lesions, etc).

UPDATE

In recent years the emphasis of pathologic study is on the reactive and neoplastic proliferative disorders. These disorders include nodal and extranodal lymphoproliferative lesions (such as myoepithelial sialadenitis, malignant lymphomas, etc), smooth muscle tumors (SMTs), Kaposi's sarcoma, Human Papilloma virus associated genital lesions and miscellaneous tumors. In a recent study, it has been shown that Epstein-Barr virus (EBV) may be related to the pathogenesis of SMTs. The most recently recognized lymphoproliferative lesions include those of mucosa associated lymphoid tissue (MALT) of salivary glands, lungs and tonsils. The MALT lymphomas in children with AIDS are responsive to therapy and tend to take an indolent clinical course. Therefore recognition of MALT lymphomas as a distinctive lesion in pediatric AIDS is of practical importance. In this view of increasing incidence of HIV and HPV infections in adolescent females seen in certain countries attention should also be focused on early detection of HPV related genital lesions so that their possible progression to intraepithelial and invasive cervical carcinoma can be prevented.

Cancers in children with HIV infection

Malignancies in children with HIV infection have not been as frequent as expected, but they still constitute a fertile area for clinical and basic research. Non-Hodgkin's lymphomas are the most frequent malignancies of children with AIDS and are curable diseases with standard chemotherapy. Leiomyomas and leiomyosarcomas have become the second leading cancer of children with HIV infection and are clearly associated with EBV infection. Treatment for these lesions has not been as successful as that for lymphomas. Other infrequent atypical lymphoproliferative lesions of these patients can often be categorized in the MALT group. Some of these are low-grade lymphomas, whereas others can progress to high grade. The diagnosis of Kaposi's sarcoma in children with AIDS should be carefully reviewed by pathologists experienced with these cases. The diagnosis of KS in children must be made with special care, because some other lesions of HIV-infected children (such as prominent vascularity in lymph nodes) can be confused with KS. Other tumors of these patients are rare and probably are no more frequent than would be expected in the normal population. Because malignancies in children with AIDS are rare, it is important that each one be studied completely with regard to type and incidence, risk factors, and biologic features. To this end, the Pediatric Oncology Group (POG) has established a national registry and treatment protocols. Patient information as well as fresh, frozen, and fixed specimen studies are coordinated through the POG Statistical Office in Gainesville, Florida (telephone, 904-392-5198; FAX, 904-392-8162). The collaborative efforts of all physicians treating children with AIDS and malignancies will be needed to advance our knowledge and efficacy in treating these diseases.

Conventional versus modified morphologic criteria for ganglioneuroblastoma. A review of cases from the Pediatric Oncology Group

BACKGROUND

Conventional criteria for ganglioneuroblastoma (GNB) do not require the presence of ganglioneuromatous component for pathologic diagnosis. This leads to inclusion of a mixed variety of neuroblastic tumors in the category of GNB. Therefore, GNB diagnosed by conventional criteria includes tumors showing more than 5% ganglion cells but no predominant ganglioneuromatous component, as well as tumors containing predominant ganglioneuromatous component. By previously described modified criteria, the former would be considered differentiating neuroblastoma (NB), and only the latter would be considered GNB. Data on Pediatric Oncology Group cases were analyzed to compare the prognostic subgroups of GNB diagnosed by conventional and modified criteria. The two prognostic subgroups (low risk and high risk) were defined on the basis of previously described prognostic differences between histologic grades of differentiating NBs and subtypes of GNB.

METHODS

Pathologic data from cases of neuroblastic tumors registered on Pediatric Oncology Group NB protocols 8104 and 8441 were reviewed. The GNBs diagnosed by conventional and modified criteria were divided into low-risk and high-risk histology subgroups as follows: (1) GNB by conventional criteria: low-risk group, differentiating NB of histologic grades 1 and 2 and GNB of intermixed and borderline subtypes; high-risk group, differentiating NB of histologic grade 3 and GNB of nodular subtype; (2) GNB by modified criteria: low-risk group, GNB of intermixed and borderline subtypes; high-risk group, GNB of nodular subtype.

RESULTS

The low- and high-risk subgroups of GNBs diagnosed by conventional (69 cases) and modified (36 cases) criteria showed statistically significant differences in survival (P = .03 and .01, respectively). However, from the histologic point of view, GNBs diagnosed by modified criteria form a more uniform morphologic group, which can be divided into low- and high-risk subgroups by a single set of morphologic criteria. In contrast, GNBs diagnosed by conventional criteria form a heterogeneous group, which requires two sets of criteria (ie, histologic grade and subtypes of GNB) for its classification into low- and high-risk subgroups.

CONCLUSIONS

The modified criteria for GNB define a morphologically uniform group of neuroblastic tumors to which a single set of prognostic criteria can be applied. It is recommended that the term GNB should be used both clinically and pathologically to designate a distinctive subgroup of neuroblastic tumors, in contrast to the current use, which designates both NB and GNB.

Modified histologic grading of neuroblastomas by replacement of mitotic rate with mitosis karyorrhexis index. A clinicopathologic study of 223 cases from the Pediatric Oncology Group

BACKGROUND

Histologic grading (HG) of neuroblastomas (NB) of prognostic significance is based on the presence of absence of calcification and low mitotic rate ( < or = 10/10 high power fields). Mitosis karyorrhexis Index (MKI) is the main feature used for prognostic categorization in Shimada classification and can be determined more readily than mitotic rate (MR). The purpose of this study is to test whether MKI can be used instead of MR for histologic grading.

METHODS

Low and intermediate MKI were lumped together as low MKI. We replaced MR with the modified MKI categories. Histologic grades for 223 NBs registered with the Pediatric Oncology Group protocols 8104 and 8441, were defined ad follows: HG 1 = calcification + low MKI, HG 2 = calcification or low MKI, HG 3 = high MKI and absence of calcification. Shimada classification was also determined for comparison or modified HGs with favorable histology (FH) and unfavorable histology (UH), HGs were linked with age: low risk (LR) = HG 1 in all age groups + HG 2 in patients age younger than 1 year; high risk (HR) = HG 2 in patients age 1 year of older + HG 3 in all age groups.

RESULTS

Statistically significant differences in 5-year survival were seen in the NBs of different modified HG (1: 92.7%, 2: 74.9%, and 3: 18.2%) and risk groups (LR 93.0% and HR 47.9%) (P < 0.0001 and P = 0.0001, respectively).

CONCLUSIONS

Pathologists may readily adapt to the modified HG described here. Advantages of modified HGs include: (1) familiarity and reproducibility of MKI; (2) no need for linkage with age; and (3) a combination of features used in original HGs and Shimada classification.

Role of immunocytochemistry, electron microscopy, and DNA analysis in fine-needle aspiration biopsy diagnosis of Wilms' tumor

We reviewed the cytologic features and results of ancillary studies in eight fine-needle aspiration biopsies (FNAB) performed by posterior approach in 8 patients with unresectable Wilms' tumor (WT). Chemotherapy was given following the FNAB diagnosis of WT, which was confirmed subsequently by histologic examination of surgically resected specimens. Indications for FNAB included: unresectable tumor, bilateral disease, initial presentation with metastatic disease, uncertainty regarding tumor site, and documentation of recurrence. Cytologic examination revealed blastemal cells (8/8 aspirates), spindle cells (3/8 aspirates), and epithelial differentiation or tubules (3/8 aspirates). There was no cytologic evidence of anaplasia in any of the cases. Immunocytochemical studies on cell blocks and/or smears showed cytokeratin positivity in 5/8 and vimentin positivity in 5/5 of the aspirates in which these studies were performed. Focal positivity for neuron-specific enolase (NSE) was seen in 3/3 aspirates. Stains for actin and leukocyte-common antigen were negative (0/3 and 0/2 aspirates, respectively). DNA ploidy analysis of the aspiration material by flow cytometry revealed near-diploid populations in three aspirates. Electron microscopic findings helpful for diagnosis included: cell junctions, microvilli, flocculent basement membrane-like material, cilia, autophagolysosomes, and lack of neuroectodermal differentiation. Diagnostic morphologic pitfalls for an incorrect diagnosis of neuroblastoma included nuclear molding (all aspirates), pseudorosette formation (one aspirate), and focal NSE positivity (3/3 aspirates). None of the tumors showed anaplasia on histologic examination. Cytologic recognition of the triphasic cellular components of WT (blastemal cells, spindle cells, and epithelial cells) can be helpful for a correct diagnosis; however, in 5/8 aspirates in this study, only the blastemal component was present. In these cases, immunocytochemical stains and electron microscopy proved useful in arriving at a correct FNAB diagnosis of WT. However, NSE positivity can be a pitfall for a diagnosis of neuroblastoma if the radiologic, clinical, and other cytologic features are not clearly delineated. Presence of cytokeratin and vimentin positivity would be helpful in the diagnosis of WT in such instances.

Fine-needle aspiration of chondroblastic osteosarcoma of the skull: report of a case in an 11-year-old girl

We describe an unusual case of chondroblastic osteosarcoma of the skull in an 11-yr-old girl in whom a preoperative diagnosis was made by fine-needle aspiration (FNA) biopsy, followed by histologic confirmation of tissue biopsy and the surgically resected specimen. FNA cytology revealed pleomorphic oval cells with prominent nucleoli along with spindle cells, tumor giant cells, and a chondromyxoid background. The cell block of the aspirated material showed osteoid associated with the malignant cells. Immunocytochemical stains revealed S-100 and vimentin positivity; actin, myoglobin, and cytokeratin stains were negative. Electron microscopy revealed neoplastic cells with chondrocytic differentiation. This case demonstrates the value of FNA biopsy combined with immunocytochemical and ultrastructural studies performed on the aspirated material in diagnosing osteosarcoma from an unusual location such as the base of the skull.

Identification of subsets of neuroblastomas by combined histopathologic and N-myc analysis

BACKGROUND

Neuroblastomas show different histopathologic phenotypes, and the tumor cells can carry normal or multiple copies of the N-myc proto-oncogene (MYCN). Studies of the N-myc gene and histopathology of untreated primary neuroblastomas have demonstrated that both these factors are important in risk assessment.

PURPOSE

Our purpose was to determine if there are any associations between N-myc gene copy number, histopathologic features, clinical stage, and progression-free survival (PFS) and if joint analyses of histopathology and N-myc gene copy number improve risk assessment.

METHODS

The histopathologic phenotype and N-myc gene copy number were determined for 232 biopsy/surgery specimens obtained from untreated primary neuroblastoma patients. Tumors were classified as having favorable or unfavorable histology on the basis of Schwannian stroma (rich versus poor), neuroblastic differentiation (differentiating versus undifferentiated), and mitosis-karyorrhexis (fragmenting nucleus) index (MKI; high, intermediate, or low) in the context of age at diagnosis (Shimada classification). N-myc gene amplification was considered significant when the gene copy number was at least 10-fold higher than normal as determined by Southern blot analysis. Otherwise, tumors were classified as nonamplified for N-myc.

RESULTS

Among 19 stroma-rich tumors, 11 had grossly visible neuroblastic nodules, and two of these had N-myc amplification. Of 213 stroma-poor tumors, 51 had N-myc amplification, all of which were undifferentiated, and 45 (88% of 51) had high MKI. This histologic phenotype was present in less than 10% of tumors with nonamplified N-myc. Of 162 stroma-poor tumors that showed nonamplified N-myc, 45 (28%) were differentiating and 121 (75%) had low MKI. Neuroblastomas of clinical stages I, II, and IV-S nearly always had favorable histology and no amplification of N-myc. Stage III (regional) and particularly stage IV (metastatic) tumors, however, frequently had unfavorable histologic features with or without N-myc amplification. The estimated PFS at the end of 4 years after diagnosis was 83% for patients whose tumors had favorable histology and no N-myc amplification. The estimated PFS for the patients whose neuroblastomas had unfavorable histology, however, was 29% without and 13% with N-myc amplification, respectively. Subsets of patients with stage II, III, or IV disease were identified by both histologic evaluation and N-myc analysis. Multivariate Cox regression analysis indicated that both the histologic and N-myc-based stratifications provided prognostic information that was independent of staging.

CONCLUSIONS

Neuroblastomas with N-myc amplification have a characteristic histopathologic phenotype and an aggressive clinical course. In contrast, neuroblastomas without N-myc amplification exhibit a wide range of histologic features that can define prognostic subsets.

Lack of correlation of N-myc gene amplification with prognosis in localized neuroblastoma: a Pediatric Oncology Group study

Multiple copies of N-myc proto-oncogene are only rarely detected in localized neuroblastomas (NBs), and the prognostic relevance of amplification in this subset of patients is not clear. We analyzed a series of 850 children with NB admitted to a Pediatric Oncology Group NB Biology Study and identified six patients with localized NBs harboring N-myc gene amplification. Three patients whose tumors showed favorable histology by Shimada classification and low-risk histological features according to the Joshi classification have remained disease-free, whereas two of three patients with unfavorable histology tumors have developed recurrent disease. Although earlier studies have indicated that N-myc amplification is associated with diploid DNA content, flow cytometric analysis revealed that only two of the localized tumors contained stem lines with diploid DNA content. Loss of chromosome 1p was not detected by fluorescence in situ hybridization in the two tumors examined. N-myc protein was detected by immunohistochemical studies in four of the five NBs analyzed. However, N-myc protein was not visualized in one of the tumors with stroma-rich histology, and Western blot analysis revealed only low levels of N-myc protein expression in another NB with favorable histology. These studies indicate that the presence of N-myc amplification in localized NBs does not necessarily portend an adverse outcome. Furthermore, the biological features of this subset of N-myc-amplified NBs appear to differ from those of more advanced N-myc-amplified tumors.

Effusion cytology in Burkitt's lymphoma

The American form of Burkitt's lymphoma is a high-grade malignancy which usually involves the abdomen in children and young adults. There is only a limited literature which describes the cytologic features of Burkitt's lymphoma in serous effusions. We present three children with Burkitt's lymphoma initially diagnosed by effusion cytology. The first patient, an 11-yr-old boy, presented with bilateral pleural effusions, ascites, and abdominal masses and had diagnostic pleural fluid cytology without tissue confirmation (ultrastructural examination was performed on the effusion specimen). He died 7 months after the initial diagnosis. The second patient, a 9-yr-old boy, presented with ascites and abdominal masses and had diagnostic peritoneal fluid cytology with a subsequent confirmatory chest wall biopsy. The third patient, a 16-yr-old girl, presented with a 2-month history of irregular menses, a large pelvic mass, lymphadenopathy, and liver masses. Although an ovarian malignancy was clinically suspected, cytologic examination of her peritoneal fluid revealed Burkitt's lymphoma. Surgical exploration revealed involvement of her right ovary, cecum, and terminal ileum. The second and third patients are currently alive with no apparent disease following chemotherapy. In all three patients, effusion cytology revealed Burkitt's lymphoma, characterized by a uniform population of non-cohesive lymphoid cells with noncleaved nuclei, prominent multiple nucleoli, and scanty-to-moderate basophilic cytoplasm. Cytoplasmic and/or nuclear vacuoles were also seen, more prominent in Diff-Quik-stained, air-dried smears. These cases demonstrate the importance of recognizing the cytologic features of Burkitt's lymphoma, as serous fluid may be the initial diagnostic specimen.

Association of Epstein-Barr virus with leiomyosarcomas in young people with AIDS

BACKGROUND

Children with the acquired immunodeficiency syndrome (AIDS) have an unusually high incidence of smooth-muscle tumors (leiomyomas and leiomyosarcomas) in addition to malignant lymphomas. We tested the hypothesis that the smooth-muscle tumors in these children are associated with the Epstein-Barr virus (EBV).

METHODS

Tissue specimens of five leiomyosarcomas and two leiomyomas from six children with AIDS were studied for evidence of the human immunodeficiency virus (HIV) and EBV by in situ hybridization and quantitative polymerase chain reaction (PCR). Comparison specimens included samples of leiomyosarcoma and leiomyoma from HIV-negative children. EBV clonality of leiomyosarcomas was determined by Southern blot analysis with oligonucleotide probes for EBV terminal-repeat fragments. Tumor specimens were tested by immunoperoxidase staining for infiltration by B lymphocytes and expression of the EBV receptor. Serologic testing for EBV was performed.

RESULTS

In situ hybridization showed EBV genomes in all muscle cells of the five leiomyosarcomas and the two leiomyomas from the six HIV-infected children. Quantitative PCR demonstrated strikingly high levels of EBV in tumor tissue, with as many as 4.3 genome copies per cell. Two colonic leiomyosarcomas obtained from different sites at different times from one patient contained different episomal EBV clones, signifying the presence of distinct monoclonal EBV-related tumors. We found biclonal EBV infection in the leiomyosarcoma of another patient. No EBV was detected in normal muscle or tumor specimens from HIV-negative patients. Immunostaining for the EBV receptor was strongly positive in six of the seven leiomyomas and leiomyosarcomas from the patients with AIDS.

CONCLUSIONS

EBV can infect smooth-muscle cells, at least in patients with AIDS, and it may contribute to the pathogenesis of leiomyomas and leiomyosarcomas in children with AIDS. EBV seems to play no part in smooth-muscle tumors in HIV-negative children.

Reversal of Indian childhood cirrhosis by D-penicillamine therapy

Serial liver biopsy changes have been reviewed in 30 patients with Indian childhood cirrhosis (ICC) who were randomly allocated to receive treatment with penicillamine in a dose of 20 mg/kg/day, 10 of whom also received prednisolone, and five receiving placebo. The latter died within 185 (mean, 149) days of starting treatment. Nine receiving penicillamine died within 540 (mean, 338) days, but the remainder are well 5.1-9.3 years after commencing treatment. Initial biopsies showed severe hepatocellular injury, pericellular fibrosis, inflammatory infiltration, and orcein-staining granules. Second biopsies taken within 6 months of starting penicillamine usually showed persistence of inflammation and an increase in nodularity with thick and thin active septae. Subsequently the appearances were of an inactive micronodular cirrhosis, with reduction in septal inflammatory infiltrate, hepatocellular injury, and intensity of orcein staining. This further improved to a stage of incomplete fibrous septae. The last liver biopsies at 6-60 months (in 21 survivors) showed almost normal histology in four, incomplete fibrous septae in five, and inactive micronodular cirrhosis with thin septae in 12. Mean liver copper concentrations decreased from 1,407 (SEM, 121) micrograms/g at presentation to 925 (183), 317 (100), and 127 (35) at 6, 6-18, and > 18 months after starting treatment. By contrast, a second biopsy taken in the 6 months after diagnosis in placebo-treated children showed persistence of ICC with increase in inflammation, fibrosis, and orcein staining.

Veno-occlusive disease of the liver induced by low-dose cyclophosphamide

A 2-yr-old child with idiopathic pulmonary hemosiderosis and autoimmune thrombocytopenia developed hepatic veno-occlusive disease after being treated with long-term, low-dose cyclophosphamide. The authors believe that the injury was induced by cyclophosphamide. Although transplant dosages of cyclophosphamide alone or in conjunction with other drugs have been shown to induce hepatic venocclusive disease, this is the first case of hepatic venocclusive disease associated with nontransplant dosages of cyclophosphamide. Histopathologically, the injury was characterized by occlusive lesions of intrahepatic veins, both the terminal hepatic venules and portal veins branches, together with necrosis (predominately involving Zones 3 and 2) and hemorrhages. An added risk factor could have been release of platelet-derived growth factor that in turn activated and promoted proliferation of fibroblasts and smooth muscle cells in the vessels. Previously reported cases of cyclophosphamide-related injury are reviewed.

Pathology of AIDS in children

AIDS in children is a multisystem disease. The various infections, degenerative, proliferative and vascular lesions can be classified into three categories based on the known, presumed or undetermined pathogenesis. The primary lesions are due to HIV infection. The associated lesions are related to direct or indirect sequelae of HIV infection or its treatment. The third category is of lesions of undetermined pathogenesis. The pediatric pathologist plays an important role in the study and management of AIDS by demonstrating new pathologic lesions, by making the etiologic diagnosis of infection in children with AIDS, and by providing clinicopathologic correlation which leads to better understanding of the disease process and its natural history. Diagnosis of neoplastic disorders is also made by the pathologist. There is a dearth of systematic pathologic study of AIDS in children in developing countries. Although no basic differences between pathologic lesions in pediatric AIDS in Western countries, and in developing countries is expected, such a study would lead to better understanding and better management of the disorder as it affects children from the developing countries.

Pathology of neuroblastic tumors

Histogenesis, basic histologic features, nomenclature, and criteria for diagnosis and prognostic classifications based on morphological features of neuroblastic tumors (NTs) are described. NTs that arise from neuroectodermal cells of the adrenal medulla and sympathetic ganglia recapitulate the development of sympathetic ganglion. The following three basic types of NTs are recognized: neuroblastoma (NBs) and ganglioneuroblastomas (GNBs) and ganglioneuromas (GNs). NBs can be undifferentiated, poorly differentiated or differentiating; GNBs have the following three subtypes. (1) nodular, (2) intermixed, and (3) borderline. The conventional and recommended terminology and Shimada terminology of NTs are described (Tables 1 and 2). There are three basic pathologic components of NTs, neuroblastomatous, ganglioneuromatous, and intermediate components (Figs 3, 5, and 7). There are two major prognostic classifications based on morphological features of NTs, Shimada classification and histologic grading (Tables 3 and 4).

FNA biopsy of small round cell tumors of childhood: cytomorphologic features and the role of ancillary studies

Pediatric tumors which are conventionally considered to be small round cell tumors (SRCTs) include the prototypical neuroblastoma as well as rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), malignant lymphoma, and primitive neuroectodermal tumor (PNET). Other malignancies may be considered in the differential diagnosis such as small-cell osteogenic sarcoma, undifferentiated (anaplastic) hepatoblastoma, granulocytic sarcoma, blastemal type Wilms' tumor, and desmoplastic small-cell tumor of the peritoneum. The cytomorphologic features of conventional SRCTs is presented as well as the utility of ancillary studies performed on the aspirated material in making a specific and correct diagnosis. The role of the immediate cytologic assessment of the aspirate is stress, since this is a critical step in formulating an initial diagnostic impression that should prompt the need for additional material for pertinent ancillary studies. Although challenging, FNA cytology of SRCTs of childhood can be diagnostic in the majority of cases, allowing specific therapy to be given to patients with unresectable SRCTs without a tissue biopsy as well as documenting recurrent and/or metastatic disease.

Multicentric Castleman's disease in a child with prominent thymic involvement: a case report and brief review of the literature

A fatal case of multicentric Castleman's disease (giant lymph node hyperplasia) with prominent thymic involvement in a 12-yr-old girl is presented. Multicentric Castleman's disease is a poorly understood lymphoproliferative disorder generally occurring in elderly individuals. To our knowledge, this is the first case in the English literature of multicentric Castleman's disease in a child. Thymic involvement has not been described previously in the multicentric variant or in a child. Besides the characteristic findings of Castleman's disease (CD), such as hyaline-vascular follicles and a prominent plasmacytic infiltrate, the thymus was also marked by prominent epithelial hyperplasia in the medulla. The clinical and pathologic findings are presented with a review of the literature, particularly thymic involvement in CD and CD in the pediatric population.

Cytomorphology of familial hemophagocytic syndrome

Familial hemophagocytic syndrome (FHS) is a rare, fatal disorder of childhood demonstrating failure to thrive, fever, hepatosplenomegaly (HSM), recurrent infections, pancytopenia, and histologically, the infiltration of reticuloendothelial organs by benign-appearing histiocytes demonstrating hemophagocytosis. We report two fatal cases of FHS including a 3 year-old female who underwent fine-needle aspiration (FNA) biopsy of the liver in the initial workup of the disease (case 1) and an 8 month-old boy with ascites and HSM having peritoneal fluid cytology submitted as the first specimen for morphologic examination (case 2). In case 1, the FNA cytologic findings included benign hepatocytes and scattered mature and reactive lymphocytes and histiocytes. The histiocytes demonstrated fine to coarse cytoplasmic vacuoles and erythrophagocytosis. The diagnosis was confirmed at autopsy which revealed extensive lymphohistiocytic infiltrates in various organs including the central nervous system. In case 2, the peritoneal fluid cytology specimen contained numerous atypical and degenerating mononuclear lymphoreticular cells which were dispersed as a single cell suspension admixed with infrequent mesothelial elements; hemophagocytosis was not appreciated. Subsequent liver biopsy revealed portal tracts and sinusoids infiltrated by benign but atypical histiocytes with hemophagocytosis. Bone marrow examination and then autopsy confirmed the diagnosis of FHS. A panel of immunocytochemical studies was performed in the first case which was an aid in confirming the diagnosis of FHS and ultrastructural examination of the second case revealed well-developed erythrophagocytosis. Both patients had siblings who died of FHS. Although not diagnostic, cytomorphology may suggest FHS.

Correlation between morphologic and other prognostic markers of neuroblastoma. A study of histologic grade, DNA index, N-myc gene copy number, and lactic dehydrogenase in patients in the Pediatric Oncology Group

BACKGROUND

Histologic grades (HG), N-myc (NM) gene copy number, DNA index (DI), and serum lactic dehydrogenase (LDH) have been shown to be related to prognosis in neuroblastoma. The relationship between HG and nonmorphologic prognostic markers has not been investigated previously.

METHODS

Each prognostic marker was determined independently and without the knowledge of clinical features and outcome by different investigators in 275 (HG), 96 of 275 (DI), 94 of 275 (NM), and 224 of 275 patients (LDH) with neuroblastoma by methods described previously. Patients younger than 2 years of age were included in the analysis for DI. Patients of all ages were included in the analysis of HG, NM, and LDH.

RESULTS

A statistically significant association of low HG (1 and 2) was found with DI of more than 1 (hyperdiploid), single copy of NM gene per haploid genome, and an LDH of less than 1500 IU/l (P value for each, < 0.001), factors that are associated with better prognosis. High HG was associated with DI of 1 (diploidy), amplified NM gene, and an LDH of 1500 or more, factors that are associated with aggressive behavior.

CONCLUSION

The value of HG is strengthened by its statistically significant association with features that reflect tumor cell biology of neuroblastoma. In view of the tissue sample size required for determination of HG, consideration should be given to obtaining such a sample in as many patients as is feasible if there is no contraindication to surgery. Nonmorphologic prognostic markers, when used in concert with HG, would provide a basis for individualized risk-specific therapy of this disease.