Fine-needle aspiration biopsy of small round blue cell tumors of childhood

Extraskeletal ewing's sarcoma on hard palate biltaerally: A rare case report

Ewing Sarcoma belongs to the category of undifferentiated blue small round cell tumour and its origin has been traced to be that from inside of the bone, but can also arise in soft tissues (extraosseous form). These lesions belong to the category of round cell tumours, which includes a varied range of tumours. This category, although found in other extremities and thoracic regions, head and neck region have been reported to have less number of tumours, in addition to that the soft tissue counterparts are even scarcely reported. Thereby, this case reports represents a soft tissue counterpart of Ewings Sarcoma on the hard palate, which not only extends unilaterally but extends bilaterally.

Categorizing Malignant Small Round Cell Tumors in Aspiration Cytology: An Institutional Experience

Aim and Objectives

The study aims to categorize malignant small round cell tumors (MSRCTs) originating in various sites of the body with the objective of utilization of cytomorphological features and ancillary techniques.

Study Design

It is a cross-sectional study conducted over a time span of 3 years (2017-2020). 33 cases of tumors with round cell morphology were evaluated by fine needle aspiration cytology (FNAC).

Materials and Methods

The application of cell block preparation supported by immunohistochemistry aided in the categorization of 23 cases with definite diagnosis and the rest were reported as MSRCTs.

Results

Among the categorized 23/33 cases, the most common diagnosis was Ewing's sarcoma (7/23) followed by 6 cases of lymphoma. There were 2 cases each of rhabdomyosarcoma and Langerhans cell histiocytosis (LCH) and 1 case each of neuroblastoma, desmoplastic small round cell tumor (DSRCT), myeloid sarcoma, neuroendocrine tumor of pancreas, plasmacytoma, and small cell carcinoma. Histopathology confirmation was available in 24/33 cases. Among the categorized tumors (23/33), biopsy correlation was available in 19 cases, of which concordant result was seen in 17 cases (89.47%), which were 6 cases of lymphoma, 5 cases of Ewing's sarcoma (EWS), 2 of rhabdomyosarcoma, and 1 each of neuroblastoma, small cell carcinoma, DSRCT, and LCH. Discordant result was seen in one case of rhabdomyosarcoma and a case of synovial sarcoma reported as extraskeletal EWS in cytology. Out of the uncategorized cases reported as MSRTCs, histopathology was available in 5 cases which were diagnosed as rhabdomyosarcoma (1 cases), lymphoma (1 case), amelanotic melanoma (1 case), and extraskeletal EWS (2 cases).

Conclusion

Categorization of MSRCTs should be done to implement appropriate therapeutic protocol. FNAC provides a rapid diagnosis contributing immensely for the timely management of the patient. Detailed cytomorphological evaluation serves as a guide for further evaluation by ancillary techniques leading to definitive diagnosis.

Doing More with Less: Fine Needle Aspiration Cytology in Pediatric Neoplasms

Background:

Cancer is one of the leading causes of death in the pediatric age group following infections. Among the diagnostic modalities, fine needle aspiration cytology (FNAC) is increasingly recognized as it permits rapid diagnosis with low cost and complication. In this study, we emphasize the diagnostic value of FNAC and describe the cytomorphological spectrum of tumors diagnosed on FNAC in pediatric patients with or without the aid of ancillary tests.

Materials and Methods:

This retrospective study included a total of 614 patients under the age of 15 years for whom fine needle aspiration (FNA) was done during a period of 3 years with or without guidance. The cytology smears were reviewed, and the morphological spectrum was analyzed with the ancillary studies.

Results:

Aspirates from children constituted around 3.5% of the total FNAC performed in our Institute. Of the 614 cases, 336 were male, and 278 were female with age under 15 years. Neoplastic cases constituted around 72%, which included benign (2%) and malignant (98%) tumors. The spectrum include hematolymphoid neoplasms in 39.3%, small round cell tumors (SRCT) in 24.9%, Wilms tumor in 9.2%, germ cell tumors in 4.8%, spindle cell neoplasms in 4.8%, hepatoblastoma in 3.2%, and osteosarcoma in 3% of the cases. The metastatic lesions constituted 8.1% of the cases diagnosed by FNA.

Conclusion:

FNA proves to be a reliable and efficien modality in diagnosing pediatric neoplasms in the hands of a skilled cytopathologist.

Pediatric neuroblastic tumors: A critical evaluation of cytomorphological features for risk stratification on aspiration cytology

BACKGROUND

Neuroblastic tumor (NT) is the most common extracranial solid tumor of childhood with variable outcome which again depends on risk stratification related to distinct biology of the tumor. The use of fine-needle aspiration (FNA) material for evaluation of cytomorphological parameters and risk stratification in NTs using cytology prognostic score (PS) is limited in routine practice.

METHODS

We reviewed 38 FNA cytology cases diagnosed as pediatric small round cell tumor between time period June 2017 to December 2019 for clinical, cytomorphological and immunohistochemical features.

RESULTS

Ten out of 38 small round cell tumors were NTs. All 10 cases were further subclassified according to International Neuroblastoma Pathology Classification into undifferentiated neuroblastoma (n = 1), poorly differentiated neuroblastoma (n = 5), differentiating neuroblastoma (n = 2), and ganglioneuroblastoma (n = 2). Cytologic PS was done using the morphological criteria as described previously in literature. The patients were divided into favorable and unfavorable cytomorphological prognostic categories with a cut off scoring of 12. A score of more than 12 is associated with high risk morphology and advanced stage. All cases with PS > 12 (n-4) (unfavorable cytomorphology) had a poor outcome compared to six patients with PS < 12 (n-6) (favorable cytomorphology).

CONCLUSION

Aspiration cytology can be used as a first line investigation to evaluate the cytomorphological features for risk stratification and diagnosis in patients with NTs using cytological prognostic scoring system. A larger multi-centric validation study necessitates for cytological risk stratification.

Round Cell Tumors: Classification and Immunohistochemistry

Round cell tumors as the name suggest are comprised round cells with increased nuclear-cytoplasmic ratio. This group of tumor includes entities such as peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilms' tumor, and desmoplastic small round cell tumor. These round cells tumors are characterized by typical histological pattern, immunohistochemical, and electron microscopic features that can help in differential diagnosis. The present article describes the classification and explains the histopathology and immunohistochemistry of some important round cell tumors.

Fine needle aspiration cytology of non-hematological neoplasms in pediatric age group: Our experience

Background:

The role of aspiration cytology has largely been ignored in pediatric population. The present study was undertaken to evaluate the role of fine needle aspiration cytology (FNAC) in non-hematological neoplasms in children in our institution, which is a rural tertiary care center.

Materials and Methods:

A total of 88 cases of non-hematological pediatric mass lesions were studied in which cytopathological diagnosis could be corroborated with histopathology.

Results:

Out of all the cases, 70 (80%) cases were benign tumors and 18 (20%) were malignant tumors. Fibroadenoma (37.9%) comprised the majority of cases in the benign category while small round cell tumors (SRCTs) (44.4%) comprised the majority of cases in the malignant category. Definite diagnosis could be offered based on the cytomorphology in 79.5% cases, while in 20.5% of cases only a broad cytological classification could be offered. Among the malignant lesions, FNAC showed 100% sensitivity while a specific diagnosis was made in 90% of cases.

Conclusion:

FNAC proved to be a rapid and fairly accurate tool in diagnosing non-hematological tumors in the pediatric age group.

Malignant small round cell tumors

Malignant small round cell tumors are characterised by small, round, relatively undifferentiated cells. They generally include Ewing's sarcoma, peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, retinoblastoma, neuroblastoma, hepatoblastoma, and nephroblastoma or Wilms’ tumor. Other differential diagnoses of small round cell tumors include small cell osteogenic sarcoma, undifferentiated hepatoblastoma, granulocytic sarcoma, and intraabdominal desmoplastic small round cell tumor. Differential diagnosis of small round cell tumors is particularly difficult due to their undifferentiated or primitive character. Tumors that show good differentiation are generally easy to diagnose, but when a tumor is poorly differentiated, identification of the diagnostic, morphological features is difficult and therefore, no definitive diagnosis may be possible. As seen in several study reports, fine needle aspiration cytology (FNAC) has become an important modality of diagnosis for these tumors. The technique yields adequate numbers of dissociated, viable cells, making it ideally suitable for ancillary techniques. Typically, a multimodal approach is employed and the principal ancillary techniques that have been found to be useful in classification are immunohistochemistry and immunophenotyping by flow cytometry, reverse transcriptase polymerase chain reaction (RT-PCR), fluorescence in situ hybridization (FISH), and electron microscopy. However, the recent characterization of chromosomal breakpoints and the corresponding genes involved in malignant small round cell tumors means that it is possible to use molecular genetic approaches for detection.

Reverse transcriptase-polymerase chain reaction as an ancillary molecular technique in the diagnosis of small blue round cell tumors by fine-needle aspiration cytology

We evaluated the feasibility and usefulness of reverse transcriptase-polymerase chain reaction (RT-PCR) on fine-needle aspirates for categorization of small blue round cell tumors (SBRCTs). A total of 51 cases, including 25 Ewing sarcoma/peripheral primitive neuroectodermal tumors (PNETs), 11 rhabdomyosarcomas, 13 neuroblastomas, and 2 desmoplastic small round cell tumors (DSRCTs) were analyzed. The detection of the EWS-FLI1 (20/25) and EWS-ERG (4/25) fusion transcripts resolved 24 of 25 cases of Ewing sarcoma/PNET. The PAX3/7-FKHR fusion transcript was detected in 2 of 4 cases of alveolar rhabdomyosarcoma and the EWS-WT1 transcript in both cases of DSRCT. Tyrosine hydroxylase and 3,4-dihydroxyphenylalanine (dopa) decarboxylase transcripts were demonstrated in 10 of 13 cases of neuroblastoma. In comparison, immunocytochemical analysis resolved 19 (76%) of 25 Ewing sarcomas, 9 (82%) of 11 rhabdomyosarcomas, 6 (46%) of 13 neuroblastomas, and 1 (50%) of 2 DSRCTs. Overall, RT-PCR resolved 38 (86%) of 44 vs 35 (69%) of 51 cases by immunocytochemical analysis. RT-PCR is easily applied to fine-needle aspirates of SBRCT and greatly facilitates accurate tumor typing.

Cytological evaluation of head and neck tumors in children—A pattern analysis

A total of 135 pediatric head and neck tumors diagnosed in our institute were reviewed with a view to elucidate the overall cytological patterns and analyze the important cytological features. Ninety-four tumors (69.6%) were aspirated for a primary diagnosis, and in 41 (30.4%) cases, fine-needle aspiration cytology was performed to document relapse, recurrence or a metastasis. Among the 94 tumors aspirated for a primary diagnosis, 66 cases (70.2%) were accurately diagnosed, in 22 cases (23.4%) a broad working diagnosis was offered, and 6 cases (6.4%) were misdiagnosed. The accuracy rate was higher (79.3%) when relapse-recurrent and metastatic tumors were included. The smears were broadly divided into six patterns, viz. round cell, epithelial, anaplastic, giant cell, mixed inflammatory, and spindle cell patterns. The round cell pattern was the most frequent one encountered in this group. The cytological features that stood the test of variability were lymphoglandular bodies and a noncohesive cell population in hematolymphoid malignancies, pale chromatin and cytoplasmic vacuoles in primitive neuroectodermal tumor/Ewing's sarcoma (PNET/ES), neuropil and rosettes in neuroblastoma, and plasmacytoid rhabdomyoblasts in rhabdomyosarcoma. A fairly good accuracy was seen in the diagnosis of metastatic undifferentiated carcinoma and anaplastic lymphoma, but the giant-cell and spindle-cell tumors continued to pose a problem in diagnosis. Ancillary techniques such as immunocytochemistry and electron microscopy applied in limited cases helped evaluate Langerhans cell histiocytosis, alveolar rhabdomyosarcoma, and the PNET/ES family of tumors.

Fine-needle aspiration biopsy in pediatric oncology patients: a review of experience with 829 patients (899 biopsies)

The authors review their 20-year (1985-2004) experience with fine-needle aspiration biopsy (FNAB) in 829 children (all but 1 younger than 18 years), from whom 899 samples were obtained. All patients presented with clinical data suggesting malignancy. The procedure followed standard methods (22- to 24-gauge needle; mean of six alcohol-fixed and/or air-dried, H&E- or Giemsa-like-stained smears/procedure; leftover clots processed as a biopsy). Interpretation of cytologic smears was performed taking into consideration the clinical, laboratory, and imaging data. Smears diagnosed as positive for malignant cells were reported in 510 samples (56.7%) (463 patients); 1.89% of the smears were found inadequate for diagnosis. Positive for malignancy cases included 467 primary tumors, 52% of which were localized to the abdomen. NMYC status was determined on neuroblastoma samples by fluorescent in situ hybridization. Overall sensitivity of the procedure was 98% (500/510 FNAB); specificity was 92.6% (463/500 FNAB); positive predictive value was 1 and negative predictive value was 0.99. All FNABs diagnosed as benign tumors or inflammatory lesions correlated with histology and/or clinical outcome. FNAB proved to be highly cost-effective, avoiding a surgical biopsy. The procedure was found to be extremely helpful when deciding on preoperative chemotherapy.

Fine-needle aspiration of adult small-round-cell tumors studied with flow cytometry

Immunophenotypic study is critical for the diagnosis of adult small-round-cell tumors (SRCTs). We describe three patients with Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) and one patient with neuroblastoma in which flow cytometry immunophenotyping (FCI) on the fine-needle aspirate (FNA) and bone marrow aspirate (BMA) demonstrated an abnormal population of cells that were CD45(-) and CD16/CD56(+). Four patients with mean age of 30 years, three male and one female, clinically suspicious for a lymphoma or SRCT are described. FNA, BMA, and biopsy specimens were obtained for routine cytologic and histologic evaluation. Fresh tissue was studied by FCI. In all cases, the cytology smears showed small cells with round nuclei, slightly irregular nuclear membranes, fine chromatin, and scant cytoplasm. FCI showed CD16/56(+) and CD45(-) neoplastic cells in all cases. In one case, 76% of these cells were CD99(+). The diagnoses of ES/PNET were confirmed by immunohistochemical, ultrastructural, and cytogenetic studies. ES/PNET in FNA and BMA can be efficiently and rapidly diagnosed by combining cytologic examination with FCI using a panel including CD45, CD16/56, and CD99.

Cytological features of epithelioid mesenchymal neoplasms: A study of 21 cases

Epithelioid mesenchymal neoplasms (EMNs) are rare tumors that share cytological, histological, and immunohistochemical features with epithelial tumors. It is important to distinguish EMNs from epithelial tumors in cytology specimens due to their different clinical management and prognosis. The cytomorphological features of histologically confirmed EMN were reviewed. Twenty-one cytological specimens of EMN were evaluated and characterized by polygonal cells with moderate to abundant dense cytoplasm, prominent nucleoli, and pleomorphism. Additional findings included the presence of a distinct population of spindle cells, hemosiderin-containing cells, multinucleated cells, and granuloma-like structures in selected cases. Cytokeratin immunoreactivity was seen in two cases and was negative in one case. This study shows that the cytological features of EMNs and epithelial tumors overlap; nonetheless, some features are more helpful in suggesting EMN. A panel of immunocytochemical studies must include specific mesenchymal markers to avoid a misdiagnosis of carcinoma in cases of cytokeratin-positive EMN.

Diagnosing childhood tumors: A review of 147 cutting needle biopsies in 110 children

BACKGROUND/PURPOSE

The aims of this study were to evaluate the diagnostic accuracy and safety of cutting needle biopsy for diagnosis in children with tumors suspected for malignancy.

METHODS

Medical records and biopsy slides recorded from 1988 to 1999 were reviewed. One hundred ten patients had undergone a total of 147 cutting needle biopsies. The biopsy was performed under ultrasound guidance, using a 1.2-mm (18 gauge) Biopsy-cut biopsy needle. The diagnoses were benign tumors (n = 8), malignant tumors (n = 84), and nonneoplastic diseases (n = 18), with repeat biopsy performed in 24 patients.

RESULTS

The diagnostic accuracy of cutting needle biopsies was 89% (131 of 147). The accuracy for pretreatment diagnosis was 88% (102 of 116), and for confirming or excluding a recurrence or metastasis 93% (26 of 28). The sensitivity of this method was 82% (86 of 105), and the positive predictive value 99% (86 of 87). Nondiagnostic cutting needle biopsy (n = 16) was not related to the age of the patient, experience of the radiologist, number of needle insertions, or site of puncture. No patient exhibited tumor growth along the needle tract. Complications occurred in 10 cases (7%) and pain in 20 (14%).

CONCLUSION

Cutting needle biopsy is an accurate and safe procedure with a low learning threshold that is recommended for diagnosing malignancies in childhood.

Fine needle aspiration cytology in the diagnosis and management of children and adolescents with Ewing sarcoma and peripheral primitive neuroectodermal tumor

PURPOSE

The utility of fine needle aspiration cytology (FNAC) in conjunction with immunocytochemistry in the diagnosis of Ewing sarcoma and peripheral primitive neuroectodermal tumor, the Ewing family of tumors (EFT), is retrospectively described.

PATIENTS AND METHODS

During a 10-year period 24 children and adolescents were diagnosed at Karolinska Hospital to have EFT of bone or soft tissue using FNAC. Criteria for diagnosis was based on cytomorphology combined with immunocytochemistry. The median age was 14.1 years (range 0.7-20.2). FNAC was performed within a median time of 1 day after referral.

RESULTS

Forty aspiration procedures were performed, 24 at primary work up in 23 patients and 16 at suspected relapses in 10 patients. A primary cytologic diagnosis of EFT was obtained in 22 of 23 cases. In nine cases with primary disease there was no histologic confirmation. Two tumors were on FNAC diagnosed as neuroblastoma versus EFT, and EFT, respectively. Histopathology on resected tumor tissue from these patients showed EFT and small cell osteosarcoma, respectively. Suspected relapse was found to be positive at five and negative at 11 occasions. Immunocytochemistry was positive for CD45 (LCA) in 0/12, for desmin in 2/21, for MIC2 in 15/15, for NB84 in 1/3, for NFP in 7/7, for NSE in 12/18, for S-100 in 4/11 and for vimentin in 18/19.

CONCLUSIONS

The results show that FNAC together with immunocytochemistry is a rapid, physically atraumatic and accurate method in diagnosing both primary EFT of bone and soft tissue as well as relapses.

Changing role of fine-needle aspiration in the evaluation of pediatric masses

This study examines changes in the use of fine-needle aspiration (FNA) in the pediatric population in the past 14 yr at the University of California, Davis Medical Center. Pediatric FNAs from two 7-yr periods were compared regarding percentage of satisfactory cases and cases with a previous history of cancer, sensitivity, specificity, type of general diagnostic category, ratio of benign to malignant diagnoses, and sources of diagnostic error. Changes in the later 7-yr period included decrease in the percentage of round cell lesions with an increase in spindle cell and epithelial/epithelioid lesions, fewer patients with a prior history of cancer, and a marked increase in benign to malignant ratio. These changes illustrate that FNA is being used more commonly in the general pediatric population, and that the types of lesions seen in this population are not very dissimilar to those seen in adults.

Unusual presentation of granulocytic sarcoma in the breast: a case report and review of the literature

This is a case of granulocytic sarcoma presenting as bilateral breast masses in a 40-yr-old woman with concurrent unsuspected chronic myeloid leukemia diagnosed by fine-needle aspiration. The granulocytic differentiation was recognized on Diff-Quik-stained cytology smears and confirmed rapidly on flow cytometry on the same day. The breast has been reported to be an uncommon site for granulocytic sarcoma. We found that 38.8% of granulocytic sarcomas diagnosed by fine-needle aspiration in the English-language literature occurred in the breast. In the absence of clinical history or hematological abnormality, granulocytic sarcoma may be misdiagnosed, depending on the degree of myeloid differentiation present within the tumor. The differential diagnosis includes large-cell non-Hodgkin's lymphoma, lobular carcinoma of the breast, undifferentiated carcinoma, malignant melanoma, extramedullary hemopoiesis and inflammation. The key morphological features and useful ancillary tests are discussed.

Assessment of percutaneous fine needle aspiration cytology as a technique to provide diagnostic and prognostic information in neuroblastoma

The International Neuroblastoma Staging System (INSS) criteria for diagnosis requires an unequivocal pathological diagnosis and favours the identification of prognostic markers in the samples. Surgical biopsies of the primary tumour and bone marrow (BM) sampling in metastatic disease constitute the major sources of tumour material for the laboratory. We analysed the possibility of percutaneous fine needle aspiration cytology (FNAC) constituting an alternative procedure to the conventional technique of sampling of the primary tumour in children with advanced neuroblastoma. From July 1987 through July 1998, 64 consecutive children suspected of having advanced neuroblastoma and referred to our institution underwent percutaneous FNAC of deeply located tumours. FNAC was performed using 22-gauge needles under ultrasound guidance, before any chemotherapy and within the first days following admission. No complication occurred after FNAC. The median number of the extracted tumour cells was 2.3x10(6) (range: 0-40.6x10(6)). Cytology analysis was possible in 59/64 cases (92%) and immunocytochemistry in 56/64 (88%) allowing confirmation of the diagnosis. N-Myc analysis was available in 46/64 (72%). In addition, the presence of a partial deletion of chromosome 1p (del 1p) was assessed, since 1992, in 24/47 cases (51%), where enough cells were available. FNAC of deeply located advanced neuroblastoma is safe and information is available in a few hours after admission. The provided material is reliable for confirmation of diagnosis and analysis of biological prognostic markers in the majority of cases. More invasive tumour sampling procedures are required only in selected cases.

Childhood tumors

Pediatric solid tumors represent a distinct set of malignancies of embryonal origin whose incidence peaks in the first years of life. Specific genetic anomalies with pathogenic significance, which have helped to define the diagnosis better and to improve the prognosis of children with these tumors, recently have been discovered. Survival of children with solid tumors also has improved significantly because of effective multidisciplinary care, which, in this case, always involves chemotherapy and surgery. These favorable results require that children with these diseases are referred and treated at institutions that have multidisciplinary teams and the infrastructure and expertise for caring for these children. Diagnostic and therapeutic principles for the most common childhood solid tumors are discussed in this article, with an emphasis on surgical procedures.

Diagnosis of posttransplant granulocytic sarcoma by fine-needle aspiration cytology and flow cytometry

We describe a patient who developed granulocytic sarcomas of the mesentery and breast approximately 4 yrs following an allogenic bone marrow transplantation for acute myeloblastic leukemia. The diagnosis was made by a combination of fine-needle aspiration cytology and flow cytometry. The differential diagnoses of localized masses in posttransplant patients and how the combination of fine-needle aspiration cytology and flow cytometry may be used are discussed.

The clinical use of fine needle aspiration cytology for diagnosis and management of children with neuroblastic tumours

This study presents the results of fine needle aspiration cytology in a series of 26 consecutive children with neuroblastic tumours. The cytological spectrum varied from undifferentiated small tumour cells to mature ganglion cells in a fibrillar background. In 24 children with neuroblastic tumours at onset the cytological diagnosis was correct in 21 cases, whereas two aspirates yielded nondiagnostic necrotic material and a fibrillar material without tumour cells, respectively. One necrotic lymph node aspirate was initially incorrectly diagnosed as lymphoma, but the diagnosis was later revised to neuroblastoma. Suspected signs of disease progression or relapses were confirmed (n = 9) or ruled out (n = 1) using aspiration cytology. The diagnostic accuracy in the complete series was 97% (31/32) in cases with adequate smears. Immunocytochemistry confirmed the cytological diagnosis in 14 of 15 cases and was decisive in one. Elevated catecholamine metabolites in urine was detected in all children with a cytological diagnosis of neuroblastoma. General anaesthesia was only performed when coincidental invasive investigations (n = 13) were to be carried out or if the aspiration was intrathoracic (n = 6). It is concluded that aspiration cytology in conjunction with immunocytochemistry offers a safe, rapid and accurate diagnostic method which may be useful, together with analyses of catecholamine metabolites in urine, in the clinical management of children with neuroblastic tumours.

Fine needle aspiration biopsy in children

BACKGROUND

Fine needle biopsy (FNB) in children has been slow to gain acceptance compared with the use of the technique in adults where it is regarded as standard clinical practice in screening significant lymphadenopathy and suspicious masses. We report our early experience with FNB in the paediatric population.

METHODS

Fifty-two biopsies were performed between June 1991 and June 1993. The age of the children ranged from 6 months to 14 years (median 2 years, mean 5 years).

RESULTS

A definite diagnosis on cytology alone was obtained in 67%. The pathologist was certain of malignant or nonmalignant potential in 79% (67% benign and 12% malignant) and unsure in 21% (17% benign and 4% malignant). There were no false positive or false negative diagnoses of malignancy. Surgical excision or biopsy was performed in 33%. Fine needle biopsy assisted in planning surgery in 12%. Surgery was necessary for a definite diagnosis in 21% and FNB assisted 42% of the patients to avoid surgery altogether.

CONCLUSIONS

Fine needle biopsy is simple, minimally invasive and useful in the evaluation of children with suspicious lymph nodes and masses.

Cytologic characteristics of peripheral neuroectodermal tumors in fine-needle aspiration smears: a retrospective study of three pediatric cases

Cytologic diagnosis of peripheral neuroectodermal tumors (PNT) on fine-needle aspiration (FNA) smears represents a challenge to the cytopathologist. Usually ancillary studies are used to achieve definitive diagnosis. We retrospectively examined FNA material from three cases of PNT with the aim of identifying their features. Positive and negative cytologic findings were recognized. Positive features for PNT included the presence of: rather uniform appearance of the cells, which display scant but almost always-present perinuclear clear cytoplasm (suggesting a bland epithelial tumor); nuclei with distinctively smooth nuclear membrane contour, finely granular chromatin, and one or two small nucleoli (suggesting neuroendocrine anlage); and organization of the cells singly or in cohesive clusters. Negative findings included the absence of: frequent mitotic figures, large nucleoli, nuclear pleomorphism, cellular debris, histiocytes, and polymorphonuclear leucocytes. The smears appeared clean, with small, uniform cells having features suggesting a neuroendocrine epithelial tumor. These findings may prove useful for accurate cytologic diagnosis and differentiation of PNT from other small blue round cell tumours (SBRCT) of soft tissues without the use of ancillary studies since, when properly evaluated, cytomorphology of the latter group of tumors is more heterogeneous than generally believed.

Fine-needle biopsy of pediatric lesions: a three-year study in an outpatient biopsy clinic

Diagnostic Cytology Laboratory, Inc., has an outpatient Fine Needle Biopsy Clinic, which evaluated 7,487 fine-needle biopsies (FNB) from January 1989 to February 1992. Two hundred eighty-eight (3.8%) of these specimens were collected from patients 19 years old or younger and this represents the largest study of this population in the scientific literature. The majority of these specimens were obtained from palpable masses in the head and neck region [lymph nodes (58.3%), thyroid (7.6%), and salivary gland (5.2%)] while a smaller number were collected from miscellaneous soft tissue (18.8%) and breast masses (10.1%). Thirteen (4.5%) (from 12 patients) were diagnosed as malignant by FNB and 275 (95.5%) (264 patients) were benign by FNB. This benign:malignant ratio (22:1) is significantly higher than has been reported from tertiary care institutions and is a reflection of the difference of this outpatient population. Two hundred nine of 276 patients (75.7%) had adequate follow-up, including 137 (49.6%) patients followed by observation, 48 (17.4%) patients followed by surgical biopsy, and 24 (8.7%) patients followed by some other modality: imaging studies, flow cytometry, or treatment. There was a single false positive diagnosis (a pilomatrixoma) and one (1) false negative interpretation (a cystic acinic cell carcinoma) resulting in a diagnostic sensitivity of 92.3% and a specificity of 99.6%. The positive predictive value was 92.3%, the negative predictive value was 99.6%, and the test efficiency was 99.3%. The utility, cost-effectiveness and uniqueness of the clinic population is discussed.

Malignant peripheral neuroectodermal tumors in urology

During the past few years, a new tumor type has emerged in the pediatric and adolescent group of cancer patients, which has been designated malignant peripheral neuroectodermal tumor (MPNT). This tumor has some clinical and pathological signs in common with either soft-tissue sarcomas or classic Ewing's sarcoma, but is defined as a distinct entity because of its immunohistological characteristics. The tumor expresses neuronal markers, but the pattern varies: chromogranin, neuron-specific enolase, synaptophysin, protein S-100 and others. MPNT can occur in the urogenital region. The differential diagnosis on clinical grounds must include Ewing's and soft tissue sarcomas, and also Wilms' tumor and its variants. MPNT are often wide spread in the urogenital region when first diagnosed. Response to radiotherapy and combination chemotherapy is limited. Radical surgery is not always possible. The prognosis therefore remains rather poor at this time. A selection of MPNT patients is presented to demonstrate the various problems associated with this diagnosis. MRI and CT of all patients showed large tumors with direct infiltration of the surrounding structures. MRI is the best imaging modality for diagnosis and therapy monitoring in these tumors, because of its high soft-tissue contrast.

A simple exam to screen superficial masses: fine-needle aspiration cytology

Fine-needle aspiration cytology (FNAC) is now considered a useful tool in the evaluation of adult patients with mass lesions. We reviewed the experience with FNAC in our Paediatric Surgical Department. One hundred and eleven FNACs were performed in children with a superficial mass and no definite diagnosis. All the exams were done by the same physician using a fine needle and no anesthesia. We routinely used May-Grüwald-Giemsa and Papanicolaou staining. Patients age ranged from 20 days to 17 years, with a mean age of 6.5 years. A clinically benign pathology was cytologically confirmed in 90 cases (81%). All children did well at follow-up. Malignancy was diagnosed in eight cases (7.2%) and in all was confirmed with a surgical biopsy. In nine children (8.1%) the specimen was considered insufficient for definite diagnosis. In four cases (3.6%) the pathologist diagnosed a possible malignancy that was excluded at surgical biopsy. The sensitivity was 100% and the specificity was 96%. Our experience confirms that FNAC is a fast, cheap, simple, and accurate diagnostic method and should be used for screening in all children with doubtful superficial masses.

Fine-needle aspiration biopsy of childhood rhabdomyosarcoma: reevaluation of the cytologic criteria for diagnosis

The distinction between rhabdomyosarcoma (RMS) and the other small round blue cell tumors of childhood has therapeutic implications which stress the importance of a correct diagnosis. In attempts to reevaluate the cytologic criteria of this entity, we reviewed a series of 17 fine-needle aspiration biopsies and three touch imprints from soft tissue masses. All cases had been histologically confirmed except for two cases that only had immunocytochemical and ultrastructural confirmation. The features occurring most commonly include a uniform population of tumor cells arranged as single cells and cohesive aggregates. The cells were predominantly round/polygonal, with uniform nuclei and scant to moderate amounts of cytoplasm. The nuclear chromatin was most often finely granular and hyperchromatic, while nucleoli were inconspicuous. Binucleated and multinucleated cells were found in 17 of the 20 smears. Intracytoplasmic vacuoles were present in 17 cases, ranging from occasional in one case, a few in 10 cases, and very numerous in six cases. We conclude that the presence of bi/multinucleated cells is an important clue for the diagnosis of RMS on fine-needle aspiration biopsy.

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.

Soft tissue tumours in childhood

The spectrum of soft tissue tumours in young adults is very similar to that in more mature individuals, while those in childhood form a distinct group rarely seen outside the first decade. The majority of these are benign vascular or fibroblastic proliferations; in young children they may be highly cellular and mitotically active, but malignancy should be diagnosed with caution. Congenital soft tissue tumours constitute a special group in which the clinical outcome may be particularly difficult to predict from the histological appearances. This review focuses on those malignant soft tumours which are either peculiar to childhood or which manifest special features in childhood. Some recently recognized benign soft tissue tumours which occur mainly in childhood are also described. The fibromatoses are not discussed. As a guide to the appropriate treatment regime, the main histological distinctions to be drawn are between: 1 tumours of neuroectodermal origin (Ewing's sarcoma and primitive neuroectodermal tumour); 2 other sarcomas; and 3 the fibromatoses and other benign and potentially locally aggressive lesions requiring local excision. Immunohistochemical staining may be of considerable help in achieving the correct diagnosis, but it is vital that a panel of antibodies be applied and the results critically assessed. Cytogenetic analysis is also of growing importance, characteristic karyotypic abnormalities having been demonstrated in Ewing's sarcoma/primitive neuroectodermal tumour, alveolar rhabdomyosarcoma and synovial sarcoma.

Fine-needle aspiration diagnosis of intra-thoracic and intra-abdominal lesions: review of experience in the pediatric age group

Review of fine-needle aspiration (FNA) smears from 121 pediatric patients with intra-thoracic and intra-abdominal lesions revealed 42 (34.7%) cases of neoplasms, 35 (28.9%) cases of tuberculosis, 12 (9.9%) cases of non-tuberculous inflammations, 4 (3.3%) cases of benign cystic lesions, and 28 (23.1%) inadequate/inconclusive cases. The age of the patients ranged from 20 days to 18 yr. Ultrasound and/or CT study done in 105 cases localized the lesions in following common sites: lungs (19 cases), mediastinum (22 cases), liver (14 cases), intestines (11 cases), and lymph nodes (17 cases). The neoplastic lesions consisted of 39 malignant, one suspicious, and two benign neoplasms. Among the neoplasms, the small round cell tumors were the most frequent (27 cases), followed by germ cell tumors (eight cases) and miscellaneous neoplasms (seven cases). The common small round cell tumors were non-Hodgkins lymphoma (eight cases), hepatoblastoma (seven cases), neuroblastoma (five cases), and nephroblastoma (three cases). A combined clinical, imaging, and FNA cytology approach was found to be useful in arriving at a tissue diagnosis.