Cytological Features That Differentiate Follicular Neoplasm from Mimicking Lesions

BACKGROUND: It is difficult to correctly diagnose follicular neoplasms (FNs) on fine-needle aspiration cytology (FNAC) because it shares many cytological features with other mimicking lesions. The aim of this study was to identify the cytological features that differentiate FNs from mimicking lesions. METHODS: We included the cytological slides from 116 cases of thyroid FN diagnosed on FNAC, and included their subsequent histological diagnoses. We evaluated the cytological architectural pattern and nuclear features of the lesions according to their histological groups. RESULTS: The final histological diagnoses of the 116 cases varied, and included 51 FNs (44%), 47 papillary thyroid carcinomas (40%) including follicular variant, and seventeen cellular nodular hyperplasias (15%). Regardless of the final histological diagnosis, microfollicular pattern was observed in most cases. On the other hand, trabecular pattern was identified in 34% of FNs, but not in any other lesions. Additionally, elongated nuclei and ground glass chromatin were found in only some papillary thyroid carcinomas. CONCLUSIONS: This study shows that the trabecular pattern is a representative cytological feature of FNs that can be used to distinguish FNs from mimicking lesions. In addition, nuclear shape and chromatin pattern can be used to further confirm the diagnosis of FNs from mimicking lesions through FNAC.

Importance of Individual Ghost Cells in Fine-Needle Aspiration Cytology Diagnosis of Pilomatricoma

BACKGROUND: Although histological diagnosis of pilomatricoma is not difficult because of its unique histological features, cytological diagnosis through fine-needle aspiration cytology (FNAC) is often problematic due to misdiagnoses as malignancy. METHODS: We reviewed the cytological features of 14 cases of histologically-proven pilomatricoma from Korea Cancer Center Hospital, with a discussion on the diagnostic pitfalls of FNAC. RESULTS: Among 14 cases of pilomatricoma, 10 (71.4%) were correctly diagnosed through FNAC, and two (14.3%) were misdiagnosed as carcinoma. Cytologically, all cases had easily recognizable clusters of basaloid cells and foreign body-type multinucleated cells. Although ghost cells were also found in all cases, some were inconspicuous and hardly recognizable due to their small numbers. CONCLUSIONS: An accurate diagnosis of pilomatricoma in FNAC is feasible with consideration of clinical information and close examination of ghost cells.

Cytologic Evaluation of CellPrep(R) Liquid-based Cytology in Cervicovaginal, Body Fluid, and Urine Specimens: Comparison with ThinPrep(R) / 대한세포병리학회지

This study purposed to evaluate a CellPrep(R) (CP) of liquid-based cytology (LBC) to search for a less expensive and automated alternative cytologic preparation technique applicable to usually encountered cytologic specimens. Cervicovaginal direct-to-vial split samples from 457 gynecologic patients, 40 body fluid samples, and 34 urine samples were processed with the CP technique and the results were compared with those of currently used ThinPrep(R) (TP) method. Both CP and TP methods provide evenly distributed thin layers of cells with little cellular overlaps or significant obscuring elements in most of cases. Staining quality of both preparations showed a little difference due to the difference of fixative solutions without significant distractions in cytologic interpretation. On the supposition that TP was a gold standard, sensitivity, specificity, positive predictive value, and negative predictive value of CP cytology were 89%, 98%, 86%, and 99% in the cervicovaginal smear, 89%, 82%, 80%, and 90% in body fluid, and all of these values were 100% in urine samples. To testify the availability of immunohistochemistry on CP preparations, cytokeratin, vimentin, and Ki-67 were applied on body fluid specimens, and all of these antibodies were specifically stained on targeted cells. Conclusively, the CP method gave comparable results to those of TP in terms of smear quality and cytologic diagnostic evaluation, and was available on immunohistochemistry. The CP method could offer a cost-effective and automated alternative to the current expensive techniques of liquid- based cytology on popular cytologic materials including cervicovaginal, body fluid, and urine specimens.

Fine Needle Aspiration Cytologic Features of Follicular Lymphoma / 대한세포병리학회지

The accuracy of fine needle aspiration cytology(FNAC) for the diagnosis of follicular lymphoma was investigated by a review of 13 FNAC specimens from 10 patients. All patients included in this study were confirmed by surgical biopsy preceded by FNAC. Three aspirates were unsatisfactory because of scanty cellularity. Among the remaining 10 cases, 5(50%) were diagnosed as lymphoma, 3(30%) as reactive hyperplasia, one(10%) as metastatic small cell carcinoma, and one(10%) as granulomatous inflammation. Cytologic distinction between follicular lymphoma and reactive hyperplasia is very difficult with cytomorphology alone. Compared to reactive hyperplasia, the characteristic cytologic features such as relatively homogeneous cellular constituent, paucity of tingible body macrophages and lymphohistiocytic aggregates, and less mitotic activity in follicular lymphoma are important findings to prevent false negative diagnosis. In addition, lymphoglandular bodies are useful in distinguishing malignant epithelial tumor from lymphoid lesion.

Cytologic Features of Well Differentiated Hepatocellular Carcinoma / 대한세포병리학회지

The fine needle aspiration biopsy(FNAB) has become a popular method to diagnose mass lesions of the liver. Although many reports have listed FNAB criteria to be used to diagnose hepatocellular carcinoma(HCC), a diagnostic dilemma still exists at the extreme ends of the spectrum, particularly for well differentiated HCC. The authors reviewed a series of FNAB specimens of the liver to distinguish well differentiated HCC from nonneoplastic liver. Fifteen cytologic features were examined in this study: high cellularity, large sheet formation, trabecular pattern, acinar pattern, dispersed pattern, irregular arrangement, increased nuclear/cytoplasmic ratio, naked nuclei, irregular chromatin, irregular nuclear contour, multinucleation, uniform macronucleoli, multiple nuclei, uniform small cytoplasm and monotony of atypia. These features were examined in a series of 76 FNAB specimens. Fifty two specimens were from patients with HCC and 24 specimens were from patients with nonneoplastic lesion or tumors other than HCC containg adequate amount of nonneoplastic hepatocytes in smear. All specimens were coded as to the presence or absence of the above cytologic features. With the use of stepwise logistic regression analysis, three features were identified as the key cytologic features predictive of HCC: irregular chromatin, monotony of atypia and absence of large sheet formation. When these criteria were used, the sensitivity diagnosing HCC by FNAB was 94.2%, specificity 100%, positive predictive value 100% and negative predictive value was 88.9%.