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.

Micropapillary carcinoma of the renal pelvis and ureter.

PURPOSE: MPC located in the upper urinary tract is rare with only 2 cases reported to date. We report clinical and histopathological data on 26 patients to increase the knowledge of this rare entity. MATERIALS AND METHODS: A clinical and histopathological review was performed in 943 patients with a neoplasm in the renal pelvis or ureter, diagnosed between 1971 and 1998. We identified 26 patients with MPC. No patients were alive at the end of the study. RESULTS: Of the patients 11 had greater than 50% MPC and 15 had focal MPC (at least 10%). The incidence was 2.8%. Median patient age at diagnosis was 69 years (range 54 to 88) and the male-to-female ratio was 17:9. All except 4 patients had stage T3 disease or higher. Carcinoma in situ was identified in 64% of cases and vascular invasion was present in 81%. A total of 20 patients (77%) died of disease and only 7 survived longer than 5 years. CONCLUSIONS: The prognosis is poor since most patients with MPC of the renal pelvis and ureter initially present with advanced disease. Stage for stage the prognosis is not different from that in nonMPC urothelial cell carcinoma. Surgery is curative in less advanced cases. However, radiotherapy and systemic chemotherapy appear to be ineffective.