Cytology of embryonal rhabdomyosarcoma: a cytologic, light microscopic, electron microscopic, and immunohistochemical study of seven cases

A Review of Effusion Cytomorphology of Small Round Cell Tumors

BACKGROUND

Small round cell tumors (SRCTs) are a broad category of diverse malignant tumors composed of monotonous undifferentiated cells. Involvement of serous fluids by SRCT is rare; however, the identification of exfoliated malignant cells is a crucial component of management and has significant implications for treatment and prognosis. The most common effusion tumors with SRCT morphology include Ewing sarcoma, synovial sarcoma, rhabdomyosarcoma (RMS), small-cell neuroendocrine carcinoma (SCNC), and desmoplastic SRCT, and the cytomorphologic distinction between these tumors is challenging. The purpose of this article is to describe the morphologic features of the most common SRCT in fluids and propose helpful ancillary testing.

SUMMARY

Effusion SRCTs display similar primitive and undifferentiated morphologic features although each has subtle variations. Ewing sarcoma is a mesenchymal neoplasm and harbors characteristic translocations t(11;22) (EWSR1-FLI1) or t(21;22) (EWSR1-ERG). In fluids, Ewing sarcoma shows poorly differentiated cells of variable size with round to oval nuclei, prominent nucleoli, and scant cytoplasm. In contrast, synovial sarcoma typically involves extremities and expresses a fusion transcript in t(X;18) (SS18-SSX). This soft tissue neoplasm demonstrates uniform cells with irregular nuclear contours, characteristic nuclear folding, and scant cytoplasm. RMS is a neoplasm arising from skeletal muscle, and the alveolar subtype demonstrates a translocation in t(2;13) (PAX3-FOXO1). The malignant cells show a spectrum of small round cells and pleomorphic large cells with rhabdoid morphology. RMS cells characteristically express myogenin and MyoD1, markers of skeletal muscle differentiation. Although SCNC is not a classic SRCT, the morphology is similar. SCNC demonstrates tight clusters of malignant cells with nuclear molding and salt-and-pepper chromatin. This tumor classically has neuroendocrine differentiation and is positive for synaptophysin and chromogranin on immunohistochemistry. And last, desmoplastic SRCT typically presents as an intra-abdominal mass in young men and characteristically harbors the translocation t(11;22) (p13;q12) (EWSR1-WT1). Cytomorphologically, the tumor shows small monomorphic cells occasionally arranged as rosette-like structures.

KEY MESSAGE

The diagnosis of SRCT can be made in effusion samples and is best achieved with a combination of morphologic features, clinical history, and ancillary testing.

Fine-needle aspiration cytology diagnosis of metastatic nonhaematological neoplasms of the breast: a series of seven cases

Metastatic neoplasms of the breast are rare. Mammary metastases as the initial presentation are even more infrequent and can simulate a primary malignancy clinically and radiologically. Recognition of metastatic tumors in the breast is important because it would prevent unnecessary mutilating surgery and would lead to appropriate treatment of the primary tumor. There is a broad variety of cytological appearances reported about primary tumors and few reports about secondary breast malignancies, specially diagnosed by FNAC. This study was carried out to examine the clinical and cytomorphologic features of metastatic breast tumors found in 12 de Octubre University Hospital during a period of 20 years. It confirms the utility of FNAC and describes findings that can help in the differential diagnosis that sometimes can be very difficult. Seven cases of nonhematological metastatic neoplasms of the breast were identified from the files of the Department of Pathology of the 12 de Octubre University Hospital from a total of 64,000 aspirates. We included only metastatic tumors from extramammary nonhematological neoplasms. There were nine cases of hematological metastatic neoplasm that were excluded. They were diagnosed with FNAC and confirmed by histopathology, with at least three years of follow up. The breast lump was the first manifestation of malignancy in one case of synovial sarcoma. The other six cases had been previously diagnosed of cancer. These included one malignant melanoma, one alveolar rhabdomyosarcoma, one mixed müllerian tumor, one medullary carcinoma of thyroid, one colonic adenocarcinoma, and one gastric adenocarcinoma. The period of time between primary tumor and metastases ranged from one month to eight years. An accurate cytologic diagnosis was made in all the cases. Immunocytochemistry was available but diagnosis could be made with cytomorphology alone in the seven cases. Fine-needle aspiration cytology is an excellent first line diagnostic modality that is particularly informative when clinical previous data are known. If metastatic disease is suspected, the material obtained by FNAC may provide a definitive diagnosis and prevent open surgical biopsy or mastectomy. We concur with previous reports that FNAC is a reliable, rapid, secure, and cost-effective approach to the diagnosis of palpable metastatic breast tumors.

A rare case of paratesticular pleomorphic rhabdomyosarcoma diagnosed by fine needle aspiration: a case report

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of children and young adults. It represents 6.5% of all malignant tumors in pediatrics with an annual incidence of 4 to 7 cases per million children. Embryonal RMS arising in paratesticular region in young males is a common entity, however pleomorphic RMS in such location is quite rare. An eighteen year old male presented with painless right scrotal mass measuring 7 x 6 x 5 cm of two year duration, which was reported on ultrasonography as extratesticular tumor. Fine needle aspiration showed cellular smears comprising of pleomorphic population of mostly singly scattered cells and few cell aggregates. Few isolated large cells with whip like cytoplasmic processes and faint cross-striations were also seen. A diagnosis of paratesticular malignant mesenchymal tumor probably RMS was made. Tumor was removed surgically with right sided orchidectomy. On histopathology, it was reported as pleomorphic RMS. There was focal lymphatic invasion and involvement of rete testis. Immunostaining of tumor cells revealed myogenin and desmin positivity. The case is being presented because of diagnosis of RMS on Fine needle aspiration and rare occurrence of pleomorphic RMS in paratesticular location.

Cyto-histological correlations in primary, recurrent and metastatic rhabdomyosarcoma: the institut Curie's experience

To determine diagnostic cytomorphologic features of rhabdomyosarcoma (RMS) on fine-needle aspiration (FNA) material, the cytologic material and corresponding histologic slides of 180 tumors obtained from 109 patients were reviewed. Fifty eight (32.2%) tumors were primary, 34 (18.9%) recurrent, and 88 (48.9%) metastatic. A review of original cytology reports revealed that 176 of 180 (97.8%) tumors were either diagnosed accurately or as round cell sarcoma, while 3 (1.7%) were reported as suspicious. In one case (0.5%), the material was unsatisfactory. No false negative samples were seen. When FNA morphology was correlated with different histological subtypes, the alveolar subtype RMSs were more cellular than the nonalveolar ones (91.4% vs. 64.9%). Similarly, alveolar subtype RMSs compared with nonalveolar ones exhibited more rhabdomyoblastic cells (77.1% vs. 52.7%), alveolar structures (67.6% vs. 10.8%), giant, multinucleated cells (22.9% vs. 6.7%), mitotic figures (57.1% vs. 18.9%), and cyto-nuclear atypia (77.1% vs. 43.2%). Inversely, spindle-shaped cells were more frequently seen in nonalveolar versus alveolar RMSs (37.8% vs. 20.9%).

Rhabdomyosarcoma in an adult presenting with nodal metastasis: a pitfall in fine-needle aspiration cytology of lymph nodes

A 40-yr-old woman with an asymptomatic sinonasal rhabdomyosarcoma (RMS) initially presented with submental nodal metastasis. The fine-needle aspiration (FNA) and the subsequent biopsy of the nodal metastasis were misinterpreted as metastatic carcinoma because the primary tumor was occult, the tumor cells were exclusively round cells with a nested arrangement, and rhabdomyoblasts were absent. The correct diagnosis of metastatic RMS became apparent when the primary sinonasal tumor, detected in a CT, was biopsy proven to be an alveolar RMS. Retrospectively, there were helpful clues to the correct diagnosis in the nodal FNA and biopsy. When FNA cytology or biopsy histology of a lymph node suggests metastatic carcinoma but the tumor cells are nonimmunoreactive to carcinoma markers, the differential diagnosis should be expanded to include not only metastatic melanoma but also metastatic sarcoma and lymphoma. Cytologically, the presence of multinucleated giant tumor cells, including the rosette forms, in the FNA smears should alert the cytopathologist to the possibilities of sarcoma and anaplastic large cell lymphoma.

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.

Intrarenal neuroblastoma diagnosed by fine-needle aspiration: a report of two cases

Neuroblastoma is an infrequent tumor of childhood usually located at any site containing sympathetic neural tissue-retroperitoneum and adrenal gland being the most common locations, followed by thoracopulmonary region, mediastinum, head and neck, and pelvis. Two primary renal neuroblastomas were diagnosed in a 6-yr-old boy and a 7-mo-old boy by computed tomography (CT)-guided fine-needle aspiration (FNA) cytology. The smears contained numerous individually scattered small and round cells, with scanty cytoplasm, related to a fibrillary matrix. Scattered larger cells with slightly more cytoplasm were seen among the smaller ones. No tubular or glomeruloid differentiation was noted. Considering the age and cytomorphology, a diagnosis of intrarenal neuroblastoma was made in both cases. An intrarenal mass in a child may occasionally be a neuroblastoma. Our cases demonstrate the usefulness of CT-guided FNA in diagnosing intrarenal masses in children.

Topical topic: value of fine needle aspiration biopsy in childhood rhabdomyosarcoma: twenty-six years of experience in Slovenia

BACKGROUND

Chemotherapy (Cht) for rhabdomyosarcoma (RMS) given before local treatment can prevent mutilating surgery and high-dose irradiation (RT). Fine needle aspiration biopsy (FNAB) can confirm the diagnosis and neoadjuvant treatment can start without delay. The purpose of our study was to assess the role of FNAB in the management of childhood RMS in Slovenia.

PROCEDURE

A total of 78 children and young adults were included. FNAB provided the pre-treatment diagnosis in 37 and surgical biopsy in 41 patients. In 61 cases recurrent/metastatic disease was aspirated. Cytological diagnoses were compared to the original histological diagnoses. All case histories, cytological and histological material were reviewed and immunocytochemical staining performed when necessary.

RESULTS

FNAB provided a correct diagnosis of malignancy in all 37 primary tumours, a specific diagnosis of RMS was given in 29 (78%). With the use of immunocytochemistry during the last 15 years, the accuracy has risen to 87%. FNAB provided the diagnosis of recurrence/metastasis in 57/61 cases. No complications of FNAB were noted. Review of histology reclassified five original diagnoses of RMS into one malignant rhabdoid tumour and four sarcomas NOS. In review of cytology we were able to sub classify 80% of RMS.

CONCLUSIONS

FNAB is a safe method, which enables us to establish the pre-treatment diagnosis of RMS, and to some extent even its type, without delay. In our study, FNAB successfully replaced surgical biopsy in 87% of RMS patients during the last 15 years. Neoadjuvant Cht was started immediately, surgery was delayed and more conservative. Consequently, the risk for treatment sequelae was considerably reduced.

The role of fine-needle aspiration biopsy in the diagnosis and management of juvenile hemangioma of the parotid gland and cheek

BACKGROUND

The current recommendation for the management of juvenile hemangiomas (JH) is to delay treatment in the hope of spontaneous regression. However, accurate diagnosis is necessary before considering conservative management. Traditionally, the diagnosis of JH has required excisional biopsy. The cytology literature on this relatively rare neoplasm is sparse.

OBJECTIVE

To present our experience with fine-needle aspiration in the diagnosis and management of JH.

DESIGN

Three cases with a cytologic diagnosis consistent with JH of the parotid gland and cheek were identified from our cytopathology files. Aspirate smears, immunohistochemical studies, computed tomographic scan findings, and clinical follow-up were reviewed.

RESULTS

Patients were female infants ranging in age from 3 to 9 months and presented with an oval firm mass (size range, 2.0-5.0 cm) involving the parotid gland (2 cases) and cheek (1 case). Computed tomographic scan with contrast demonstrated homogeneous enhancement. Aspirate smears revealed spindle-shaped cells in sheets and clusters in a background of blood. The parotid gland aspirates and cell block preparations revealed ductal structures entrapped in sheets of spindle-shaped cells. Immunohistochemical studies revealed prominent vascular spaces lined by CD34 and factor VIII-positive flattened endothelial cells. The diagnosis of JH was rendered on the basis of the cytologic findings in conjunction with the radiologic and clinical findings. On clinical follow-up (8-24 months), none of the patients has shown any progression of the lesion.

CONCLUSIONS

Fine-needle aspiration, in conjunction with imaging studies, is a useful tool in the diagnosis and management of JH. It eliminates the need for surgical excision for diagnostic purposes and allows for clinical follow-up of patients with JH.

PNET-like features of synovial sarcoma of the lung: a pitfall in the cytologic diagnosis of soft-tissue tumors

Fine-needle aspiration (FNA) cytology of soft-tissue tumors is evolving. As more experience is gained, we are becoming aware of potential pitfalls. We describe 2 cases of synovial sarcoma of the lung, primary and metastatic, in patients who had FNA biopsy performed on a lung mass. The cytologic smears showed extremely cellular groups of malignant small round cells, intersected by small blood vessels, with numerous loose single cells, in a background of macrophages and mature lymphocytes. The tumors displayed monomorphic cells forming rosettes and displaying occasional mitoses. A diagnosis of neuroendocrine tumor/primitive neuroepithelial tumor (PNET) was suspected. Furthermore, this suspicion was supported by immunohistochemical stains, which showed positivity for a neuroendocrine marker, Leu 7 (case 1), and for a neural marker, CD 99 (O 13 or HBA 71) (both cases); and negativity for cytokeratins (case 1). The resection specimen of case 1 had mostly tightly packed small round cells, with occasional rosettes, similar to the FNA biopsy, and focal areas composed of spindle cells, organized in a focal fibrosarcoma-like and hemangiopericytoma-like pattern. A balanced translocation between chromosomes X and 18, demonstrated by both karyotyping and fluorescent in situ hybridization (FISH), enabled us to make a diagnosis of synovial sarcoma, which was histologically classified as poorly differentiated. Case 2 was a metastatic biphasic synovial sarcoma of the arm, with a prominent epithelial component. Synovial sarcoma, when composed mainly of small round cells on cytologic smears, is a great mimicker of neuroendocrine/PNET tumors, with light microscopic and immunohistochemical overlap. Awareness of this potential pitfall may aid in preventing a misdiagnosis. Its recognition is of major concern, especially for the poorly differentiated variant, because it is associated with a worse prognosis.

Desmin detection in FNAB samples of rhabdomyosarcoma: an immunocytochemical study

We performed immunocytochemical (ICC) staining for desmin on 65 fine needle aspiration biopsies from 45 patients with rhabdomyosarcoma, using the avidin-biotin-peroxidase complex method (ABC), and two types of antibodies, D33 and DE-R-11. The material was fixed either in ether-alcohol or in Delaunay's solution. The ABC method was applied to Papanicolaou stained slides, without destaining. We compared the quality of staining on fresh, routinely prepared slides vs archival material and the quality of staining on smears vs cytospins. In 20 cases, D33 and DE-R-II were applied to a pair of slides from the same tumour sample in order to see if there was any difference in their ability to recognize desmin. Desmin was positive in all 18 cases in which ICC staining was performed at the same time diagnoses were given. Among the 27 cases where ICC staining was carried out on archival material, seven were negative. Slides from four of these cases were 20 or more years old and negative reaction could be attributed to heating of slides before coversliping and/or to uneven distribution of desmin immunoreactivity in tumours. The second reason was probably the cause of negative reactions in cases from 1985 and 87. The type of slide preparation had no influence on the quality of staining. However, results were easier to read on cytospins because cells were more evenly distributed. Finally, our results proved that there was no significant difference between D33 and DE-R-11 in their ability to recognize desmin.

Fine-needle aspiration biopsy diagnosis of small round cell tumors of childhood: A comprehensive approach

Fine-needle aspiration biopsy findings in small round cell malignant tumors of children are briefly reviewed. All of these tumors usually have characteristic cytomorphology which, when recognized, may lead to a definitive diagnosis. However, when these tumors are undifferentiated, morphologic criteria may not be sufficient for arriving at a correct diagnosis. A variety of ancillary studies including electron microscopy, immunohistochemistry and DNA ploidy, cytogenetics, and fluorescent in situ hybridization may provide valuable additional information for precise characterization of these neoplasms. Some of the ancillary studies may also be used for assigning these cases to prognostically significant subgroups. This information may also help in defining the most suitable chemotherapeutic regimens for these tumors. Since most of these special studies require only a small amount of cellular material, fine-needle aspiration biopsy is ideally suited for obtaining samples for these procedures. It is hoped that as cytogenetic and molecular techniques become available in many diagnostic laboratories, a comprehensive evaluation of aspiration biopsies from round cell malignant tumors, encompassing a precise pathologic diagnosis, determination of prognosis, and prediction of response to therapy, will be possible in a majority of cases. Diagn. Cytopathol. 1999;21:81-91.

Logistic regression analysis of small round cell neoplasms: a cytologic study

The diagnosis of small round cell neoplasms (SRCN) in children is difficult by both histologic and cytologic methods. These neoplasms are unified morphologically by the scanty cytoplasm surrounding relatively round nuclei containing a primitive chromatin pattern. Further categorization is achieved histologically by the recognition of architectural differentiation and cytoplasmic features. Numerous series and case reports documenting the cytologic features of SRCN have been published in the English-language literature, but relatively few studies have statistically analyzed the diagnostic utility of these features. Our logistic regression analysis of 59 cases of SRCN indicates that the presence of an extremely scanty cytoplasm favors the diagnosis of Ewing's sarcoma (P = 0.004), as does the positive expression of cytoplasmic vacuoles (P = 0.02). Strap or tadpole cells closely correlate with the diagnosis of rhabdomyosarcoma (P < 0.001). The positive expression of rosettes strongly supports the presence of a neuroblastoma (P < 0.001). The diagnosis of Wilms' tumor is confirmed by the expression of tubules (P < 0.001). The presence of lymphoglandular bodies strongly favors the diagnosis of lymphoma (P < 0.001). While some cytologic features are highly correlated with specific SRCN, these features are not invariably present, and definitive diagnosis may require immunohistochemical or ultrastructural analysis performed on cell block material.

Cytologic diagnosis and subtyping of rhabdomyosarcoma

We reviewed the cytological findings of 38 cases of rhabdomyosarcoma (RMS) with histological confirmation performed during a period of 15 years and proposed a morphological subtyping based on the most prominent cytologic features. Seventeen of these cases were alveolar, 14 cases embryonal, and seven botryoid subtypes. From these cases, a total of 43 samples, of which 37 were fine needle aspiration (FNA) biopsies and six were touch imprints, were evaluated. Detailed cellular features were identified which enabled differentiation into histological subtypes. In the alveolar RMSs, most tumour cells were small and lymphocyte-like, having finely granular chromatin. The finding of cells with more abundant cytoplasm, eccentrically located nuclei and bi/multinucleated tumour cells in a background of mucosubstance helped in the differential diagnosis. Two cell types, including large, tadpole or ribbon-shaped tumour cells and small, round cells with scant cytoplasm, were seen in embryonal RMSs. In botryoid RMSs, a cell type with tightly grouped nuclei within elongated cytoplasm similar to a myotubular structure was observed in addition to the two cell types of embryonal RMSs. We conclude that with experience it will be possible to subtype these tumours by cytologic examination alone.

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.

Salivary gland anlage tumor: cytologic features in a case examined by fine-needle aspiration

The cytologic features in fine-needle aspirates from a rare benign nasopharyngeal salivary gland anlage tumor in a newborn boy are described and commented on, regarding therapeutically important differential diagnoses.

Juvenile rhabdomyosarcomas in two dogs

Juvenile rhabdomyosarcomas were diagnosed in two young dogs based on the results of histopathology, phosphotungstic acid-hematoxylin stain, immunohistochemistry, and the age of the dogs. One dog, an 11-month-old Rottweiler, had tumor masses in the maxillary gingiva and the urinary bladder. Histologically, the gingival mass was an alveolar type of rhabdomyosarcoma and the urinary bladder mass was an embryonal type. The other dog, a 1.5-year-old Basset Hound, had an embryonal rhabdomyosarcoma involving the oropharynx and the temporal muscles, with metastasis to the regional lymph node and lungs.

Fine needle aspiration (FNA) in the diagnosis of soft tissue tumours; a review of 22 years experience

FNA plays an important role in preoperative diagnosis of soft tissue tumours. A close clinical/morphologic cooperation is essential. FNA should be performed on the most accessible part of the tumour, avoiding penetration of the deep portions of the tumour. Needles 0.7 mm (22 G) are recommended. For deep lesions, needles with a stylet should be used. After the FNA, tattooing of the aspiration channel is recommended, and the channel is surgically removed together with the tumour, if a sarcoma. Material from the FNA can be used for additional examinations, i.e. electron microscopy, immunohistochemistry, DNA ploidy analysis and chromosomal analysis. Those techniques are of great importance in the differential diagnosis, particularly in the paediatric small/round cell tumours. The majority of sarcomas can be defined as low grade or high grade malignant in FNA. For malignancy grading the following parameters are used: cellularity, pleomorphism, chromatin pattern, nucleolar structure, mitotic figures and necroses. Cytodiagnostic details of the most common soft tissue tumours and their differential diagnoses are presented.

Cytopathology of undifferentiated (embryonal) sarcoma of the liver

We have studied one undifferentiated (embryonal) sarcoma of the liver (USL) by fine-needle aspiration cytology (FNAC) and have correlated the cytologic findings with those seen in the histologic sections. The main cytologic and immunocytochemical features were: cellular aspirates, mesenchymal clusters, disparity in individual cell size (small round cells, and multinucleated giant cells, sometimes bizarre), absence of biliary pigment, AFP-negative and vimentin-negative tumor cells, AFP-negative and PAS-positive hyaline globules, and apoptotic cells. Only immunostaining for alpha-1-antitrypsin, alpha-1-antichymotrypsin, and carcinoembryonic antigen were positive in tumor cells in histologic sections. The differential diagnosis should be carried out with rhabdomyosarcomas, hepatoblastomas, malignant fibrous histiocytomas, and poorly differentiated hepatocarcinomas. We think that the cytologic features observed in this case, evaluated both in the appropriate clinical context and in the light of the laboratory findings, may permit the correct diagnosis of this infrequent liver tumor. Nevertheless, more cases need to be studied to assess the reliability of our findings.

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.

Fine-needle aspiration of intra-abdominal desmoplastic small cell tumor

The cytologic features of four cases of histologically confirmed intra-abdominal desmoplastic small cell tumor (DSCT) that occurred in males between 18-27 yr of age are presented. Smears showed small cells with scant cytoplasm which were primarily arranged in loosely cohesive clusters. Nuclei were oval to round with evenly distributed, finely granular chromatin and inconspicuous nucleoli. As is typical of DSCT, the cells strongly expressed keratin and desmin in all cases. In the one case studied by electron microscopy, it was demonstrated that the cells were joined by small junctions and contained paranuclear aggregates of intermediate filaments. The absence of the characteristic desmoplastic stroma in DSCT aspirates and the nonspecific cytologic features of this small round-cell tumor (SRCT) made cytologic interpretation difficult. Cytopathologists should be aware of this entity so that DSCT is included in the differential diagnosis of SRCTs that occur in intra-abdominal sites. A panel of markers that includes keratin and desmin should be used to assist in the identification of DSCT.

Infantile cutaneous rhabdomyosarcoma (Li-Fraumeni syndrome): cytological presentation of fine-needle aspirate biopsy, report of a case

We describe the cytopathological picture of a cutaneous rhabdomyosarcoma located in the left nasal furrow of a 4-mo-old girl, some of whose close relatives have died or suffered from different types of neoplasias (Li-Fraumeni syndrome). We believe that the cytological picture is highly characteristic and rules out other round cell tumours of childhood. We underline the usefulness of FNAC in dermatology and strongly advocate the introduction of this technique into the diagnostic armoury of every dermatologist.

Fine-needle aspiration biopsy diagnosis of rhabdomyosarcoma: cytologic, histologic, and ultrastructural correlations

A series of 15 cases of rhabdomyosarcoma diagnosed by fine-needle aspiration biopsy (FNAB) and confirmed by histopathology is reviewed. Cytologically, the tumors were composed of a variable mixture of cells, which according to the degree of differentiation were categorized as early, intermediate, or late rhabdomyoblasts. Histologically, the tumors were divided into embryonal 9, monomorphic round cell 4, and alveolar rhabdomyosarcoma 2. Comparison of histological and cytological features revealed that embryonal types were composed mainly of early rhabdomyoblasts. Recognition of these patterns may be helpful in FNAB diagnosis of rhabdomyosarcoma.

Fine-needle aspiration biopsy of pediatric neoplasms: correlation between electron microscopy and immunocytochemistry in diagnosis and classification

A series of fine-needle aspiration biopsies performed in 635 children were reviewed. The diagnoses rendered in these patients included malignant lymphoma in 139 (21.9%); Hodgkin's disease, 25 (3.9%); neuroblastoma, 58 (9.1%); Wilms' Tumor, 37 (5.8%); Ewing's sarcoma, 32 (5.0%); rhabdomyosarcoma, 25 (3.9%); retinoblastoma, 22 (3.5%); leukemia infiltrate, 33 (5.2%); and miscellaneous tumors, 52 (8.2%). In 171 patients (26.9%), the biopsy was nondiagnostic. The cytomorphological characteristics of these lesions are briefly described and illustrated. Salient morphological features are further correlated with histological and ultrastructural appearances. Immunocytochemical patterns of these tumors are also discussed briefly.

The cytology of pediatric masses: a differential diagnostic approach

In the United States, fine-needle aspiration biopsy (FNAB) and other cytodiagnostic methods have been underutilized in the evaluation of masses in the pediatric age group. Cytopathologists and cytotechnologists are therefore relatively unfamiliar with the cellular features of lesions that occur in children. On the basis of the cytologic findings from 64 pediatric cases, including 56 FNABs and 8 intra-operative imprints, a differential diagnostic approach to lesions in this age group is presented. The majority of cases can be placed into 1 of 5 cytomorphologic categories: (1) round-cell pattern, (2) mixed inflammatory pattern, (3) spindle-cell pattern, (4) epithelial pattern, and (5) cystic pattern. Once a cytomorphologic category is determined, evaluation for unique cellular features, special studies, and clinical correlation allows a specific diagnosis to be made in most cases. Pitfalls in pediatric cytopathology are illustrated by discussion of the following cases: a renal Burkitt's lymphoma mimicking a Wilms' tumor, a traumatic neuroma masquerading as a recurrent malignant schwannoma, Langerhans-cell histiocytosis resembling granulomatous inflammation, and a cystic granuloma that mimicked a branchial cleft cyst. Consideration of these problems and use of the recommended diagnostic approach will aid in interpretation in this difficult area.

Fine-needle aspiration cytology and the diagnosis of neoplasms in the pediatric age group

Sixty-six aspirates obtained from 63 pediatric patients clinically suspected of having small cell malignancies were studied by a variety of techniques to determine the accuracy and utility of fine-needle aspiration (FNA) in the diagnosis of small round-cell neoplasms (SRCN) of childhood. FNA correctly identified all 47 SRCNs as malignant and gave a correct specific diagnosis in 81% of the cases. No false-positive diagnoses of malignancy occurred in this series. Electron microscopy, immunohistochemistry, and cell culture performed on FNA material were found to be useful aids in the differential diagnosis of these tumors. The cytologic appearances and differential diagnoses of these neoplasms are discussed.

Fine-needle aspiration biopsy diagnosis of pediatric neoplasms

A series of fine-needle aspiration biopsies performed in 635 children were reviewed. The diagnosis rendered in these patients included malignant lymphoma in 139 (21.9%), Hodgkin's disease, 25 (3.9%); neuroblastoma, 58 (9.1%); Wilms' tumor, 37 (5.8%); Ewing's sarcoma, 32 (5.0%); rhabdomyosarcoma, 25 (3.9%); retinoblastoma, 22 (3.5%); leukemia infiltrate, 33 (5.2%); and miscellaneous tumors, 52 (8.2%). In 171 patients (26.9%), the biopsy was nondiagnostic. The cytomorphological characteristics of these lesions are briefly described and illustrated. Salient morphological features are further correlated with histological and ultrastructural appearances.

Rhabdomyosarcomatous differentiation in a neuroblastoma: a potential pitfall in the cytologic diagnosis of small round-cell tumors of childhood

Rhabdomyoblasts demonstrating immunoreactivity for muscle-specific actin, desmin, and myoglobin were identified in smears obtained by aspiration from a large retroperitoneal mass in a 14-mo-old girl. Following a tentative diagnosis of a rhabdomyogenous neoplasm, retroperitoneal exploration and adrenalectomy demonstrated a stromal poor neuroblastoma with extensive rhabdomyogenous differentiation. The presence of a subpopulation of rhabdomyoblasts was not diagnostic of rhabdomyosarcoma when obtained by fine-needle aspiration from a retroperitoneal tumor composed predominantly of primitive small round cells.

Metachronous soft-tissue masses in children and young adults with cancer: correlation of histology and aspiration cytology

We describe a series of 28 fine needle aspiration biopsies (FNAB) of soft tissue from 22 patients. Four patients had two separate FNABs, and one had three aspiration procedures. The patient population was limited to children and young adults (age range, 2 months to 29 years; mean, 16 years) who were known to have diverse forms of cancer, and who subsequently developed a mass in the peripheral soft tissues (including breast). The interval between the time of diagnosis of the primary malignant neoplasm and FNAB ranged from 1 day to 17 years (mean, 39 months). All FNAB diagnoses were confirmed by subsequent surgical open biopsy or clinical follow-up greater than 1 year. No complications occurred from the procedure. The cytomorphology is presented in selected cases and correlated with the patient's original tissue histopathology. Twenty aspirates were diagnosed as cytologically malignant, one as suspicious for malignancy. Seven were considered benign. None were unsatisfactory. One false-positive and no false-negative cytologic diagnoses were obtained. The overall accuracy of FNAB diagnoses was 96%, while sensitivity was 100% and specificity 88%. Sites of aspiration included soft tissues of the head and neck (seven cases), trunk (eight cases), breast (four cases), and extremities (nine cases). Malignant cytologic diagnoses included sarcoma (thirteen), seminoma (two), lymphoma/leukemia (two), melanoma (one), undifferentiated neoplasm (one), and neuroblastoma (one). Electron microscopy of aspirated cells was used to confirm the diagnosis in two cases. Fine needle aspiration biopsy of soft tissue masses from children and young adults with cancer demonstrates a high diagnostic accuracy, and its use is justified in this population.