Cystic pancreatic neuroendocrine tumors: endoscopic ultrasound and fine-needle aspiration characteristics.

BACKGROUND AND STUDY AIMS: Limited data are available on the endoscopic ultrasound (EUS) and fine-needle aspiration (FNA) characteristics of cystic pancreatic neuroendocrine tumors (CPanNets). The aims of this study were to describe the EUS and FNA characteristics of pathologically confirmed CPanNets and to compare these characteristics with mucinous cysts from matched patients. PATIENTS AND METHODS: From an EUS - FNA database (between 1999 and 2011), 19 patients with a pathologically confirmed CPanNet were identified. Patient characteristics, cyst fluid carcinoembryonic antigen (CEA) levels, pathology, and EUS findings were analyzed. For comparison, age- and sex-matched patients with mucinous cysts were randomly chosen from the same database. RESULTS: Of the 19 patients, two had multiple endocrine neoplasia type 1 and two had metastases. The median diameter of the lesions was 24 mm. EUS revealed unilocular lesions in 7 patients, thinly septated lesions with thin walls in 1, and mixed solid-cystic lesions in 11. EUS - FNA cytology confirmed neoplasm in 12 of the 19 patients (63.2 %). The median cyst fluid CEA level (n = 15) was 1.1 ng/mL (range 0.3 - 500 ng/mL). Compared with matched patients with mucinous cysts, the median cyst fluid CEA was lower (1.1 ng/mL vs. 400 ng/mL), thick walls were more common (66.7 % vs. 13.3 %), and diagnostic cytology was more likely (73.3 % vs. 20.0 %). CONCLUSIONS: Analysis of EUS and FNA results showed that the cyst fluid from CPanNets had a lower CEA concentration, a higher frequency of thick walls on EUS, and higher diagnostic cytology compared with mucinous cysts. These findings may aid in the diagnosis of CPanNets.

Lymphangioma of the pancreas: a multimodal approach to pre-operative diagnosis.

BACKGROUND: Lymphangioma of the pancreas is an extremely rare benign tumour of lymphatic origin, with only four cases diagnosed by EUS-FNA reported to date. METHODS AND MATERIALS: Five cases of either cytologically or histologically diagnosed pancreatic lymphangioma with pre-operative cytological analysis by EUS-FNAC were reviewed. RESULTS: All patients were female, with a mean age of 56.4 years. By imaging, the cystic lesions ranged in size from 2 to 7 cm (mean 4.5 cm) and were mainly located in the head of the pancreas. All cysts had thin walls and no cyst demonstrated a mural nodule. Diagnosis based on imaging features was benign in all cases due to the absence of high-risk features. Four samples were sent for biochemical analysis, which showed low CEA levels (range, <0.5-19.4 ng/ml; mean, 5.45 ng/ml) and CA 19.9 and CA 72.4 levels within normal range. All cyst fluids showed numerous small lymphocytes with no atypia; no epithelial cells were present, including no gastrointestinal contamination. Flow cytometry in two cases showed T lymphocytes with a mature phenotype. Surgical resection in two patients confirmed the cytological diagnosis. Benign clinical follow-up was available in three patients at 2, 3 and 3.5 years. CONCLUSION: A multimodal approach to cytological diagnosis (combining clinical, radiological and cyst fluid gross, biochemical and cytological characteristics) can lead to the diagnosis of this cystic neoplasm and distinguish it from other more common cysts in the pancreas, potentially avoiding the need for unnecessary surgery.

Survey of medical training in cytopathology carried out by the journal Cytopathology.

This report of the Editorial Advisory Board of Cytopathology gives the results of a survey of medical practitioners in cytopathology, which aimed to find out their views on the current situation in undergraduate and postgraduate training in their institutions and countries. The results show that training in cytopathology and histopathology are largely carried out at postgraduate level and tend to be organized nationally rather than locally. Histopathology was regarded as essential for training in cytopathology by 89.5% of respondents and was mandatory according to 83.1%. Mandatory cytopathology sections of histopathology were reported by 67.3% and specific examinations in cytopathology by 55.4%. The main deficiencies in training were due to its variability; there were insufficient numbers of pathologists interested in cytology and a consequent lack of training to a high level of competence. Pathologists without specific training in cytopathology signed out cytology reports according to 54.7% of responses, more often in centres where training was 3-6 months or less duration. Although 92.2% of respondents thought that specialist cytology should not be reported by pathologists without experience in general cytopathology, that practice was reported by 30.9%, more often in centres with small workloads. The survey report recommends that 6-12 months should be dedicated to cytopathology during histopathology training, with optional additional training for those wanting to carry out independent practice in cytopathology. Formal accreditation should be mandatory for independent practice in cytopathology. When necessary, temporary placements to centres of good practice should be available for trainees intending to practise independently in cytopathology. There should be adequate numbers of pathologists trained in cytopathology to a high level of competence; some of their time could be released by training cytotechnologists and trainee pathologists to prescreen cytology slides and assess adequacy of fine-needle aspiration samples when immediate diagnosis was not required. The survey demonstrated a clear need for European and international guidelines for training in cytopathology.

Endoscopic ultrasound-guided fine needle aspiration cytology of the pancreas: a morphological and multimodal approach to the diagnosis of solid and cystic mass lesions.

Cytological evaluation of pancreatic masses and cysts is the preferred pre-operative diagnostic modality and is increasingly being performed by endoscopic ultrasound. This review focuses on the multimodal approach at the Massachusetts General Hospital that utilizes clinical, cytological, radiological and ancillary studies in rendering a final cytological diagnosis.

Malignant melanoma with a myxoid stroma: a diagnostic pitfall on fine-needle aspiration biopsy.

Malignant melanoma (MM), both primary and metastatic, may be associated with a prominent myxoid stromal reaction causing diagnostic confusion on fine-needle aspiration biopsy (FNAB), most often with sarcomas that demonstrate a myxoid stroma, particularly malignant peripheral nerve sheath tumor (MPNST). We present a case of a 32-yr-old man with no past medical history who presented with a unilateral neck mass clinically suspicious for lymphoma. FNAB produced a specimen composed of large sheets of anaplastic cells encased in a myxoid stroma that was S100 and vimentin-positive but HMB-45-negative. A diagnosis of MPNST was made. Excision demonstrated a metastatic MM of unknown primary, with a prominent myxoid stromal reaction. A repeat HMB-45 was again negative. Electron microscopy demonstrated intracytoplasmic melanasomes and cisternae of rough endoplasmic reticulum with intracisternal parallel tubules, confirming the diagnosis. Although HMB-45 is typically negative in both tumors, S100 should be strongly positive in myxoid MM and only focal in MPNST.

Fine-needle aspiration biopsy in the diagnosis and classification of primary and recurrent lymphoma: a retrospective analysis of the utility of cytomorphology and flow cytometry.

We retrospectively reviewed our experience with the fine-needle aspiration biopsy (FNAB) diagnosis of primary and recurrent lymphoma to assess the ability of cytomorphology with and without ancillary flow cytometry (FCM) analysis to diagnose and subclassify these tumors according to the Revised European-American Lymphoma/World Health Organization classifications. We reviewed 139 consecutive FNABS of 84 primary and 55 recurrent lymphomas. FCM was successful in 105 (75%) cases. The overall results, including cases without FCM, included 93/139 (67%) true positive, 7 (5%) false negative, and 39 indeterminate (27 [19%] suspicious and 12 [9%] atypical) diagnoses of lymphoma. In cases with FCM, there were 80/105 (77%) true positive, no false negative, and 25 indeterminate diagnoses (15 [14%] suspicious and 10 [9%] atypical). The overall results of the 84 primary lymphomas were 55 (67%) true positive, 5 (5%) false negative, and 24 indeterminate (14[16%] suspicious and 10 [12%] atypical) diagnoses for lymphoma. Of the 68 primary lymphomas analyzed with FCM, 50 [74%] were true positives, and 28 were indeterminate (11 [16%] suspicious and 7 [10%] atypical). There were no false negatives. Diagnostic accuracy varied among lymphoma subtypes. Subclassification of the positive cases were initially conclusive in only 55/93 cases (59%). However, a retrospective review of the morphologic together with FCM data in 15 of the 23 unclassified cases improved the overall subclassification of positive cases to 77%. Subclassification was best in small lymphocytic lymphoma/chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, Burkitt's lymphoma, mantle cell lymphoma, and plasmacytoma (all 100%). Subclassification was poor in marginal-zone lymphoma (33%), and initially as well in diffuse large B-cell lymphoma (62%), but it improved on review (95%), as did subclassification of follicular lymphoma (77 to 100% on review). Hodgkin's disease was recognized as malignant in only 44% of the cases (7/16) and was classified as such based on morphology alone. This review of our early efforts to diagnose and subclassify lymphoma with FNAB and FCM indicates that although a diagnosis and proper subclassification of lymphoma can be made with certainty in the majority of cases, recurrent or primary, it requires close coordination of cytomorphology and immunophenotyping data, which often comes with close cooperation of cytopathologists and hematopathologists. A mere cytological diagnosis of positive for lymphoma is no longer acceptable if FNAB is to become an independent diagnostic tool for lymphoma.

Fine-needle aspiration biopsy of papillary thyroid carcinoma: diagnostic utility of cytokeratin 19 immunostaining.

BACKGROUND: Papillary thyroid carcinoma is the most common malignant neoplasm of the thyroid gland, and fine-needle aspiration biopsy (FNAB) often is the initial diagnostic method used in its detection. Prior studies have shown that immunohistochemical staining for various cytokeratins in general, and cytokeratin 19 (CK19) in particular, can be applied as an ancillary technique for diagnosing papillary thyroid carcinoma in histologic specimens. In the current study the authors assessed the diagnostic utility of CK19 to detect papillary carcinoma effectively in cytologic preparations of thyroid FNABs. METHODS: Immunocytochemical staining with CK19 was performed on cytologic aspirates from 37 papillary thyroid carcinomas and 36 other lesions of the thyroid (14 follicular adenomas, 10 multinodular goiters, 5 cases of Hashimoto thyroiditis, 6 oncocytic [Hürthle cell] neoplasms, and 1 follicular carcinoma). All cases included in the study had a corresponding histopathology specimen. RESULTS: Positive immunocytochemical reactivity for CK19 was identified in 34 of 37 papillary carcinomas and in 1 of 36 other thyroid lesions (sensitivity of 92% and specificity of 97%). Although the strongest reactivity was obtained in methanol fixed thin layer preparations, the antibody also was effective in detecting papillary carcinoma in alcohol fixed and air-dried smears. The single false-positive case was a follicular adenoma with focal areas of papillary hyperplasia. All other aspirates including those from cases of Hashimoto thyroiditis, multinodular goiter, follicular adenoma, oncocytic neoplasms, and follicular carcinoma were negative. CONCLUSIONS: CK19 is an effective, highly sensitive, and specific ancillary tool for the diagnosis of papillary carcinoma in thyroid FNABs.

The clinical application and cost analysis of fine-needle aspiration biopsy in the diagnosis of mass lesions in sarcoidosis.

BACKGROUND: Sarcoidosis is a prevalent disease of unknown cause characterized by granulomatous inflammation that often creates deep and/or superficial mass lesions. Tissue samples are considered the "gold standard" in diagnosis; however, it is a medically treated disease. We analyzed the utility and relative cost-effectiveness of fine-needle aspiration biopsy (FNAB) in the clinical investigation of patients with both suspected and unsuspected sarcoidosis. METHODS: All FNAB cases with sarcoidosis either as the cytologic diagnosis or mentioned as part of the differential diagnosis were retrospectively reviewed for clinical history, follow-up, cytologic features, and surgical pathology findings. Comparative analysis of cost of FNAB and excisional biopsy were also made. RESULTS: Thirty-two FNABs in 28 patients included 17 women and 11 men. Anatomic sites included lymph node (n = 17), lung (n = 5), salivary gland (n = 8), and liver (n = 2). Sarcoidosis had already been diagnosed or was a clinical consideration prior to FNAB in 14 cases. Chest radiograph showed abnormal findings in 19 cases. Angiotensin-converting enzyme (ACE) was measured in seven patients and was elevated in four. All aspirates showed granulomatous inflammation; in 22 patients, special stains or cultures for microorganisms were negative. Simultaneous or subsequent excisional biopsies confirmed the FNAB findings in 17 patients. Institutional ratios of excisional biopsy to FNAB in the diagnosis of sarcoidosis ranged from 4 to 19:1. The cost of FNAB was only 12.5 to 50% that of tissue biopsy. CONCLUSIONS: FNAB appears to be underutilized in the diagnosis of sarcoidosis. When used in conjunction with radiologic and laboratory data, FNAB may be a reliable and cost-effective method of diagnosis, especially in patients with an established diagnosis of sarcoidosis.

Cytologic features of metastatic sebaceous carcinoma: report of two cases with comparison to three cases of basal cell carcinoma.

The cytologic findings of two cases of metastatic sebaceous carcinoma are described and compared to three cases of locally recurrent basal cell carcinoma. Morphological findings for sebaceous carcinoma in fine-needle aspiration biopsy (FNAB) smears included cellular, loosely cohesive cell clusters with central necrosis, squamous pearl formation, and adjacent keratin debris. The tumor cells had moderate amounts of vacuolated cytoplasm, round to oval vesicular nuclei with clumped chromatin, nucleoli, some nuclear overlap, and numerous mitotic figures. An interesting finding was the presence of numerous multinucleated giant cells, probably responding to extravasated lipid or keratin material. In contrast, the FNAB smears of basal cell carcinoma typically were less cellular, with more tightly cohesive and smaller clusters of uniform hyperchromatic basaloid cells with high nuclear to cytoplasmic ratios, and a narrow rim of cytoplasm without vacuolization. The morphologic features of sebaceous carcinoma in FNAB smears appear to be distinct from those of basal cell carcinoma. FNAB can be a useful preoperative diagnostic technique to distinguish these two cutaneous malignancies.

Ultrasound-guided fine-needle aspiration biopsy of the thyroid.

BACKGROUND: We reviewed the Massachusetts General Hospital experience with ultrasound-guided fine-needle aspiration biopsies (FNABs) of the thyroid to determine the indications, rate of unsatisfactory smears, correlation with excisional biopsy results, and verification of efficient use of personnel time. METHODS: All radiologically guided FNABs of the thyroid from January 1993 through June 1997 were reviewed. As a measure of efficient use of technologist time, a sample of times spent by the technologist during the procedure for 20 cases in 1993 and 1997 was compared with that of an equal number of random nonthyroid image guided FNABs. RESULTS: Two hundred-ninety FNABs were identified in 251 patients, representing 12% of all thyroid FNABs and 11% of all radiologically guided FNABs. Indications in the 251 patients included multiple nodules (78), solitary nodules (61), complex nodules (39), prior failed FNAB (39), thyroid bed abnormalities post-thyroidectomy (21), difficult access (7), and investigation of recurrent tumor in residual thyroid lobe (6). Available records indicated 118 lesions were palpable and 45 were nonpalpable; the physical examination characteristics of the remainder (88) were not stated. Diagnoses included 44 unsatisfactory cases (15%), 103 macrofollicular lesions, 20 microfollicular lesions, 26 mixed macro/microfollicular lesions, 5 oxyphilic lesions, 1 trabecular pattern, 15 nonspecific follicular cell pattern, 9 follicular cell atypia, 30 cysts, 11 thyroiditis, 23 malignant tumors, and 3 other (1 parathyroid, 2 lymph node). Eighty-nine FNABs from 76 patients had subsequent surgical biopsy. Excisional biopsies in 14 unsatisfactory FNABs were benign. In the remaining 75 FNABs from 67 patients, 18 malignancies on FNAB were correctly diagnosed, but 3 other papillary carcinomas were only qualified as atypical follicular cells on cytology. No false-positive cases occurred. Of 15 macrofollicular lesions on cytology, 10 were adenomas on excision, only 2 of which were microfollicular adenomas, and 4 were adenomatous nodules. An aspirate of a parathyroid adenoma was misinterpreted as a macrofollicular lesion of the thyroid. Three microfollicular lesions on FNAB proved to be nodular hyperplasia on excision, and the other 11 were adenomas, 5 of them microfollicular. Average technologist time was significantly longer for thyroid FNABs than nonthyroid FNABs in 1993, but in the 1997 sample no significant difference was identified. CONCLUSIONS: Radiologically guided FNAB of the thyroid is a clinically useful procedure with a high correlation between benign lesions not needing excision (macrofollicular), and lesions that need excision (microfollicular/oxyphilic cell or malignant). Technologist time needed for immediate evaluation tends to decrease with increasing operator experience. Cancer (Cancer Cytopathol)

Benign glandular cells in posthysterectomy vaginal smears.

OBJECTIVE: To investigate the occurrence and origin of benign glandular cells in posthysterectomy vaginal smears and to propose a categorization for these cells under the Bethesda system. STUDY DESIGN: Among 4,986 posthysterectomy vaginal smears during a 3.5-year period, 82 patients were identified with smears containing benign glandular cells. The review of the smears, related biopsies and charts form the basis of this report. A control group of 236 posthysterectomy smears without glandular cells from the same period was reviewed. RESULTS: Smears were available for review on 76 of 82 patients. All were within normal limits or showed benign cellular changes. All contained clearly benign glandular cells, most frequently present in groups. In all smears, pale pink-red intracellular mucin was identified either diffusely within the cytoplasm or within vacuoles. The glandular cells appeared as hybrid parabasal-endocervical type, squamous metaplastic or columnar cells. Associated cytologic findings included atrophy, inflammation, blood and repair. Reactive atypia was present in 10 (13%) cases. Biopsies were performed on 40 (48%), all showing benign changes. In four of five cases stained, intracellular mucin was seen within glandular cells. Chart review revealed that the patients' hysterectomies were performed for removal of a malignant tumor in 58 (71%) of the study group and in 100 (42%) in the comparison group and that 48 (58%) of the study group had received radiotherapy and/or chemotherapy, while only 26 (11%) of those in the comparison group had similar therapy. CONCLUSION: The presence of benign glandular cells in posthysterectomy vaginal smears is an infrequent but not rare finding. This study indicated an association with benign processes and showed a frequent association with prior radiation or chemotherapy. A more appropriate designation under the Bethesda System is "benign cellular changes" rather than "glandular cell abnormalities." An aggressive workup does not appear to be warranted in this group of patients. We speculate that this phenomenon represents a metaplastic process, possibly secondary to radiation or chemotherapy.

Fine needle aspiration biopsy of the liver. Principal diagnostic challenges.

Fine needle aspiration biopsy (FNAB) is the diagnostic procedure of choice for evaluation of liver lesions. Although primarily applied to malignant disease, it is also used in the evaluation of benign conditions. Improvements in imaging techniques and advances in cytologic interpretations, as well as production of new biopsy needles, have all contributed to the rapid increase in radiologically guided liver FNAB.

Aspiration cytology of malignant neoplasms associated with granulomas and granuloma-like features: diagnostic dilemmas.

BACKGROUND: Malignant lymphomas and solid tumors that mimic or are associated with epithelioid granulomas are widely recognized in surgical pathology, but have received little attention in the cytopathology literature. In this study the authors present their experience with six such cases in which the presence of granulomas or granuloma-like features posed a diagnostic difficulty on fine-needle aspiration cytology (FNAC). METHODS: Clinical data, FNAC, and follow-up surgical specimens from six patients presenting with neck masses were reviewed. RESULTS: Only one case was diagnosed confidently as metastatic squamous cell carcinoma with an extensive granulomatous response; the other five were interpreted as "atypical" with descriptive cytology and a differential diagnoses including granulomatous inflammation, in addition to a caveat of "cannot exclude malignancy." Biopsy studies in these cases were recommended in view of the atypical cytologic findings and strong clinical suspicion of malignancy in each case. The histologic findings in two cases revealed Hodgkin's disease with exuberant granulomatous response. The remaining three cases were found to be malignant neoplasms with epithelioid morphologic features and included one example each of diffuse large cell lymphoma, anaplastic carcinoma of the thyroid, and lymphoepithelial carcinoma. CONCLUSIONS: Malignancies associated with granulomas and tumor cells mimicking epithelioid histiocytes may be difficult to diagnose accurately on FNAC. The cytologic differential diagnosis of a "granulomatous" process should include malignant neoplasms. Excisional biopsy studies may be required for definitive diagnosis.

Urine cytology of primary and secondary urinary bladder adenocarcinoma.

BACKGROUND: Primary and secondary adenocarcinomas of the urinary bladder are uncommon, and the urine cytology of these tumors has rarely been described. Familiarity with the cytomorphology of these neoplasms may facilitate their detection in urine cytology specimens. METHODS: The authors reviewed 46 urine samples (19 voided, 19 instrumented, and 8 bladder washings) from 41 patients with biopsy-proven primary urinary bladder adenocarcinoma (n = 11) or metastatic adenocarcinoma (n = 35) from the prostate (n = 17), colon (n = 10), breast (n = 3), kidney (n = 3), or uterus (n = 1), or from unknown origin (n = 1). Cytomorphology, the role of cytology, and causes for negative diagnoses were evaluated. RESULTS: Cytologic diagnoses of malignancy, adenocarcinoma not otherwise specified, and adenocarcinoma of a specific type were given in 87%, 28%, and 39% of cases, respectively. Columnar cells, coarse chromatin, and necrosis were found in adenocarcinoma of the colon. Syncytial and acinar arrangements, round or oval nuclei, vesicular chromatin, and prominent nucleoli were commonly found in adenocarcinoma of the prostate. These features permitted us to make a specific diagnosis in 90% of cases of adenocarcinoma of the colon and 41% of cases of adenocarcinoma of the prostate. Cytologic examination failed to lead to a diagnosis of malignancy in 18% of primary adenocarcinoma cases. CONCLUSIONS: A large number of adenocarcinomas of the colon and prostate have sufficient cytologic features to suggest the correct diagnosis in urine samples. The cytomorphology of primary bladder adenocarcinoma is not as easily characterized. The submucosal nature of some metastatic deposits and tumor differentiation influence the diagnostic accuracy.

Cytology of germ cell tumors: extragonadal, extracranial masses and intraoperative problems.

BACKGROUND: Germ cell tumors (GCTs) and their metastases may be found in numerous sites that are accessible to cytologic sampling, and many are responsive to chemotherapy. METHODS: The authors reviewed 20 examples of GCT cytology from 16 males and 3 females ranging in age from 1.5 to 61 years (median, 34 years). With two exceptions, one benign cystic ovarian teratoma in which intraoperative cytology was used to diagnose an associated adult-type carcinoma and one undescended testis in which seminoma presented as an abdominal mass, the material reviewed included no examples of primary gonadal GCT. RESULTS: The authors studied 7 primary and 13 metastatic GCTs; these studies were based on 13 in vivo aspirations, 4 intraoperative preparations, and 3 samples of body cavity fluids. All samples were correctly interpreted as malignant, and only one was incorrectly classified as a non-GCT malignancy. CONCLUSIONS: Clinical and cytologic findings are useful in the diagnosis of GCTs and their metastases. Incorrect interpretation of these neoplasms as poorly differentiated malignancies of other types may deprive the patient of effective chemotherapy. Air-dried, Romanowsky-stained smear material and cell block sections may contribute to the resolution of diagnostic dilemmas.

The vascular architecture of renal cell carcinoma in fine-needle aspiration biopsies. An aid in its distinction from hepatocellular carcinoma.

BACKGROUND: The morphologic similarities between renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC) can cause diagnostic difficulty in fine-needle aspiration biopsy (FNAB) specimens. In the authors' prior study of liver FNAB, peripherally wrapping endothelium (PE) and arborizing transgressing endothelium (TE) were 100% specific for HCC relative to metastatic tumors, which included only three RCCs. In this study, the vascular patterns of RCC in FNAB were reviewed for comparison with HCC, to determine their usefulness in the differential diagnosis of HCC and RCC. METHODS: FNAB of 49 RCCs (26 primary and 23 metastatic) from 46 patients were reviewed. Four vascular patterns were assessed: PE, TE, papillary endothelium (PAP) in fibrovascular cores of papillary fragments, and short nonbranching endothelium (SE) in small cell clusters. Each pattern was given a semiquantitative score: absent (0), focal (1), or extensive (2). Cellularity was categorized as low (< 20 groups), moderate (20-50 groups), or high (> 50 groups). RESULTS: Vessels were present in 19 of 26 (73%) primary and 9 of 23 (39%) secondary RCC. PE was not identified. TE was observed in 11 primary (42%) and 7 metastatic (30%) RCC. SE was present in 5 primary (19%) and 1 metastatic (4%) RCC. The TE and SE patterns were distributed among the clear cell, granular cell, and chromophobe RCC. PAP was observed in all four papillary RCC. The majority of the TE and all of the PAP were present in moderately to highly cellular FNABs, whereas SE was usually observed in FNABs with low cellularity. CONCLUSIONS: FNAB specimens of RCC commonly contain TE, as in HCC, but lack PE. TE was less frequent in metastatic than primary RCC. Other vascular patterns (SE, PAP), absent in HCC, were observed infrequently. Vascular patterns, especially PE, are useful in distinguishing HCC from RCC.

The usefulness of the reticulin stain in the differential diagnosis of liver nodules on fine-needle aspiration biopsy cell block preparations.

We reviewed fine-needle aspiration biopsy (FNAB) cell blocks of hepatocellular carcinoma (HCC) (n = 16) and benign hepatic processes (n = 16) to evaluate the significance of reticulin staining (Gomori stain) in combination with standard cytomorphologic and architectural criteria. We analyzed the staining pattern using semiquantitative grading: normal, variable, decreased, or virtually absent. Also, we graded the cell thickness of the hepatic trabeculae as greater than or less than three cells. Fourteen of 16 biopsy specimens of benign processes demonstrated a normal reticulin framework, with staining outlining hepatic trabeculae less than three cell layers in thickness. Staining was markedly decreased in one case of steatosis and virtually absent in one case of cirrhosis. In contrast, all of the 16 HCCs demonstrated either a virtually absent (7 of 16), decreased (6 of 16), or variable (3 of 16) reticulin staining pattern, with thickened trabeculae greater than three cell layers. We conclude that the reticulin stain is a useful adjunct in the differential diagnosis of liver nodules on FNAB cell block preparations and that it is particularly useful in distinguishing HCC from benign hepatic processes. Virtually absent or decreased reticulin staining and staining outlining trabeculae greater than three cells in thickness support the diagnosis of HCC. Normal reticulin staining outlining well-defined hepatic trabeculae less than three cell layers in thickness supports the diagnosis of a benign hepatic process.

Diagnostic pitfalls of aspiration cytology of salivary duct carcinoma.

BACKGROUND: Salivary duct carcinoma (SDC) is a highly aggressive primary salivary gland neoplasm that resembles intraductal and infiltrating breast carcinoma histologically. The purpose of this study was to review the cytologic features of histologically proven salivary duct carcinomas and to identify the potential pitfalls in cytologic diagnosis. METHODS: Fine-needle aspiration cytology of nine histologically proven salivary duct carcinomas was reviewed. RESULTS: The patients' age ranged from 62 to 89 years (median, 69 years). There were eight males and one female. The cytologic diagnoses of these cases were as follows: pleomorphic adenoma (PA) (three cases), high grade carcinoma, not otherwise specified (three cases), mucoepidermoid carcinoma (MEC) (two cases), and atypical cytology with differential diagnosis including MEC, oncocytoma, and acinic cell carcinoma (one case). The spectrum of cytologic findings included broad flat sheets and three-dimensional clusters. There was mild to severe cellular pleomorphism and nuclear atypia. Papillary clusters and cribriforming occasionally were identified. Bland cytologic features and prominent hyaline stroma, shown to represent the dense fibrosis on histologic sections, were identified in three cases cytologically interpreted as PA. CONCLUSIONS: Fine-needle aspiration of SDC may be difficult to interpret accurately, and bland cytomorphologic features in some cases may lead to a false-negative interpretation; several clinically important pitfalls are demonstrated in our series.