Using American Type Culture Collection Cell Lines to Evaluate Interlaboratory Variables for Estrogen Receptor and Human Epidermal Growth Factor Receptor 2 Immunostaining.

CONTEXT.­: Most laboratories currently use patient tissues for validating immunohistochemical stains. OBJECTIVE.­: To explore advantages of using cell lines with known antigenicity as a validation method. DESIGN.­: Five American Type Culture Collection (ATCC) cell lines with known negative, low positive, and moderate to strong estrogen receptor (ER) expression as well as negative, equivocal, and positive human epidermal growth factor receptor 2 (HER2) expression were cultured and made into cell blocks. One block from each cell line was fixed in formalin and another in ethanol before cell block preparation. Two sets of paired unstained slides from each block were sent to 10 different laboratories for HER2 and ER staining to be stained on runs from different days according to each laboratory's defined protocol. RESULTS.­: The 10 study participants evaluated 40 slides in a blinded fashion. For ER expression, all 80 interpretations for the ER strong and moderate positive cell lines had the target ER-positive result, and 74 of 80 ER-negative cell lines (92.5%) had agreement with the intended negative result. The ER low positive cell line showed varied but positive expression among all observers. The HER2 (3+)-positive cell lines yielded a target interpretation of 3+ in 65 of 80 interpretations (81.2%). For the HER2-negative cell line 69 of 78 interpretations (88.5%) were consistent with the target response (0 or 1+). No significant variation was observed between the ethanol- and non-ethanol-exposed cell lines, or between runs by the same laboratory. Variation from target results clustered within laboratories. CONCLUSIONS.­: This study indicates that variability between laboratories can be identified by using cell lines for quantitative or semiquantitative immunohistochemistry when using cultured cell lines of known antigenicity. These cell lines could potentially play a role in aiding anatomic pathology laboratories in validating immunohistochemistry tests for formalin- and ethanol-fixed tissues.

A brief description of the Bethesda System for reporting thyroid fine needle aspirates.

Fine needle aspiration has become the most prominent, and the easiest way, to morphologically evaluate lesions of the thyroid. When done correctly, the sensitivity and specificity of thyroid aspirates for detecting malignancy is very high. Unfortunately, clinicians are sometimes confused by the terminology used in thyroid cytopathology reports. One way to mitigate confusion is for all pathologists to use the same diagnostic criteria and terminology. Standardized terminology for thyroid cytopathology reports has recently been proposed. The following article introduces the concept of the Bethesda System for reporting thyroid aspirates. Sample diagnoses are given to illustrate how thyroid cytopathology reports may appear using the Bethesda System.

Diagnostic effects of prolonged storage on fresh effusion samples.

The effects on morphology and diagnostic interpretation of delayed processing of refrigerated effusion samples have not been well documented. The potential for cellular degeneration has led many laboratories to reflexively fix samples rather than submit fresh/refrigerated samples for cytologic examination. We sought to determine if effusion specimens are suitable for morphologic, immunocytochemical, and DNA-based molecular studies after prolonged periods of refrigerated storage time. Ten fresh effusion specimens were refrigerated at 4 degrees C; aliquots were processed at specific points in time (days 0, 3, 5, 7, 10, 14). Specimens evaluated included four pleural (3 benign, 1 breast adenocarcinoma) and six peritoneal (2 ovarian adenocarcinomas, 1 malignant melanoma, 2 mesotheliomas, 1 atypical mesothelial) effusions. The morphology of the cytologic preparations from the 10 effusions was preserved and interpretable after 14 days of storage at 4 degrees C. The immunocytochemical profile of the samples (AE1/AE3, EMA, calretinin, and LCA) was consistent from day 0 to day 14. Amplifiable DNA was present in all samples tested on day 14. We conclude that cytopathologic interpretation of effusion samples remains reliable with refrigeration at 4 degrees C even if processing is delayed.

Cytological identification of metastatic epithelial nephroblastoma in pleural fluid: report of a case and review of literature.

Nephroblastoma (Wilms' tumor) is the most common childhood renal tumor and usually presents with a histology and cytology consisting of blastemal, epithelial, and stromal cells. Effusions are not uncommon and may suggest an unfavorable prognosis when containing anaplastic tumor cells. In the present case, we report the cytological appearance of a Wilms' tumor metastatic to the pleura. The effusion consisted primarily of tumor cells demonstrating epithelial differentiation. The tumor cells mostly presented as three-dimensional aggregates in an inflammatory background. Many cystic and tubular structures were identified. The tumor cells demonstrated strong CD56 and WT1 immunoreactivity. The histology of a subsequent surgical specimen reflected the features seen in cytology.

Fine-needle aspiration of a Xp11.2 translocation/TFE3 fusion renal cell carcinoma metastatic to the lung: report of a case and review of the literature.

A 57-yr-old woman presented to the National Cancer Institute (NCI) with a history of nephrectomy for a clear cell renal cell carcinoma (RCC), Fuhrman grade 3 of 4 diagnosed 1 yr prior to admission to the NCI. A CT scan done upon admission revealed multiple bilateral lung masses. A CT-guided fine-needle aspiration (FNA) of one of the lung masses revealed a cellular specimen composed primarily of follicular structures surrounding dense hyalinized central cores. The cells in the follicular structures displayed bland nuclei and had granular to vacuolated cytoplasm. Papillary structures were also appreciated. Immunocytochemical studies showed tumor cells that were strongly vimentin and TFE3 positive. Focal staining for AE1/AE3 and CD10 was observed, as was negative staining for EMA. A surgical biopsy specimen reflected the FNA findings and demonstrated a similar immunoprofile. These findings correspond to the recently described Xp11.2 translocation/TFE3 fusion renal cell carcinoma. To our knowledge, this is the first report describing the cytologic features of an Xp11.2 translocation/TFE3 fusion RCC.

Detection of malignant hematopoietic cells in cerebral spinal fluid previously diagnosed as atypical or suspicious.

BACKGROUND: Involvement of the cerebrospinal fluid (CSF) by hematopoietic malignancies may be difficult to document by morphology alone. In cases with low numbers of cells or ambiguous morphology, the diagnoses of "atypical" or "suspicious" may be used. The significance of these diagnostic terms in this scenario has not been well established. METHODS: Between January 2000 and July 2004, 32 patients with known lymphoma or leukemia and an initial diagnosis of "atypical" or "suspicious" using morphologic criteria were identified. Subsequent flow cytometry (FC) and cytologic data from these patients were evaluated. RESULTS: Of the 32 patients with an initial diagnosis of "atypical" or "suspicious," 40.6% (n = 13) had negative first and subsequent FC and morphologic evaluation of their CSF samples with follow-up up to 1 year. Nineteen patients (59.4%) had malignant hematopoietic cells identified in subsequent CSF samples by cytology and/or FC. CONCLUSIONS: In patients with a previous history of lymphoma or a hematopoietic malignancy, a majority of the patients (59.4%) with an "atypical" or "suspicious" diagnosis on CSF will ultimately have malignant cells identified in the CSF by cytology and/or FC. Many of these patients can be identified more expediently with the concurrent utilization of flow cytometry.