Cytologic features of meningioma: An analysis of common and uncommon subtypes and diagnostic difficulties during intraoperative procedures

Despite common histogenesis meningiomas have a wide morphologic spectrum, and the World Health Organization (WHO) recognizes 15 subtypes. They are the most common brain tumour in adults and typically have an extra-axial location. Although there have been important advances in the molecular biology of meningiomas its diagnosis is based on histopathologic features. The great majority are benign WHO grade 1 tumours. There are specific criteria for assigning WHO grade 2 and 3 that can be applied to all meningioma subtypes. Regardless of these criteria, chordoid and clear cell morphologic subtypes are considered grade 2. WHO grade 3 tumours exhibit a very high mitotic index, frank anaplasia or specific molecular abnormalities. The impressive morphologic diversity shown by meningiomas makes them a diagnostic challenge, which can be even greater in intraoperative studies. The focus of this article is to describe and illustrate their main cytologic features, with emphasis on the most infrequent subtypes.

A comprehensive review of the "tigroid" background cytological concept: what, when, where and why?

The concept of “tigroid” background is used in cytology to describe a peculiar smear background characterized by the presence of a relatively granular, reticulated material that was described as “foamy, lazy, tiger-striped or astrakhan”. It was used to describe the background seen in smears obtained from seminoma. In addition to seminoma, we now know that it can be present in different tumours, mostly carcinomas and round cell sarcomas. These share with seminoma a cytoplasm with high glycogen content and many times clear cell morphology. The “tigroid” background is seen when smears are air-dried and Romanowsky-based stains are used (May-Grunwald-Giemsa and Diff-Quik stains). It is only seen in fine needle aspiration or intraoperative squashing or scrapping samples, but not in specimens obtained from effusions or liquid-based cytology. Wet-fixed cytologic samples with alcohol or with formaldehyde tend to dissolve the background so it is not usually present in Papanicolaou stained smears. In this review, we discuss tumours in which the “tigroid” background is observed and its potential diagnostic utility and aetiology. It is interesting to remark that except for parathyroid adenoma and adenomatoid tumour all the neoplasms in which this background has been observed are malignant.

Fine needle aspiration cytology of polymorphous adenocarcinoma of the salivary glands: A report of 11 patients and review of the literature

BACKGROUND

Polymorphous adenocarcinoma (PAC) is a rare malignant tumor of the minor salivary glands. It has an infiltrative growth, variable architectural patterns, neurotropism and cellular monomorphism. Approximately 75% of the cases show a specific mutation in the protein kinase D1 (PRKD1) gene. Reflecting the rarity of the tumor and intraoral location, the cytologic experience is limited with few reported series. In this study we analyze our cytologic experience to determine if a preoperative diagnosis is possible.

METHODS

A retrospective study of 11 patients with PAC in which a cytologic study was available. A review of the literature was also performed.

RESULTS

Our study shows that PAC has relatively constant cytological features. The analysis of the cytological literature although it shows some heterogeneity, also reveals repetitive cytological findings. Smears are cellular with irregular groups some showing pseudopapillary branching morphology. Monolayered clusters and small acinar structures are also present. Most cases have small metachromatic globules embedded within the groups determining a cylindromatous pattern. Tumoral cells are small and uniform with scarce to moderate cytoplasm. Nuclei are round and oval with occasional grooves and small nucleoli.

CONCLUSION

PAC has characteristic cytological features that together with its location in minor salivary gland must make us consider it preoperatively. It may resemble basal cell adenoma and epithelial-rich pleomorphic adenoma so we should be cautious in the final diagnosis. Whenever possible, the characteristic cytomorphology of PCA should make us evaluate the mutational status of PRKD1 gene since it may permit a more accurate diagnosis.

FNA cytology of postoperative pseudotumoral lesions induced by oxidized cellulose hemostatic agents

BACKGROUND

The use of topically applied hemostatic substances during surgery has become a common practice. In some cases, the material is not absorbed or induces a granulomatous reaction resulting in a pseudotumoral lesion. With imaging studies, it is not possible to differentiate this from a tumor recurrence or abscess. This study describes the authors' cytologic experience with a large series of pseudotumoral lesions induced by oxidized cellulose, one of the most commonly used hemostatic agents. Almost no cytologic descriptions are available in the medical literature.

METHODS

Sixteen patients were evaluated, and the most common sites of fine-needle aspiration (FNA) were the mediastinum and thyroid surgical bed. Other locations were the axilla, neck, vulva, liver, and retroperitoneum. All these lesions appeared after surgical procedures in which oxidized cellulose was used as a topical hemostatic agent. The interval time between surgery and FNA varied from 4 to 46 months with a mean of 15 months.

RESULTS

Cytology samples showed very similar findings. In all cases, foreign-body material with a variable granulomatous reaction was present. Oxidized cellulose was seen as laminated inorganic fragments and most often showed an elongated, quadrangular appearance. Amorphous, ill-defined fragments as well as a dense proteinaceous background with phagocytic cells were also present.

CONCLUSIONS

The current study demonstrates that FNA cytology is a very useful method for the detection of pseudotumoral lesions induced by hemostatic agents. Pathologists must be familiarized with this finding because cytology permits easy differentiation from tumor recurrence.

Micropapillary carcinoma of the urinary tract: a cytologic study of urine and fine-needle aspirate samples

OBJECTIVE

Micropapillary carcinoma (MPC) is an aggressive variant of urothelial carcinoma that needs early and specific recognition. In order to determine whether this tumor variant can be recognized with cytology, we evaluated a large cytohistological series.

STUDY DESIGN

It was a retrospective cytohistological correlation study including 20 patients with MPC. Only those cases in which the tumor exhibited >50% of micropapillary growth were selected. Twenty exfoliative urine specimens and four needle aspirates from lymph node metastases were reviewed.

RESULTS

On histology, 14 cases were infiltrative, while 6 were exclusively superficial. Cytology was characterized by numerous small, cohesive groups and single neoplastic cells. Pseudopapillae were present in 17 cases and in 9 they were a relevant finding. Morules were present in 15 cases. Isolated microacini were seen in 14 cases. Infiltrative tumors showed more neoplastic groups. Cellular atypia was prominent in 17 cases. In 15 cases, a cytologic diagnosis of urothelial carcinoma was made. One case was diagnosed as adenocarcinoma. The remaining 4 cases were considered suspicious of malignancy.

CONCLUSIONS

The peculiar morphology of MPC of the urinary tract is partially reflected on cytology, allowing in some cases a specific recognition. This is important since the aggressive behavior of this neoplasm needs rapid management and treatment.

Fine needle aspiration cytology of basal cell adenoma of the salivary gland: a cytohistological correlation study of 35 cases

OBJECTIVE

In order to evaluate the possibility of a specific cytological recognition of basal cell adenoma (BCA) we reviewed our experience with 35 histologically proven cases. Few series describing cytological features of BCA are available and diagnostic cytological criteria are not well established.

METHODS

This study was based on 41 cytology samples from 35 patients with BCA. Thirty-five aspiration procedures were performed pre-operatively and six on tumour recurrence. Nineteen of the 35 patients were men and 16 women. The mean age at diagnosis was 55 years old (range 24-92). The series includes one non-representative case. Except for one tumour located in the upper lip, all of them involved the parotid gland.

RESULTS

Aspirates were cellular, showing groups with dense, homogeneous metachromatic stroma and single cells. Relevant features were the trident-like configuration of groups, intimate relationship between neoplastic cells and stroma and cellular polymorphism. In approximately half of the cases a precise diagnosis was given. Most of the remaining tumours were diagnosed as benign but they were difficult to differentiate from pleomorphic adenoma. Regarding malignancy, there were two misdiagnoses of acinic cell carcinoma, due to high epithelial cellularity along with scarcity of stroma, and one case was considered to be suspicious of malignancy.

CONCLUSION

BCA shows characteristic cytological features that allow a precise diagnosis. The main differential diagnosis is epithelial-rich pleomorphic adenoma, while acinic cell carcinoma is a potential false positive.

Role of fine needle aspiration cytology in the diagnosis and management of Warthin's tumour of the salivary glands

OBJECTIVE

Local excision surgical procedures and non-surgical conservative management are considered alternatives to superficial parotidectomy in the treatment and management of Warthin's tumour (WT). Such therapeutic alternatives demand accurate diagnosis. In order to determine whether fine needle aspiration cytology (FNAC) is capable of rendering such a minimally invasive diagnosis, we evaluated its accuracy and diagnostic parameters in a large series of histologically proven cases of WT.

METHODS

A cytohistological study of 116 salivary tumours from 110 patients (four WT were bilateral) with a histological or cytological diagnosis of WT.

RESULTS

Histology confirmed the cytological diagnosis in 103 of 114 tumours (90.4%). Two tumours were incorrectly diagnosed on cytology as WT. In 11 cases of WT there was an erroneous or non-representative cytological diagnosis. The sensitivity was 90.4%, and positive predictive value 98.1%. Regarding malignancy, there were three misdiagnoses. One tumour diagnosed as WT was a low-grade mucoepidermoid carcinoma. Two cases considered 'suspicious of squamous cell carcinoma' corresponded to WT. After review, 81.3% of the cases of WT were considered typical and 18.7% non-typical; all misdiagnoses were in the latter group. Cytological difficulties could be divided into three areas: (i) absence of one or more diagnostic components; (ii) 'squamoid' pattern; and (iii) mucinous metaplasia. Degenerated oncocytes were present in 65% of cases.

CONCLUSIONS

FNAC offers the possibility of a reliable diagnosis of WT. Pathologists must pay attention to the squamous appearance of degenerated oncocytes. Cytology, when coupled with clinical and image findings, may permit conservative tumour management.

Cytologic diagnostic accuracy in pleomorphic adenoma of the salivary glands during 2 periods. A comparative analysis

OBJECTIVE

To determine if previous experience with the cytologic presentation of pleomorphic adenoma (PA) results in a lower number of diagnostic errors.

STUDY DESIGN

Comparative analysis of the diagnostic accuracy of PA during 2 periods (1980-1994 and 1995-2003). The first period included 198 tumors and the second, 230. Diagnostic errors were divided into major or minor according to the consequences for patient management. Major errors were considered those that could result in an erroneous surgical approach or treatment delay.

RESULTS

Concordant results increased from 88.4% to 91.2%. Sensitivity rose from 92.6% to 95.5%. The false negative rate diminished from 7.1% to 4.5%. Regarding malignancy, false negative diagnoses diminished from 5 to 3. The second period included no false positive diagnoses of malignancy, while the first had 3. A total of 42 errors were present, 6 of them were nonrepresentative cases. Thirteen of the remaining 36 (36.1%) were considered major errors, while 23 (63.9%) were classified as minor errors. Major errors diminished from 8 to 5. The most significant reduction in errors occurred in the category of PA showing cystic transformation.

CONCLUSION

Cytologic diagnostic accuracy of PA is high, and major errors may diminish if special attention is paid to some pitfalls. Sampling limitations and interpretive difficulties may prevent differentiation from afew cases of carcinoma ex-PA and adenoid cystic carcinoma (ACC). A few diagnostic errors are difficult to avoid. Small tissue biopsies will not resolve these problems.

Cytologic features of pheochromocytoma and retroperitoneal paraganglioma: a morphologic and immunohistochemical study of 13 cases

OBJECTIVE

To review the cytologic features and potential pitfalls of pheochromocytoma and retroperitoneal paraganglioma and to evaluate complications of the aspiration procedure and the diagnostic utility of immunocytochemistry.

STUDY DESIGN

We reviewed 15 cytologic specimens from 12 patients with 13 tumors (1 bilateral case). Ten were adrenal (pheochromocytomas) and 3 extraadrenal paragangliomas. Eleven specimens were from fine needle aspiration (FNA) procedures that were performed in collaboration with radiologists using 23-25-gauge needles. In 3 patients the cytologic material was obtained during intraoperative diagnosis. Immunocytochemistry was performed on alcohol-fixed smears.

RESULTS

Two aspirates were hypocellular, while the remainder were cellular. Cells were distributed singly or formed discohesive groups. When present, cytoplasm was abundant and ill defined. Most cells had an eccentric nucleus and plasmacytoid morphology. Nuclear pleomorphism, binucleation and multinucletaion, naked nuclei and intranuclear preudoinclusions were common findings. In 2 cases a lipid background was seen focally. Evident cytoplasmic immunoexpression of synaptophysin or chromogranin was detected in the 10 cases analyzed. One patient developed a hypertensive episode during the FNA procedure. It was controlled medically without complications.

CONCLUSION

When adequate cytologic material is present, the recognition of pheochromocytoma and extraadrenal paraganglioma is possible. Together with morphology, immunocytochemical studies allow a specific preoperative diagnosis. Scarce material can be a source of diagnostic errors. FNA of pheochromocytomas is not necessarily contraindicated. When analytic data are not diagnostic, FNA may follow. Aspiration must be performed in an area equipped with the therapeutic tools necessary to control a pheochromocytoma crisis.

Fine needle aspiration cytology of dedifferentiated acinic cell carcinoma of the parotid gland: a case report

BACKGROUND

Dedifferentiation of acinic cell carcinoma (ACC) to undifferentiated carcinoma occurs rarely and entails a poor prognosis. Most cases of dedifferentiation occur as recurrences of a previously excised ACC. More rarely the neoplasm presents with areas of well-differentiated ACC coexisting with dedifferentiated ones.

CASE

An 85-year-old man presented with 2 nodular areas in the right parotid area. Fine needle aspiration of both nodules was performed. In both cases cytology revealed a double epithelial component in similar proportions. The first one corresponded to cohesive groups of small to intermediate-sized, polygonal cells with round, monomorphic nuclei. They were distributed in small and larger, branching groups with acinic morphology. Intermixed with this population, irregular groups of larger, pleomorphic cells with irregular nuclei, prominent nucleoli and scarce cytoplasm were present. In addition, smears showed an abundant lymphoid background. A cytologic diagnosis of "salivary carcinoma with coexisting areas of acinic cell differentiation and high grade, undifferentiated carcinoma" was given. Histopathology revealed a well-differentiated ACC with areas of high grade undifferentiated carcinoma (dedifferentiated ACC).

CONCLUSION

The current case expands the cytomorphologic spectrum of ACC. Cytology may permit the preoperative recognition of dedifferentiation, allowing a more sound therapeutic approach.

Large cell neuroendocrine carcinoma of the parotid gland: case report and literature review

A 74-year-old male presented with a large polinodular mass in the neck. Fine needle aspiration cytology (FNAC) showed an undifferentiated large cell carcinoma. Computed tomography (CT) showed a large parotid mass with multiple satelite nodules. The remaining radiological studies were normal. Radical parotidectomy was performed. The tumor was a large cell carcinoma with neuroendocrine features and positive immunostain for neuroendocrine markers. The patient received postoperative radiotherapy and was free of tumor eight months later. Only four cases of large cell neuroendocrine carcinoma (LCNEC) of the salivary gland have been communicated. All of them have involved the parotid gland. This tumor presents in elderly patients as a large infiltrating parotid mass. Fine needle aspiration cytology serves to recognize the carcinoma, but it fails in recognizing the neuroendocrine features of the tumor. The histopathological features of this tumor are the same as in other organs. Chromogranin and synaptophysin are useful immunohistochemical markers. A primary location of the tumor in another organ, specially the lung, should be ruled out. Surgery is the main treatment modality and can be complemented with postoperative radiotherapy. The prognosis seems to be poor. More studies are needed to better define the therapeutical alternatives and prognostic factors of these rare tumors.

Fine needle aspiration cytology of mammary carcinoma with osteoclast-like giant cells

Carcinoma with osteoclast-like giant cells (OCGC) is an uncommon neoplasm characterized by giant cells, prominent vascularization, haemorrhage and areas of cribriform epithelial growth with moderate atypia. Multinucleated giant cells (MGC) have been described in several other breast lesions raising an interesting differential diagnosis, mainly with benign disorders. Due to its rarity few cases have been described cytologically. We retrospectively reviewed 13 fine needle aspiration samples from nine patients with this variant of carcinoma. Nine corresponded to breast tumours and four to axillary, liver, subcutaneous and mediastinal metastatic lesions. The expression of CD68 by giant cells was evaluated immunocytochemically in six cases. All patients had a complete pathological study of the breast neoplasm. Smears showed a double component of epithelial and giant cells. Epithelial clusters were predominantly of intermediate size with irregular contours. Most were cohesive but others showed cellular dissociation with scarce to moderate cellular pleomorphism. Giant cells had well defined, deeply stained cytoplasm and round to elongated morphology. Two metastatic cases were devoid of them. Haemosiderin-laden macrophages were common in smears from breast tumours. In the six cases tested CD68 was expressed in MGC. Cytological features of mammary carcinoma with OCGC correlate closely with the histological ones. Most cases are clearly recognizable as malignant but in others cytological atypia may be minimal, mimicking a benign lesion. In difficult cases the presence of haemosiderin-laden macrophages and the histiocytic nature of the MGC are helpful diagnostic features.

Fine-needle aspiration cytology of metastatic nasopharyngeal carcinoma

Cytological features of nasopharyngeal carcinoma (NPC) were reviewed in an attempt to select cytological criteria that permit a specific recognition of metastases. For this purpose, 54 fine-needle aspiration (FNA) procedures from 43 patients with NPC were analyzed. Thirty-two (59.3%) procedures were performed before the histological diagnosis. In 25 (46.3%) procedures, smears showed many neoplastic single cells, clusters, and abundant lymphoid cells (mixed pattern). A dissociated (single cell) pattern consisting of individual neoplastic and lymphoid cells was seen in 18 (33.3%) cases. Finally, 11 (20.4%) cases showed cohesive epithelial clusters (cohesive pattern) without relevant cellular dissociation or lymphoid cells. Squamous-cell differentiation was seen in three of these cases. Most single neoplastic cells presented as large, pleomorphic naked nuclei. Other interesting findings were granulomas (n = 3), prominent eosinophilic infiltrates (n = 4), and suppurative changes (n = 5). In most smears with mixed and dissociated patterns, a nasopharyngeal origin could be suggested. On the contrary, those smears with a cohesive pattern were indistinguishable from other head and neck carcinomas. The presence (on cervical lymph nodes) of a dissociated or mixed (single cells and groups) architectural pattern of large, anaplastic cells and naked nuclei accompanied by an abundant lymphoid component is highly suggestive of undifferentiated NPC. Cytology offers a rapid diagnosis, establishes the necessity of a complete cavum examination, and helps in avoiding unnecessary and harmful biopsies.

Fine needle aspiration of toxoplasmic (Piringer-Kuchinka) lymphadenitis: a cytohistologic correlation study

OBJECTIVE

To define the cytomorphologic features of toxoplasmic lymphadenitis (TL) and to establish the diagnostic sensitivity and specificity of the cytologic diagnosis.

STUDY DESIGN

A cytohistologic correlation study of 11 patients in which a histologic diagnosis of TL was available. These cases were analyzed in a blind study among other cases of nonneoplastic lymphadenopathies. The results of the study are expressed in terms of diagnostic sensitivity and specificity. Although not included in the study, 3 other cases of TL with serologic confirmation were also reviewed.

RESULTS

Microgranulomas were a characteristic finding in TL. They consisted of small clusters of epithelioid histiocytes, each with abundant cytoplasm and an eccentric, oval nucleus. Diff-Quik-stained smears had cytoplasm with particularly pale staining and a homogeneous appearance. Most microgranulomas had a monotonous appearance with a few, small lymphocytes accompanying the epithelioid cells. No necrosis, suppurative changes or giant cells were present. Blind examination by 4 reviewers led to a correct diagnosis of TL in 9 of the 11 cases. Eight of the 9 cases were recognized by each of the 4 reviewers. One false positive diagnosis was made by 1 of the reviewers. The sensitivity of the diagnosis was 72.7-81.8% and the specificity 98.8-100%.

CONCLUSION

This study showed high sensitivity and specificity for the cytologic diagnosis of TL. Given the appropriate clinical context, the presence of characteristic epithelioid microgranulomas permits a diagnosis of TL. The cytologic diagnosis can be easily confirmed with serologic studies, thereby avoiding biopsy.

Fine-needle aspiration cytology of lipoblastoma: A report of two cases

Lipoblastoma is an uncommon lipomatous tumor that typically occurs in infants and children. It may present as a single subcutaneous nodule or with multiple lesions (lipoblastomatosis). We describe fine-needle aspiration (FNA) cytologic features of two cases that presented as a subcutaneous lump in the scapular area and as a deeply located mass in the left arm. Smears showed fragments of adipose tissue that consisted of numerous vacuolated adipocytes with few stroma. Nuclei were small and located centrically, without indentations. Myxoid stromal material was a remarkable finding in one case. Both cases showed small delicate vessels, mainly in relation with the myxoid material. No necrosis, atypia, or mitotic figures were present. Cytologic features were characteristic enough to permit a specific diagnosis (adipose tumor suggestive of lipoblastoma). The differential diagnosis should consider lipoma with regressive changes, well-differentiated and mixoid liposarcoma. In addition to cytologic features, the patient's age is very useful for differentiation.

Fine needle aspiration cytology of endocrine neoplasms of the pancreas. Morphologic and immunocytochemical findings in 20 cases

OBJECTIVE

To analyze the role of fine needle aspiration (FNA) cytology in the preoperative diagnosis of pancreatic endocrine neoplasms.

METHODS

Cytologic and histologic diagnoses of pancreatic endocrine tumors were reviewed. A total of 20 FNA cytologic procedures from 20 patients were selected. A false positive case, a retroperitoneal paraganglioma, was also reviewed. Two groups of patients were established: (1) those in whom a surgical biopsy with an immunohistochemical study was available (n = 13), and (2) those with a pancreatic tumor in which the diagnosis was confirmed by immunocytochemical studies (n = 7). In 13 cases the pancreatic tumor was aspirated, while in 7, liver metastases were studied. The immunoexpression of chromogranin and synaptophysin was evaluated in alcohol-fixed smears from 12 and 11 cases, respectively.

RESULTS

One false negative and 1 false positive diagnosis were present. In the remaining 19 cases a cytologic diagnosis of pancreatic endocrine tumor was given. Main cytologic features were: (1) a prominent cellular dissociation with many single cells and small, poorly cohesive groups; (2) intermediate to large size cells with ill-defined cytoplasm, naked or eccentric nuclei, and frequent binucleation; and (3) variable nuclear pleomorphism with the characteristic finely granular distribution of the chromatin. Immunocytochemical evidence of endocrine differentiation (chromogranin or synaptophysin) was present in the 12 cases analyzed.

CONCLUSION

FNA cytology offers the possibility of a precise preoperative, noninvasive diagnosis of pancreatic endocrine tumors. Cytologic features differ considerably from those of pancreatic adenocarcinoma, allowing differentiation from nonfunctioning endocrine neoplasms. In difficult cases immunocytologic studies are very helpful.

Cytologic features of clear cell carcinoma of the female genital tract. Diagnostic value of the "raspberry body" in nonexfoliative cytologic specimens

OBJECTIVE

To evaluate the presence of basement membrane stromal material in fine needle aspiration (FNA) and scrape cytologic specimens from patients with clear cell carcinoma (CCC) of the female genital tract.

STUDY DESIGN

The study group consisted of 6 patients with CCC (5 ovarian and 1 cervical). Four samples corresponded to FNA specimens and 3 to scrape material obtained during intraoperative consultation for ovarian tumors. FNA was performed on a pelvic recurrence and on liver, pulmonary and lymph node metastases. The 6 cases had a complete histopathologic study.

RESULTS

In addition to large, clear cells, all cases showed basement membrane stromal material that assumed several forms. The most common was globular, hyaline structures, either naked or surrounded by neoplastic epithelial cells ("raspberry bodies"). Other fragments were larger, with several spherules and elongated prolongations. Scrape material showed stromal material resembling reduplicated basement membrane material. In Diff-Quik-stained smears (QCA, Tarragana, Spain) it showed metachromatic staining with a pink to purple color. Its recognition on Papanicolaou-stained smears was more difficult since it did not stain or was gray.

CONCLUSION

Basement membrane stromal material and, more precisely, "raspberry bodies," are a characteristic cytologic feature of CCC of the female genital tract. The combination of clear, atypical cells and basement membrane stroma is highly specific to this neoplasm and can be observed not only in exfoliative specimens but also in FNA and scrape samples.

Cytologic features of round cell liposarcoma: a report on five patients

BACKGROUND

Round cell liposarcoma (RCL) and myxoid liposarcoma are now considered as a single pathologic entity for several reasons. Despite many similarities, both morphologic phenotypes may differ considerably, and RCL may be difficult to recognize as liposarcoma. In addition, few cytologic reports describing features of RCL are available.

METHODS

Five patients with RCL for whom cytologic study of the tumor was available were reviewed. Only tumors in which round cell or poorly differentiated, hypercellular areas comprised > 75% of the tumor were considered RCL.

RESULTS

Smears were hypercellular and consisted of single, round cells with scarce cytoplasm and naked nuclei. Some cells showed slightly oval rather than round nuclei. In three tumors, the background was vacuolated; and, in two tumors, intracytoplasmic vacuoles were present. Isolated fragments of myxoid stroma containing neoplastic cells were identified in two tumors. Pleomorphism was not a prominent finding.

CONCLUSIONS

RCL may show morphologic features that are uncommon for a conventional liposarcoma, leading to an erroneous cytologic interpretation. This variant of liposarcoma must be considered when evaluating round cell neoplasms, mainly in adult patients. The presence of oval cells, vacuoles (intracytoplasmic or extracellular), and myxoid stroma should raise this diagnostic possibility, avoiding confusion with other well-known round cell neoplasms.

Fine-needle aspiration cytology of extranodal natural killer/T-cell lymphoma

Extranodal NK/T-cell lymphoma, nasal type, is a predominantly extranodal lymphoma characterized histologically by prominent necrosis, angiocentric growth, and vascular destruction. Only one report describing its fine-needle aspiration (FNA) cytologic features is available and shows highly unusual findings for a lymphoma. The present case concerns a 58-yr-old patient that presented with a soft tissue mass of the thigh in addition to an ulcerative lesion of the palate and nodular hepatic and splenic lesions. FNA cytology of the thigh tumor was interpreted as a malignant mesenchymal lesion (sarcoma). The subsequent pathologic study revealed an NK/T-cell lymphoma. Our findings are very similar to those previously reported. They were highly unusual for a lymphoma and consisted of polymorphic, round to spindle neoplastic cells distributed in irregular aggregates, and single cells. No significant number of lymphoglandular bodies were present.

Cytologic features of alveolar soft part sarcoma: report of three cases

Alveolar soft part sarcoma (ASPS) is a rare, high-grade, epithelial-like sarcoma that shows characteristic histopathologic findings. Although a chromosomal anomaly that seems specific has been recently described, its diagnosis is based on histologic and ultrastructural features. The tumor shows no specific immunohistologic findings. Cytologic features of three cases of ASPS are presented. Preoperative fine-needle aspiration (FNA) of the primary soft tissue tumor was performed in two cases. In another two, mediastinal and pulmonary and subcutaneous metastatic lesions were aspirated. In all cases the cytologic image was identical with numerous, dissociated, large neoplastic cells with round-to-plasmocytoid morphology. Cytoplasmic fragility and granularity with abundant, atypical, naked nuclei were present. In one case, FNA material was available for ultrastructural studies. It disclosed the characteristic cytoplasmic crystalline structures. A specific cytologic diagnosis of ASPS was given in all cases. In conclusion, ASPS is a rare neoplastic entity that shows a characteristic cytologic image. When accompanied by an adequate clinical context it permits specific preoperative recognition. While immunocytologic studies are helpful to exclude other neoplasms, ultrastructure may result in an exact diagnosis.

Fine-needle aspiration cytology of Kikuchi's lymphadenitis: a report of ten cases

The purpose of this study was to evaluate the cytologic features of Kikuchi's lymphadenitis (KL). Smears from 10 patients with histologically proven KL were reviewed. In all cases, fine-needle aspiration (FNA) was performed prior to biopsy. To assess the validity of morphologic recognition, a blinded study, including smears from non-Hodgkin's lymphomas, nonspecific, and mycobacterial lymphadenitis was performed. At least 5 cases showed characteristic cytologic findings that permitted their specific recognition. A polymorphous lymphoid population with abundant karyorrhectic debris and histiocytes, many of which showed a small size and eccentrically placed, crescent nuclei, were characteristic features of KL. The remaining 5 cases failed to show typical findings and were indistinguishable from other nonspecific, reactive lymphadenopathies. When typical cytologic findings are present in an adequate clinical context (cervical nodes in young patients), a precise diagnosis is possible, avoiding unnecessary biopsies.

Value of fine needle aspiration cytology in the initial diagnosis of Hodgkin's disease. Analysis of 188 cases with an emphasis on diagnostic pitfalls

OBJECTIVE

To evaluate the diagnostic accuracy and pitfalls of fine needle aspiration (FNA) cytology in the initial evaluation of Hodgkin's disease (HD) and to assess the influence of the pathologist's experience by comparing the results during two periods.

STUDY DESIGN

A total of 170 cytodiagnoses of HD were reviewed and compared with those on the final histopathologic report. Thirty-three cases of HD with a previous, different cytologic diagnosis were also selected. In all the cases under study, FNA was performed as part of the initial diagnostic approach. From a practical perspective, diagnostic errors were divided into major or minor according to the consequences on patient management.

RESULTS

Fifteen cytologic diagnoses of HD were followed by a different histologic diagnosis after lymph node biopsy. In 33 cases of HD an erroneous cytologic diagnosis was given prior to biopsy. The sensitivity of the series was 82.4% (86.1% excluding nonrepresentative cases). The positive predictive value reached 91.2%. Sensitivity varied from 79.3% in the first period (1982-1990) to 84.9% in the second (1991-1999) (83.3% and 88.2%, respectively, excluding nonrepresentative cases). Similarly, the positive predictive value increased from 89% to 92.8%. Diagnostic errors with important consequences for patient management diminished from 14 in the first period to 5 in the second.

CONCLUSION

Cytology offers a rapid and accurate approach not only for the diagnosis of recurrent HD but also for its initial recognition. These results increase the capacity of FNA as a first-level diagnostic technique in the screening of lymphadenopathies.

Fine needle aspiration cytology of follicular dendritic cell sarcoma. A case report

BACKGROUND

Follicular dendritic cell (FDC) sarcoma is a rare, recently described neoplasm that shows differentiation similar to that of follicular dendritic cells. It must be differentiated from metastatic neoplasms and other rare, nonlymphoid nodal lesions.

CASE REPORT

A 76-year-old man underwent fine needle aspiration of a recurrent laterocervical mass. Sixteen months earlier, the original tumor was excised and proved to be an FDC sarcoma. Smears exhibited a dual cell population composed of large cells with abundant cytoplasm and a lymphoid component that consisted mainly of lymphocytes and plasma cells. Large cells were atypical and distributed in ill-defined groups and as single cells. Nuclei were round to oval and pleomorphic, with irregular contours and nucleoli. Binucleation and multinucleation were occasionally seen. After the cytologic diagnosis, the tumor was excised and showed typical histologic and immunophenotypic features of FDC sarcoma.

CONCLUSION

The morphologic features of FDC sarcoma seem characteristic enough to permit its preoperative recognition. Its cytologic definition increases our knowledge of rare, nonlymphoid, primary nodal tumors, allowing better differentiation from metastatic neoplasms.

Cytologic diagnosis of leishmaniasis in HIV infection. A report of eight cases

BACKGROUND

Leishmania organisms are among the intracellular microorganisms with a tendency to develop in patients with the acquired immunodeficiency syndrome (AIDS). With increasing travel to endemic areas by patients with human immunodeficiency virus (HIV) infection, it is becoming a more-frequent diagnosis in nonendemic areas.

CASES

Ten cytologic specimens from eight patients with leishmaniasis and AIDS were reviewed. Eight samples were obtained from lymph nodes through fine needle aspiration (FNA). Another sample was obtained after scraping a tongue ulcer. The last one was an ascitic fluid specimen. Smears showed numerous parasitized histiocytes with abundant intracellular Leishmania organisms (amastigotes). Extracellular microorganisms were also abundant. Diff-Quik-stained smears allowed the clear recognition of the characteristic morphologic appearance with a deep-staining area (nuclei) and paranuclear zone (kinetoplast). Intracellular organisms were round, while single, extracellular forms were a more elongated.

CONCLUSION

The polymorphous clinical manifestations usually seen in patients suffering from leishmaniasis and AIDS constitute a diagnostic challenge that can be facilitated by cytopathologic examination. Cytology permits easy and rapid identification of Leishmania amastigotes, allowing a specific diagnosis and treatment.

Fine-needle aspiration cytology of mesenchymal hamartoma of the liver

The cytologic appearance of mesenchymal hepatic hamartoma in a 2-yr-old boy is described. Smears disclosed small groups and isolated, benign-appearing spindle cells admixed with scarce amounts of myxoid stroma and normal ductal cells and hepatocytes. Although the findings were nonspecific, cytology may rule out many other diagnostic possibilities and increases the preoperative capacity of clinical and image studies, leading to a more rational therapeutic decision.

Fine needle aspiration cytology of breast fibroadenoma. A cytohistologic correlation study of 405 cases

OBJECTIVE

To evaluate the cytohistologic correlation of breast fibroadenoma (FA) in order to assess the value of cytology in the conservative management of this lesion.

STUDY DESIGN

A retrospective analysis of all aspirates diagnosed as FA or fibroadenomatous lesion (n = 1,549) for which a histologic follow-up study was available (n = 362). Forty-three aspirates, including 14 nonrepresentative smears, from histologically proven FAs with a different cytologic report were also included in the study.

RESULTS

Cytohistologic agreement was present in 287 of the 362 cytodiagnoses. Lack of correlation was observed in 75 cases. Most diagnostic errors accumulated in the older patient group. The sensitivity of the cytologic diagnosis of FA was 86.9% (90.8% excluding nonrepresentative cases), with a positive predictive value of 79.3%. In 43 cases a histologic diagnosis of FA was given after previous erroneous (n = 29) or nonrepresentative cytodiagnoses (n = 14). The specificity of the cytologic diagnosis of FA reached 93.8%, with a negative predictive value of 96.3% (97.5% excluding nonrepresentative cases). Regarding malignancy, five tumors were diagnosed as FA and were malignant. No false positive diagnoses of malignancy were given, but nine aspirates were included in the category "suspicious for carcinoma."

CONCLUSION

FA of the breast remains a diagnostic challenge for the cytopathologist. A considerable amount of benign breast lesions can mimic FA on cytology, and such diagnostic categories as "fibroadenomatous lesion" or "consistent with FA" are associated with low diagnostic accuracy. While the cytologic requisites for entering a program of conservative management of FA are established, it seems that strict diagnostic criteria should be applied even at the expense of diminishing sensitivity.

Hodgkin's disease mimicking suppurative lymphadenitis: a fine-needle aspiration report of five cases

Spontaneous, suppurative-necrotizing changes associated with Hodgkin's disease (HD) are not infrequent. They are mostly observed in the nodular sclerosis variant of HD and can cause an erroneous histologic diagnosis of suppurative lymphadenitis. Few cytologic reports describing this presentation of HD are available. We describe 5 cases of HD that showed cytologic abscess-like smears dominated by a massive neutrophilic infiltrate and necrosis. Since therapy can induce similar changes, this study did not include patients with known HD. In 2 cases erroneously diagnosed as suppurative lymphadenitis, the presence of neoplastic cells was minimal and only detected after revision. A third case was misdiagnosed as abscessified metastasic carcinoma. Two cases were correctly identified as HD, although in one, the possibility of anaplastic large-cell lymphoma could not be ruled out. In conclusion, necrosis and massive neutrophilic infiltrates can occur spontaneously and can be prominent findings in smears from patients with HD, mainly the nodular sclerosis variant. The cytopathologist should always consider this possibility in the presence of an abscessified, suppurative, lymphadenitis-like aspirate. A detailed search for the characteristic neoplastic cells of HD is mandatory in these cases.

Cytologic features of malignant peripheral nerve sheath tumor

OBJECTIVE

To study the cytomorphologic features of malignant peripheral nerve sheath tumor (MPNST), including the epithelioid cell variant, and to establish differential diagnostic features with benign neurogenic tumors and other sarcomas.

STUDY DESIGN

Cytologic smears from primary, recurrent and metastatic tumors in 10 patients with MPNST were reviewed. Three patients had neurofibromatosis 1 (NF1), and in two others the tumor arose from a preexisting neurofibroma. Immunocytochemical evaluation of S-100 protein was performed in four cases. A complete pathologic study was available in all cases. To assess the validity of morphologic recognition, a blinded study, including eight cases of spindle MPNST among smears from histologically proven schwannomas, synovial sarcomas, leiomyosarcomas, malignant fibrous histiocytomas and liposarcomas, was performed.

RESULTS

Neurogenic differentiation was recognizable in four cases (differentiated), while the other four (anaplastic) were indistinguishable from other pleomorphic sarcomas. The presence of elongated, slender, often wavy nuclei and less commonly a delicate, fibrillary metachromatic stroma were features suggestive of nerve sheath differentiation. Other cytologic, as well as clinical, features permitted their identification as malignant. Two cases of epithelioid MPNST disclosed large, polygonal to plasmocytoid tumor cells without specific cytologic features. S-100 immunoexpression was positive in two of the four cytologic samples tested.

CONCLUSION

Although no morphologic findings are specific to MPNST, the above-mentioned cytologic features may suggest, in differentiated cases, its neurogenic differentiation. On the basis of morphologic features alone, the diagnosis of anaplastic and epithelioid MPNST is not possible, and immunocytochemical and ultrastructural studies are necessary. A specific cytodiagnosis is possible in recurrences, metastases and cases of NF1 or a preexisting neurofibroma.

HIV-1 (p24)-positive multinucleated giant cells in HIV-associated lymphoepithelial lesion of the parotid gland. A report of two cases

BACKGROUND

Cystic benign lymphoepithelial lesion (CBLL) is a well-recognized parotid disorder the diagnosis of which can be made on the basis of clinical findings, human immunodeficiency virus (HIV) testing, image studies and fine needle aspiration (FNA). Most aspirations are cystic, and the lesion can be recognized if the triad of foamy macrophages, lymphoid and epithelial (squamous) cells is observed.

CASES

The authors recently observed FNA cytologic features of two HIV-associated cases that exhibited numerous multinucleated giant cells (MGCs) but failed to show the epithelial component. A subsequent surgical resection was performed in one patient. Similarly to what has been described for nasopharyngeal (adenoid and tonsil) lymphoid tissue of HIV-positive patients, intense immunoexpression of S-100 and p24 (HIV-1) protein was present in MGC.

CONCLUSION

The diagnosis of HIV-associated CBLL should always be considered if a parotid cystic lesion presents with numerous MGCs. Immunocytochemical detection of p24 (HIV-1) protein in MGC becomes a very useful diagnostic aid and extends to parotid CBLL many of those pathogenic features of HIV-1 infection already noted in other HIV-1-infected, lymphoid oropharyngeal lesions.

Nodular pseudoangiomatous stromal hyperplasia of the breast. Cytologic features

OBJECTIVE

To define and discuss the cytologic findings in six cases of nodular pseudoangiomatous stromal hyperplasia (PASH) of the breast.

STUDY DESIGN

Retrospective evaluation of the medical records, cytologic and histologic material from six patients with palpable mammary PASH. Cases in which PASH was associated with other predominant mammary lesions were not included in the study.

RESULTS

A total of six patients with histologically proven PASH underwent aspiration in nine occasions (three patients studied twice). Clinically, five patients were diagnosed as having fibroadenoma or another benign lesion, and in one patient carcinoma was suspected. In two patients, mammography disclosed rapid growth of the lesion. Seven aspirations, performed on five patients, were diagnosed as fibroadenoma (n = 5) or fibroadenomatous lesion (n = 2). An eighth aspiration was cystic and reported as fibrocystic disease. The last case was erroneously diagnosed as suspicious for carcinoma. Even after revision, the cytologic similarities of PASH with fibroadenoma were remarkable. Most smears were less cellular than those of conventional fibroadenomas. Epithelial clusters showed variable size, with a predominance of medium to small groups. Stromal elements were minimal or absent. Background cellularity was composed of round to oval naked nuclei and others with spindle shapes. Occasional epithelial clusters showed cellular dissociation and slight atypia.

CONCLUSION

Due to the absence of specific cytologic features and similarities to fibroadenoma, a precise diagnosis of PASH cannot be made on cytologic material. However, the majority of cases can be diagnosed correctly as benign, allowing appropiate treatment.

Cytologic features of synovial sarcoma with emphasis on the monophasic fibrous variant: a morphologic and immunocytochemical analysis of bcl-2 protein expression

BACKGROUND

Monophasic fibrous synovial sarcoma (SS) is the most common variant of SS but few cytologic studies concerning this entity are available. bcl-2 protein immunoexpression has been described as a characteristic marker of SS and is useful for its differentiation from other sarcomas.

METHODS

Twelve cytologic specimens from 11 patients with histologically proven SS were reexamined. Ten samples were obtained by fine-needle aspiration and in two cases fluid from cystic tumoral areas was obtained at surgery. Nine cases corresponded to monophasic fibrous tumors and two to biphasic tumors. Immunoexpression of bcl-2 was evaluated in all histologic specimens and in six cytologic samples. bcl-2 protein also was evaluated in 13 soft tissue tumors.

RESULTS

All cytologic specimens had a similar appearance. Most smears were highly cellular and were comprised of densely packed, tridimensional groups and numerous isolated, round to oval cells. Remarkable findings included cellular monomorphism and vascular structures within the cell groups. Only one case showed cytologic evidence of epithelial differentiation. Immunoexpression of bcl-2 protein was present in 10 of the 11 histologic specimens (90.9%) and in 5 of the 6 cytologic samples (83.3%). A positive result also was observed in malignant fibrous histiocytoma, dermatofibrosarcoma protuberans, infantile hemangiopericytoma, pleomorphic liposarcoma, and malignant solitary fibrous tumor.

CONCLUSIONS

Although cytomorphologic features of SS are characteristic enough to permit its recognition, clinical correlation is necessary for its correct diagnosis. The immunoexpression of bcl-2 protein is not specific of SS and other soft tissue tumors can show a similar positive reaction.

Fine-needle aspiration cytology of mammary fibromatosis: report of two cases

The purpose of this study is to evaluate cytologically two cases of mammary fibromatosis (MF). Prior to FNAC, clinical and mammographic suspicion of carcinoma and fibroadenoma were present. In both cases cytology disclosed the presence of numerous spindle cells admixed with epithelial cells. In the first case, carcinoma was excluded and the diagnosis of "spindle-cell proliferative lesion" was established. The second case was erroneously diagnosed as "cellular fibroadenoma" due to the presence of monolayered ductal epithelial groups and stromal tissue. In both cases local excision of the lesion was recommended. Although in a strict sense fibromatosis is a pure stromal lesion, the frequent presence of epithelial groups in the smears should raise a differential diagnosis with other more frequent mixed (epithelial and stromal) lesions such as fibroadenoma, cystosarcoma phyllodes, and metaplastic carcinoma. Due to the fact that clinically and mamographically MF is frequently confused with malignancy, preoperative recognition is essential since in many cases it would avoid unnecessary radical surgery. In this sense cytology offers very important preoperative information.

Fine needle aspiration cytology of pleomorphic adenoma. An analysis of 212 cases

OBJECTIVE

To assess the value of fine needle aspiration cytology (FNAC) in the diagnosis of pleomorphic adenoma and to determine the cytologic variations responsible for diagnostic errors.

STUDY DESIGN

We retrospectively studied 212 cases cytologically diagnosed as pleomorphic adenoma. In 184 a histologic diagnosis was available. Fourteen cases of histologically proven pleomorphic adenomas with a previously erroneous cytologic diagnosis were also reviewed. This study was based on those cases with a histologic diagnosis.

RESULTS

The sensitivity and specificity of the cytologic diagnosis of pleomorphic adenoma in our series were 92.6% and 98.4%, respectively. In relation to malignancy, the series showed six false negative and three false positive diagnoses. In those cases correctly diagnosed on aspiration (175), a typical cytologic appearance, with no diagnostic difficulties, was observed in 118 cases (67.4%); the remainder showed cytologic variations. Cellular atypia (20.6%), cystic transformation (7%) and the presence of a cylindromatous pattern (5%) resembling adenoid cystic carcinoma were the most common cytologic variations observed and responsible for the majority of the errors.

CONCLUSION

The cytologic variations in FNAC of pleomorphic adenoma must be considered in order to avoid important errors in the preoperative management of and surgical approach to salivary gland lesions.

Primary renal angiosarcoma. Case report and review of the literature

Primary angiosarcoma is one of the rarest kidney tumors. Only six satisfactorily documented cases have been reported in the literature. A new case is described. The tumour is usually in an advanced clinical stage when detected, and generally first presents with local pain and no urinary symptoms.