Fine needle aspiration cytology of primitive neuroectodermal tumors. A report of these cases.

Primitive neuroectodermal tumor (PNET) is a small round cell malignancy arising in soft tissue and bone, predominantly in older children and adolescents. We report the cytomorphologic features and findings of ancillary studies of eight fine needle aspiration (FNA) biopsies from three patients (7-year-old male, 12-year-old female, 9-year-old female). Two of the biopsies suggested the initial diagnosis of PNET of the chest wall, while the remaining six documented recurrent or metastatic disease. In one of these cases the primary diagnosis made by FNA biopsy enabled the pediatric oncologists to give specific therapy for the unresectable tumor and achieve remission. Local recurrences included the chest wall (two cases), pleura (one case) and pericardium (one case), while metastatic disease involved the supraclavicular lymph node and breast. All the cases consisted of small malignant cells with a high nuclear/cytoplasmic ratio and hyperchromatic nuclei without prominent nucleoli. Homer Wright rosettes were seen in only two of the aspirates, and neuropil and ganglion cells were not present. Ancillary studies, including electron microscopy (two cases), immunocytochemistry (four aspirates from two cases) and cytogenetics (11/22 translocation, one case) performed on the aspirated material were aids in making a specific diagnosis and excluded other small round cell tumors of childhood, such as malignant lymphoma, rhabdomyosarcoma and Ewing's sarcoma. The differential diagnosis between PNET and neuroblastoma can be difficult on the basis of an FNA biopsy alone, although light microscopic morphologic differences exist. Clinical features (e.g., age, primary site, metastatic patterns), catecholamine levels, electron microscopy and cytogenetics are necessary in establishing the correct diagnosis.     

Intraabdominal desmoplastic small round cell tumor. Report of a case diagnosed by fine needle aspiration cytology.

In this report, fine needle aspiration (FNA) findings in a case of intraabdominal desmoplastic small round cell tumor (IADSRCT) are presented. Computed tomographic scan-guided FNA performed on a right upper abdominal mass on a 20-year-old man produced a cellular specimen consisting of monomorphic small round cells with scant cytoplasm and ovoid nuclei. FNA cytology and immunocytochemistry suggested the diagnosis of IADSRCT. Surgical removal of the tumor and detailed histology and ultrastructural studies confirmed the cytologic findings.     

Comparative analysis of electron microscopy and immunocytochemistry in the cytologic diagnosis of malignant small round cell tumors

OBJECTIVE: To compare the contributions of electron microscopy (EM) and immunocytochemistry (ICC) as adjuncts in the cytodiagnosis of malignant small round cell tumors (MSRCT). STUDY DESIGN: This prospective study included 57 cases with a preliminary aspiration diagnosis of MSRCT. The contributions of EM and ICC in arriving at a specific diagnosis were evaluated. RESULTS: The 57 cases included 22 cases of Ewing's sarcoma/peripheral neuroectodermal tumor (PNET), 12 neuroblastomas, 8 Wilms' tumors, 6 rhabdomyosarcomas, 5 lymphomas, 2 retinoblastomas and 1 synovial sarcoma. One case remained unclassified. Electron microscopy was crucial to the diagnosis in 38.4% cases as against 39.2% of cases by ICC. The light microscopic diagnosis was confirmed in 42.3% and 53.5% cases by EM and ICC, respectively. EM and ICC were inconclusive for a specific diagnosis in 19.2% and 7.1% of cases, respectively. Technically unsatisfactory preparations in EM and ICC accounted for 5 and 1 cases, respectively. The overall efficiency in making a diagnosis was 80.7% for EM versus 92.8% for ICC. Aberrant expression of antigens led to difficulties in interpretation of ICC, and EM was particularly helpful. The ultrastructural demonstration of neural differentiation in Ewing's sarcoma/PNET tumors helped place tumors in the PNET category. CONCLUSION: While ICC is the ancillary method of choice in the cytologic diagnosis of MSRCT, EM contributes to the diagnosis and improves diagnostic accuracy.     

Retroperitoneal mesenchymal chondrosarcoma. Report of a case diagnosed by fine needle aspiration cytology

An unusual case of retroperitoneal mesenchymal chondrosarcoma diagnosed by fine needle aspiration (FNA) biopsy is described. CT-guided FNA of a mass arising in retroperitoneal soft tissues yielded an amorphous, myxoid material containing two distinct and separate populations of tumor cells. One was an undifferentiated, monomorphic, small cell component with granular cytoplasm and round central nuclei. The second population was an overtly malignant chondroid component scattered within an abundant myxoid matrix showing foamy cytoplasm, marked nuclear pleomorphism and frequent multi-nucleation. These cytologic findings were distinctive and similar to the histologic findings. The differential diagnosis and the possible pitfalls in the FNA diagnosis of this relatively rare tumor are discussed.     

Fine needle aspiration cytology of desmoplastic small round cell tumor. A case report.

BACKGROUND: Intraabdominal desmoplastic small round cell tumor (DSRCT) is a recently recognized type of primitive sarcoma characterized by a predilection for young males, a usually very aggressive course and generally unsuccessful therapy. A primitive histologic appearance with prominent desmoplasia and striking divergent multilineage differentiation are well-described morphologic features of this tumor, along with a consistent fusion of the EWS and WT1 genes at the molecular level. The cytologic literature contains only scattered references to this type of neoplasm. Detailed information on the clinical and fine needle aspiration (FNA) biopsy and the immunocytochemical and ultrastructural findings in a patient with DSRCT is presented. CASE REPORT: A 23-year-old male had a firm abdominal mass with multiple secondary lesions of the liver. An FNA biopsy was performed under ultrasonographic guidance. CONCLUSION: FNA of the liver nodules showed cohesive groups of small cells with hyperchromatic nuclei and inconspicuous nucleoli; immunocytochemically vimentin and desmin showed characteristic perinuclear globular positivity. FNA cytology is an effective means of diagnosing deeply located lesions. The cytologic features of DSRCT need to become familiar to pathologists and must be considered in the differential diagnosis of liver metastasis.     

Malignant teratoma of the thyroid with predominantly neuroepithelial differentiation. Fine needle aspiration cytologic, histologic and immunocytochemical features of a case

BACKGROUND: Teratoma of the thyroid in adults is extremely rare, and most are malignant. Only nine cases have been adequately documented in the English-language literature, and there are no reports detailing the fine needle aspiration (FNA) cytologic characteristics. CASE: A 32-year-old female presented with a left-sided nodular thyroid mass with left cervical lymphadenopathy. FNA cytology of the thyroid and lymph nodes was done. The cytologic and immunocytochemical features were that of a small round cell tumor with neuroepithelial (NE) differentiation, metastasizing to the cervical nodes. Microscopic study of the thyroidectomy specimen showed a tumor showing an NE pattern with occasional islands of squamous and cuboidal epithelium, leading to a diagnosis of malignant teratoma. CONCLUSION: Knowledge of FNA cytologic features of rare but highly malignant lesions like thyroid teratomas allow early recognition so that suitable and possibly aggressive treatment protocols can be adopted in the hope of prolonging survival.     

Cytologic features of metanephric adenoma of the kidney during pregnancy: a case report

BACKGROUND: Metanephric adenoma (MA) is a relatively rare neoplasm derived from metanephric blastema and composed of well-differentiated epithelial nephroblastic cells. In view of its invariably benign clinical outcome, a preoperative diagnosis of this tumor could be of critical importance. Since computed tomography and ultrasound imaging are not per se sufficient to unequivocally distinguish between MA and malignant neoplasms, fine needle aspiration cytology (FNAC) could be the only accurate method to establish a preoperative diagnosis of this tumor. However, cytologic appearance of MA is not well characterized. CASE: A 33-year-old pregnant woman presented with erythrocytosis. Transabdominal ultrasound examination disclosed a mass in her left kidney. FNA smears showed small, uniform cells with bland nuclei arranged in compact acinar and follicular structures; immunocytochemical staining revealed a diffuse, positive reaction for CD57, WT-1 and vimentin, and epithelial membrane antigen and alpha-methylacyl-CoA racemase yielded negative results. These cytologic and immunocytochemicalfindings led to a preoperative diagnosis of MA. After delivery, the diagnosis was confirmed on the surgical specimen. CONCLUSION: A diagnosis of MA could be established by FNAC supported by immunocytochemical analysis. The present case illustrates the clinical impact that this diagnosis could have on patient management.     

Diagnosis of a peripheral neuroectodermal tumour by fine needle aspiration

One case of malignant peripheral neuroectodermal tumour successfully diagnosed by cytology is presented. Although a Papanicolaou stained smear could not lead to a diagnosis more specific than a malignant small cell tumour, ancillary analytic methods performed on the cytologic material including immunocytochemistry and electron microscopy yielded the correct diagnosis of peripheral neuroectodermal tumour. This case demonstrates that a precise categorization of small round cell tumours may be achieved by cytology as long as some material is kept for immunocytochemical and ultrastructural studies.     

Fine needle aspiration cytology of perineurioma. Report of a case with histologic, immunohistochemical and ultrastructural studies

The fine needle aspiration (FNA) findings are presented for a case of perineurioma, a benign soft tissue tumor composed of perineurial cells, which are epithelial-like and ensheath the endoneurial connective tissue space of nerve fibers. A subcutaneous FNA performed on a posterior thigh mass of a 14-month-old boy produced a specimen consisting of numerous spindle-shaped tumor cells with bipolar cytoplasmic extensions and occasional pseudosignet-ring cells in a prominent myxoid background. Cytologically, a diagnosis of benign myxoid tumor was made. Histologic examination of the resected tumor revealed the characteristic features that have been described for perineurioma; the diagnosis was confirmed with immunocytochemical and ultrastructural studies. Perneurioma should be included in the differential diagnosis of benign myxoid neoplasms seen in FNA biopsy specimens.     

Masson's vegetant intravascular hemangioendothelioma. Fine needle aspiration cytology, histology and immunohistochemistry of a case

Masson's vegetant hemangioendothelioma is a benign intravascular tumor, sometimes confused with such malignant vascular tumors as angiosarcoma, whose clinical appearance is nonspecific and whose diagnosis can only be established through microscopic examination. The fine needle aspiration (FNA) cytologic findings together with the histologic and immunohistochemical findings of such a tumor in a 22-year-old man are presented. Cytologically, the material obtained by FNA consisted of two distinct populations of cells. One type of cell had large nuclei (sometimes displaced towards the periphery), finely granular chromatin, prominent nucleoli and abundant globular cytoplasm. The second type of cell had spindle-shaped or oval nuclei, granular chromatin and scanty eosinophilic cytoplasm. Although these findings may permit the cytologic recognition of this entity, the aspirate in this case was interpreted as showing a vascular mesenchymal tumor of probable malignancy. Histologic examination of the excised tumor, aided by immunoperoxidase studies for factor VIII antigen that revealed the endothelial nature of the proliferating cells, established the correct diagnosis.     

Parotid metastasis of Merkel cell carcinoma in a young patient with ectodermal dysplasia. Diagnosis by fine needle aspiration cytology and immunocytochemistry.

Fine needle aspiration (FNA) biopsy was performed on an intraparotid lymph node metastasis of a Merkel cell carcinoma of the eyelid in a 15-year-old girl with antecedent ectodermal dysplasia syndrome. The cytologic appearance of the aspirate and the results of immunocytochemical typing of intermediate filaments on the FNA smears provided a definitive diagnosis. The Romanowsky stain provided an excellent delineation of paranuclear intracytoplasmic "buttons," which appeared to contain both cytokeratin and neurofilaments by immunocytochemical studies. These findings confirm previous data emphasizing the role of light microscopic observations, supplemented by proper immunocytochemical investigations, in the differential diagnosis of metastatic Merkel cell carcinoma in fine needle aspirates.     

Fine needle aspiration cytology of metastatic malignant schwannoma. A case report

A metastatic malignant schwannoma diagnosed by fine needle aspiration (FNA) biopsy in a 56-year-old man is reported. Cytologic examination of smears and cell blocks prepared from aspirates of a vertebral mass suggested the presence of metastases from a previously excised malignant schwannoma on the right leg. Electron microscopic and immunocytochemical studies on the aspirate supported the diagnosis, as did the patient's clinical history and previous pathology and the radiographic demonstration of metastatic lesions in the lung. The cytologic findings (cells with oval-to-spindled nuclei and ill-defined cellular borders suspended within a delicately fibrillar eosinophilic matrix) are discussed in light of the histologic diversity of this lesion and the problems of distinguishing it from other sarcomas. The ability to diagnose metastatic malignant schwannoma by FNA emphasizes the value of this technique.     

Fine needle aspiration cytology of pancreatoblastoma with immunocytochemical and ultrastructural studies

The cytologic features of a pancreatoblastoma (infantile adenocarcinoma), a rare pancreatic neoplasm of childhood, are described. Fine needle aspiration (FNA) under ultrasound guidance produced a hypercellular specimen consisting of numerous oval-to-cuboidal cells that had a moderate amount of granular cytoplasm. Spindle-shaped, elongated and triangular-shaped epithelial cells were also seen, along with smaller cells that had a higher nuclear/cytoplasmic ratio and a denser cytoplasm. In addition, there were abundant fragments of stroma present, including some surrounded by epithelial cells. Immunoperoxidase studies performed on the aspirated material revealed positive staining of the epithelial cells for cytokeratin (AE1/3), including high and low molecular weight cytokeratin, carcinoembryonic antigen, neuron-specific enolase and alpha-1-antitrypsin. Ultrastructural examination demonstrated epithelial cells containing either large electron-dense zymogen granules in the range of 400 nm to 600 nm or small dense neuroendocrine granules measuring from 100 nm to 200 nm. This finding, in concert with the immunocytochemical studies, supported a "blastemal" cell origin with bidirectional differentiation for this unusual pancreatic neoplasm and enabled a specific preoperative diagnosis of pancreatoblastoma to be made. The differential diagnosis of pancreatoblastoma from other pediatric neoplasms involving the pancreas, including neuroendocrine tumors and neoplasms of acinar cell derivation, is presented. We believe that the FNA cytologic findings can lead to a correct diagnosis of pancreatoblastoma, especially when coupled with immunocytochemical and ultrastructural studies performed on the aspirated material.     

Fine needle aspiration of pediatric abdominal masses. Cytologic and electron microscopic diagnosis.

Fine needle aspiration (FNA) was performed under ultrasound guidance on 17 abdominal masses in 16 pediatric patients at Baragwanath Hospital. The aspirated cellular material was assessed by conventional cytomorphology and by electron microscopy (EM). A diagnosis of malignancy was rendered for all 15 tumors that were adequately sampled (88.2%); the remaining 2 masses yielded insufficient material for either light microscopy or EM. Cytologic cell typing (including the use of EM) was successful in 12 of the 15 tumors (80%) as compared with the histologic diagnosis. EM was in agreement with the initial cytologic diagnosis in eight tumors, but corrected the initial impression in four tumors. The tumors with adequate aspirates included nine nephroblastomas and single examples of neuroblastoma, hepatoblastoma, non-Hodgkin's lymphoma, rhabdomyosarcoma, renal carcinoma and malignant rhabdoid tumor. The last three were not accurately typed by cytology plus EM. These preliminary results suggest that FNA cytology with adjunctive EM could become a useful technique in the preoperative assessment of pediatric abdominal tumors.     

Malignant fibrous histiocytoma of the chest wall masquerading as medullary breast carcinoma: a case report

BACKGROUND: Cytologic diagnosis of malignant fibrous histiocytoma can be problematic, as these neoplasms are known to mimic multiple other conditions. CASE: A fine needle aspirate from a 60-year-old woman was diagnosed at 2 institutions as medullary carcinoma of the breast. The patient received neo-adjuvant chemoradiotherapy before the tumor war excised. Gross pathologic examination and histomorphology on routine staining were compatible with the cytologic diagnosis. The accurate diagnosis of pleomorphic-storiform-type malignant fibrous histiocytoma was a surprise and was established with immunocytochemical stains. In retrospect, it was thought that clinical and radiologic overlap, creating a high index of suspicion for a breast neoplasm and compounding the cytologic appearance of a medullary carcinoma with spindle cell metaplasia and syncytial cells, was responsible for the error. CONCLUSION: This case highlights a potential cytodiagnostic pitfall and the importance of establishing a definitive tissue diagnosis in the face of equivocal cytologic findings.     

Primitive neuroectodermal tumor of the uterus. A case report

BACKGROUND: Primitive neuroectodermal tumor (PNET) is a rare tumor derived from fetal neuroectodermal cells. These tumors occur in the central nervous system and in peripheral locations. Histologic diagnosis is the standard since most of these tumors are detected at an advanced stage. CASE: A 17-year-old female presented with persistent vaginal bleeding. Physical examination revealed a 4-cm, hard, barrel-shaped cervix. A cervicovaginal smear was obtained. The specimen was hypercellular, with small to medium-sized, round, malignant cells. A diagnosis of PNET was made from the histologic sections of the surgical specimen. CONCLUSION: When numerous small round cells in a diffuse pattern are seen on a Pap smear, the differential diagnosis is long and difficult. However, with careful evaluation of the cytologic features, a few reasonable differential diagnoses can be reached. Furthermore, with liquid-based Pap smears, material is available for immunohistochemical staining to narrow the range even more. Using all resources, including a good clinical history, a cytopathologist can give the clinician an early diagnosis for intervention and treatment.     

Fine needle aspiration cytology, immunocytochemistry and electron microscopy in a rare case of carcinoma of the breast with malignant epithelial giant cells

The cytohistologic findings in a fine needle aspirate from a case of the rare breast carcinoma with bizarre tumor giant cells are described, along with the results of immunocytochemical and ultrastructural studies. The observations in this case suggest that the bizarre malignant giant cells in this type of breast cancer are of an epithelial origin, rather than a histiocytic-stromal origin. The other conditions that may yield giant cells in needle aspirates of breast masses are briefly discussed.     

Myoepithelioma of the parotid gland initially diagnosed by fine needle aspiration cytology and immunocytochemistry: a case report

BACKGROUND: Myoepithelioma is a rare, benign tumor of the salivary gland, most commonly affecting the parotid gland. Although the cytologic features of myoepithelioma are documented in a few case reports, it has rarely been diagnosed preoperatively by fine needle aspiration (FNA) cytology. CASE: A 33-year-old man presented with a left parotid swelling 2.5 cm in diameter and of about 5 years' duration. FNA smears showed bundles of spindle-shaped cells as well as plasmacytoid and stellate cells in sheets and dissociated forms. A few cells had nuclear grooves, and occasional cells showed intranuclear cytoplasmic inclusions. In May-Grünwald-Giemsa-stained smears, most of the cells had reddish cytoplasm. Red to purple, myxoid matrix was present as a scanty fibrillar substance and as globules surrounded by tumor cells vaguely reminiscent of adenoid cystic carcinoma. A cytodiagnosis of myoepithelioma was given and corroborated by immunocytochemical staining, which revealed a positive reaction for vimentin, smooth muscle actin and S-100 protein. Epithelial membrane antigen yielded a negative reaction except for a few plasmacytoid cells with weakly positive staining. Histopathology of the resected tumor and immunohistochemical staining confirmed the cytodiagnosis of myoepithelioma. CONCLUSION: FNA cytologic features together with immunocytochemical studies on smears can offer a preoperative diagnosis of myoepithelioma.     

Fine needle aspiration cytology of a rhabdomyoma of the pharynx

The fine needle aspiration (FNA) cytology of an extracardiac adult rhabdomyoma of the pharynx is documented. The smear of the aspirate contained large cells with peripherally located, uniform, round nuclei and abundant granular eosinophilic cytoplasm. In addition to these features, peripheral vacuoles were seen in sections of a cell block prepared from the aspirate. Special stains of the cell block sections and of the surgical specimen showed cross striations in some cells while electron microscopy showed the typical features of adult rhabdomyoma. The findings in this case suggest that FNA can diagnose this rare, benign neoplasm when it presents as a solitary mass in the head and neck region. Its differential diagnosis from other neoplasms that occur in that area is discussed.