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Using the Mitosis-Specific Marker Anti–Phosphohistone H3 to Assess Mitosis in Pulmonary Neuroendocrine Carcinomas

Koji Tsuta MD, PhD, Diane C. Liu MS, Neda Kalhor MD, Ignacio I. Wistuba MD, Cesar A. Moran MD
DOI: http://dx.doi.org/10.1309/AJCPDXFOPXGEF0RP 252-259 First published online: 1 August 2011

Abstract

Counting mitotic figures (MFs) is one of the essential factors for determining the histologic grade of pulmonary neuroendocrine carcinoma (NEC). We analyzed MFs by using a mitotic-specific antibody of phosphohistone H3 (PHH3) in 113 lung NECs (66 typical carcinoids [TCs], 12 atypical carcinoids [ACs], 20 large cell NECs [LCNECs], and 15 small cell lung carcinomas [SCLCs]). Subdivided by histologic subtype, the mean PHH3-stained MFs (mPHMFs) were 0.09 per high-power field (hpf) in TCs, 0.39/hpf in ACs, 7.84/hpf in LCNECs, and 9.42 in SCLCs. From the 5-year overall survival rate for mPHMFs, an mPHMF of more than 1.0 was the best threshold in all NECs and an mPHMF of more than 0.4 was the best threshold for differentiating ACs from TCs. These values correspond to 4/10 hpf and 10/10 hpf. We showed that the PHH3-based mitosis-counting method is a reliable, easy method for counting mitoses in pulmonary NECs.

Key Words:
  • Typical carcinoid
  • Atypical carcinoid
  • Large cell neuroendocrine carcinoma
  • Small cell carcinoma

Bronchopulmonary neuroendocrine carcinomas (NECs) constitute 20% of all lung carcinomas and represent a spectrum of tumors arising from neuroendocrine cells.1 Although all NECs share structural, morphologic, immunohistochemical, and ultrastructural features, they are separated into a 3-tier clinicopathologic spectrum of lung neoplasms with neuroendocrine differentiation: (1) well-differentiated (low-grade) NEC, which has a long life expectancy (typical carcinoid tumors [TCs]); (2) moderately differentiated (intermediate-grade) NECs with a more aggressive clinical course (atypical carcinoid tumors [ACs]), and (3) poorly differentiated (high-grade) NECs, which have a dismal prognosis (small cell lung carcinomas [SCLCs] and large cell NECs [LCNECs]).2,3

The grading of pulmonary NECs is based on the presence of necrosis and number of H&E-stained mitotic figures (HEMFs) at the hot spot. The thresholds of mitosis, as proposed by Travis et al,2 were adopted in the latest version of the World Health Organization (WHO) criteria as objective grading criteria: well-differentiated NECs exhibit fewer than 2 HEMFs per 10 high-power fields (hpf); moderately differentiated NECs exhibit 2 to 10 HEMFs per 10 hpf; and poorly differentiated NECs show 11 or more mitoses per 10 hpf. Furthermore, HEMFs have been shown to be one of the most reliable predictors of an unfavorable prognosis.46

However, the reliability and reproducibility of counting MFs in H&E-stained slides are limited by several factors, including selection bias of the hpf owing to subjective determination of the areas of highest mitotic activity and heterogeneity of mitotic activity in different areas of the tumor, thus requiring the experience of trained histopathologists.7,8 We recently reported the heterogeneous distribution of HEMFs in pulmonary carcinoid tumors.9 Furthermore, distinguishing MFs in H&E-stained slides from similar chromatin changes (ie, in apoptotic cells or secondary to crush, distortion, or karyorrhectic debris, pyknosis, or necrosis) is a subjective task. Identification of MFs could be facilitated by the use of mitosis-specific staining or labeling techniques.

In 1997, Hendzel et al10 introduced an antibody highly specific for the phosphorylated form of the amino terminus of histone H3 (Ser10), and immunohistochemical studies have documented a close correlation between phosphorylation on histone H3 and mitotic chromosome condensation initiating during the early prophase.11 These findings suggested that anti–phosphohistone H3 (PHH3) is a mitosis-specific marker. PHH3-based mitoses counting has proved to be a reliable and easy method for counting mitoses in various types of tumors.1219

Until now, no study has shown a correlation between PHH3-stained MFs (PHMFs) and survival in patients with pulmonary NECs. We evaluated the correlation between PHMFs and clinical outcomes and compared the results with those for HEMFs and the Ki-67 labeling index (LI). Although we previously analyzed the HEMFs in 80 well- to moderately differentiated pulmonary NECs,9 this new analysis is an update of our previous study and a reevaluation of some part of it; we have added cases of poorly differentiated NECs and the immunohistochemical analysis (PHH3 and Ki-67) of tumor proliferation.

Materials and Methods

Case Selection

We retrospectively reviewed tumor specimens from patients who were diagnosed with pulmonary NECs between 1990 and 2005. We obtained the specimens from cases deposited in the pathology files at the University of Texas M.D. Anderson Cancer Center, Houston. We obtained approval from the institutional review board to conduct the study. We reviewed the pathologic records of the specimens and all available H&E-stained slides, some slides with special stains, and the immunohistochemical and/or ultrastructural analyses available at that time.

Immunohistochemical Studies

After all H&E-stained slides were reviewed, the block was selected on 1 representative slide. For immunohistochemical staining, 4-μm-thick sections were deparaffinized. Heat-induced epitope retrieval was performed with Target Retrieval Solution High pH (DAKO, Carpinteria, CA) for PHH3 and Target Retrieval Solution (DAKO) for Ki-67. After the slides were cooled at room temperature for approximately 30 minutes, they were rinsed with deionized water. After that step, slides were treated with 3% hydrogen peroxide for 20 minutes to block endogenous peroxidase activity, followed by washing in deionized water for 2 to 3 minutes. The slides were then incubated with primary antibodies against PHH3 (Ser 10) (polyclonal, dilution 1:2,000; catalog No. 06–570, Upstate Cell Signaling Solutions, Lake Placid, NY) and Ki-67 (MIB1, dilution 1:100; DAKO) for 1 hour at room temperature. Immunoreactions were detected by using the EnVision+ Dual Link system (DAKO) and visualized with 3,3′-diaminobenzidine, followed by counterstaining with hematoxylin.

Histologic Evaluations

Mitoses were counted on 1 representative H&E- and PHH3-stained slide Image 1 each on an Olympus CX31 microscope (Olympus, Tokyo, Japan). This microscope’s standard field of view number is 20 (0.2 mm2); therefore, 1 hpf (×400) equals 0.2 mm2. We counted the number of mitoses and fields in the whole representative slide and then calculated the mean number of mitoses (the number of mitoses divided by the number of fields). We also recorded the highest number of mitoses per 1 field in each case.

Ki-67 immunoreactivity was used to evaluate positive nuclei of not only the highest labeling region (hot spot), but also the least labeling region (cold spot), which were initially selected under a 40× field. Subsequently, a 200× field was captured using the DP-70 system (Olympus) Image 2. Each captured slide was printed on letter-size paper using an Epson Stylus Photo R2880 Ink Jet Printer (Epson, Tokyo, Japan). The Ki-67 index of 1,000 tumor nuclei was counted. The Ki-67 index was expressed as a percentage of Ki-67+ nuclei compared with all counted tumor nuclei.

Image 1

Phosphohistone H3 immunostaining for poorly differentiated neuroendocrine carcinoma. Mitotic figures are easily recognizable (×40).

Image 2

Ki-67 cold and hot spots for well-differentiated neuroendocrine carcinoma. A, The cold spot of the Ki-67 index is 0.2%. B, The hot spot of the Ki-67 index is 1.4% (A and B, ×200).

Statistical Analysis

Statistical analysis was performed by using SPSS 12.0 for Windows (SPSS, Chicago, IL). The Tukey-Kramer test was used to perform multiple comparisons between groups for continuous variables, and the Kruskal-Wallis H test was used to compare categorical variables between groups. The Dunnett multiple comparison test was used to identify statistically significant differences between categorical data. Overall survival curves were calculated by using the Kaplan-Meier method. Curves were compared by using the log-rank test. The relationship among the number of HEMFs, PHMFs, and the Ki-67 index was investigated by using the Pearson correlation coefficient test. A P value of .05 or less was regarded as significant.

Results

Clinical Features

We reviewed tumor specimens from 129 patients with an original diagnosis of pulmonary NEC. We excluded the data for 14 patients who had received therapy preoperatively (13 who received neoadjuvant chemotherapy and 1 who received YAG laser ablation). The data for another 2 patients were excluded because the sections peeled during immunohistochemical studies. Therefore, our final cohort consisted of 113 cases of lung NECs, including 66 TCs, 12 ACs, 20 LCNECs, and 15 SCLCs. The mean follow-up time for all 113 patients was 61 months (range, 1–214 months), with 85 still alive at the time of this report.

Correlation Between Clinicopathologic Features and HEMFs

We reviewed 19 to 762 hpf per slide in each case. Because of massive necrosis, in some high-grade NECs we could not evaluate the abundance of fields of viable tumor cells. However, the mean hpf was 272.7. The total number of HEMFs ranged from 0 to 1,272 per slide, with an average of 129.4 and a median of 8.0 per slide. Subdivided by histologic subtype, the mean number of HEMFs (mHEMFs) was 0.024/hpf (range, 0.00–0.26) in TCs, 0.11/hpf (range, 0.01–0.32) in ACs, 2.97/hpf (range, 0.79–14.62) in LCNECs, and 1.82 (range, 0.42–5.36) in SCLCs Figure 1. Differences were statistically significant between TCs and LCNECs (P = .002), TCs and SCLCs (P < .0001), ACs and LCNECs (P = .003), and ACs and SCLCs (P < .0001).

Thresholds for HEMFs

To determine the thresholds of mHEMFs for patient outcome, we analyzed the following mHEMF values in all NECs: more than 0.1, 0.2, 0.4, 1.0, and 2.0. The 5-year overall survival rate for mHEMFs was 41.0% for more than 0.1 and 98.5% for 0.1 or less (P < .0001); 37.2% for more than 0.2 and 98.6% for 0.2 or less (P < .0001); 36.5% for more than 0.4 and 94.4% for 0.4 or less (P < .0001); 36.4% for more than 1.0 and 92.2% for 1.0 or less (P < .0001); and 52.6% for more than 2.0 and 80.1% for 2.0 or less (P = .0008). Therefore, an mHEMF value of more than 1.0 was the best threshold for all NECs.

Figure 1

The mean number of mitoses subdivided by histologic type. AC, atypical carcinoid; HEMF, H&E-stained mitotic figures; hpf, high-power field; LCNEC, large cell neuroendocrine carcinoma; PHMF, phosphohistone H3–stained mitotic figures; SCLC, small cell lung carcinoma; TC, typical carcinoid.

We also analyzed the following mHEMF values for TCs and ACs: more than 0.1, 0.2, 0.3, and 0.4. The 5-year overall survival rate for mHEMFs was 57.1% for more than 0.1 and 98.5% for 0.1 or less (P < .0001); 37.8% for more than 0.2 and 98.6% for 0.2 or less (P < .0001); 0% for more than 0.3 and 96.9% for 0.3 or less (P = .0001); 36.4% for more than 1.0 and 92.2% for 1.0 or less (P < .0001); and 52.6% for more than 2.0 and 80.1% for 2.0 or less (P = .0008). Therefore, an mHEMF value of more than 0.2 was the best threshold for differentiating ACs from TCs.

Correlation With Clinicopathologic Features and PHMFs

We reviewed 33 to 634 hpf per slide in each case. Because of massive necrosis, in some high-grade NECs we could not evaluate the abundance of fields of viable tumor cells. However, the mean number of hpf was 241.9. The number of PHMFs ranged from 0 to 4,189, with an average of 429.2 and a median value of 39.0 per case. Subdivided by histologic subtype, the mean PHMF (mPHMF) was 0.09/hpf (range, 0.00–0.62) in TCs, 0.39/hpf (range, 0.02–1.14) in ACs, 7.84/hpf (range, 2.08–18.23) in LCNECs, and 9.42 (range, 2.97–14.14) in SCLCs (Figure 1). Differences were statistically significant between TCs and LCNECs (P < .0001), TCs and SCLCs (P < .0001), ACs and LCNECs (P = .003), and ACs and SCLCs (P < .0001).

Thresholds for PHMFs

To determine the thresholds of mPHMF for patient outcome, we analyzed the following mPHMF values in all NECs: more than 0.1, 0.2, 0.4, 1.0, and 2.0. The 5-year overall survival rates for mPHMFs were 56.1% for more than 0.1 and 98.0% for 0.1 or less (P < .0001); 46.5% for more than 0.2 and 98.4% for 0.2 or less (P < .0001); 37.9% for more than 0.4 and 98.5% for 0.4 or less (P < .0001); 36.3% for more than 1.0 and 96.1% for 1.0 or less (P < .0001); and 36.5% for more than 2.0 and 94.4% for 2.0 or less (P < .0001). Therefore, an mPHMF value of more than 1.0 was the best threshold for all NECs Figure 2A.

We also analyzed the following mPHMF values in TCs and ACs: more than 0.1, 0.2, 0.3, and 0.4. The 5-year overall survival rates for mPHMFs were 85.0% for more than 0.1 and 98.0% for 0.1 or less (P = .131); 68.0% for more than 0.2 and 98.4% for 0.2 or less (P = .012); 41.7% for more than 0.3 and 98.5% for 0.3 or less (P < .0001); and 0% for more than 0.4 and 98.6% for 0.4 or less (P < .0001). Therefore, an mPHMF value of more than 0.4 was the best threshold for differentiating ACs from TCs Figure 2B.

Highest Number of HEMFs and PHMFs in 1 HPF

The mean of the highest number of HEMFs in 1 hpf was 3.9 (range, 0–35) in all NECs. Subdivided by histologic subtype, the mean of the highest number of mitoses in 1 hpf was 1.2/hpf (range, 0–5) in TCs, 1.8/hpf (range, 1–3) in ACs, 11/hpf (range, 3–35) in LCNECs, and 8.5 (range, 3–25) in SCLCs. The mean of the highest number of PHMFs in 1 hpf was 9.3 (range, 0–64) in all NECs. Subdivided by histologic subtype, the mean of the highest number of mitoses in 1 hpf was 1.6/hpf (range, 0–5) in TCs, 3.0/hpf (range, 1–6) in ACs, 23.3/hpf (range, 9–61) in LCNECs, and 29.4 (range, 7–64) in SCLCs.

Correlation Between Histologic Subtype and the Ki-67 Index

Cold Spot of Ki-67 LI

The mean Ki-67 index in the cold spot (cKi-67) was 10.5% (range, 0%–56.1%). Subdivided by histologic subtype, the mean cKi-67 index in the cold spot was 0.1% (range, 0%–1.3%) in TCs, 0.7% (range, 0%–2.2%) in ACs, 36.8% (range, 12.5%–56.1%) in LCNECs, and 29.0% (range, 3.1%–53.5%) in SCLCs Figure 3. Differences were statistically significant between TCs and LCNECs (P < .0001), TCs and SCLCs (P < .0001), ACs and LCNECs (P < .0001), and ACs and SCLCs (P < .0001).

Hot Spot of the Ki-67 LI

There were no statistical differences in the number of nuclei counted between the cold and hot spots. The mean Ki-67 index in the hot spot (hKi-67) was 19.1% (range, 0.1%–90.5%). Subdivided by histologic subtype, the mean hKi-67 index in the hot spot was 2.0% (range, 0.1%–9.5%) in TCs, 7.2% (range, 0.8%–21.9%) in ACs, 55.9% (range, 32.0%–90.5%) in LCNECs, and 53.6% (range, 31.3%–77.4%) in SCLCs (Figure 3). Differences were statistically significant between TCs and LCNECs (P < .0001), TCs and SCLCs (P < .0001), ACs and LCNECs (P < .0001), and ACs and SCLCs (P < .0001).

Figure 2

Five-year overall survival analysis. A, Mean number of phosphohistone H3 mitotic figures >1.0 (solid line) and ≤1.0 (dashed line). The 5-year overall survival rates were 96.1% and 36.3% in all neuroendocrine carcinomas (P < .0001). B, Mean number of phosphohistone H3 mitotic figures >0.4 (solid line) and ≤0.4 (dashed line). The 5-year overall survival rates were 98.0% and 0% in well- and moderately differentiated neuroendocrine carcinomas, respectively (P < .0001).

Correlations Among mHEMFs, mPHMFs, and the hKi-67 LI

In all NECs, a statistically significant (P < .0001) strong correlation (γ = 0.92) was observed between the HEMFs and PHMFs. The mPHMF was 3.25 times higher than the mHEMF. When we analyzed TCs and ACs, a statistically significant (P < .0001) strong correlation (γ = 0.899) was observed between the HEMFs and PHMFs. The mPHMF was 3.5 times higher than the mHEMF. For poorly differentiated NECs, a statistically significant (P < .0001) moderate correlation (γ = 0.595) was observed between the HEMFs and PHMFs. The mPHMF was 1.9 times higher than the mHEMF.

A statistically significant (P < .0001) moderate correlation (γ = 0.629) was observed between mHEMFs and the hKi-67 index. A statistically significant (P < .0001) strong correlation (γ = 0.747) was also observed between the mPHMF and hKi-67 index.

Figure 3

Distribution of the Ki-67 index subdivided by histologic type. The blue line indicates the cold spot of Ki-67, and the red line indicates the hot spot of Ki-67. The diamond boxes indicate each mean value of Ki-67. The gray area indicates indeterminate neuroendocrine carcinoma. AC, atypical carcinoid; LCNEC, large cell neuroendocrine carcinoma; SCLC, small cell lung carcinoma; TC, typical carcinoid.

Proposing the Ki-67 LI Threshold for Small Biopsy Materials

To detect the threshold of the Ki-67 LI, we analyzed the Ki-67 LI in conjunction with the cKi-67 and hKi-67. The lowest cKi-67 index in poorly differentiated NECs was 3.1%. The highest hKi-67 index in well- to moderately differentiated NECs was 21.9%. The mean hKi-67 indexes in well- and moderately differentiated NECs were 2.0% and 7.2%, respectively. From these data, we determined that a Ki-67 index of less than 3% indicated well-differentiated NEC and more than 30% indicated poorly differentiated NEC (Figure 3). Thus, a Ki-67 index between 3% and 30% indicates indeterminate NECs that mostly consist of moderately differentiated NECs, albeit some poorly differentiated NECs are also included.

Discussion

Counting MFs with the assistance of PHH3 immunostaining is a more sensitive method for detecting MFs than the traditional method of counting HEMFs. The number of mPHMFs was 3.25 times higher than the number of mHEMFs in all NECs that we analyzed. When we used mPHMFs instead of mHEMFs, the mitotic thresholds between well- and moderately differentiated NECs increased to 0.4 from 0.2, but this finding was not seen in poorly differentiated NECs. These data correspond to 4/10 hpf and 10/10 hpf, respectively, in contrast with the latest WHO criteria. These results indicate that the mitotic thresholds based on HEMFs should not be applied to PHMFs without verification by PHMF immunostaining.

The threshold of PHMFs for poorly differentiated NEC did not change in comparison with well- and moderately differentiated NECs. One important issue was that we previously used mean MF counting instead of evaluating MF in mitotically active 10 hpf, because HEMFs were heterogeneously distributed in well- to moderately differentiated NECs.9 Thus, we also applied this counting method for PHMFs. The MFs in poorly differentiated NECs show comparatively homogenous distribution, and the mean mitotic count is of less diagnostic value in poorly differentiated NECs compared with well- and moderately differentiated NECs.

Although the highest number of PHMFs in 1 hpf of 2 indicates moderately or poorly differentiated NEC according to the latest WHO criteria, which are based on HEMFs, 29 (44%) of 66 cases of well-differentiated NECs had the highest number of PHMFs in 1 hpf of 2 or more. We previously reported similar data in HEMFs and cautioned pathologists to evaluate only at the hot spot.9 Other studies have reported similar disparities between PHMFs and HEMFs: In meningiomas, 10.6% to 17% of cases have a higher WHO grade when PHMFs are used.12,15 These results suggest that as more pathologists correctly recognize MFs in H&E-stained slides, a higher grade is diagnosed more frequently. Therefore, these results indicate that the latest WHO criteria for diagnosing moderately differentiated pulmonary NEC are strict only in evaluating MF in mitotically active 10 hpf.

We found that the correlation between HEMFs and PHMFs was higher in well- and moderately differentiated NECs (γ = 0.899) than in poorly differentiated NECs (γ = 0.595). One possible reason for this correlation is that the presence of apoptotic cells or damage secondary to crushing, distortion, karyorrhectic debris, pyknosis, or necrosis hides the true MFs in HEMF slides, especially for high-grade NECs. The greatest differences between HEMFs and PHMFs were found in more actively proliferating areas in uveal melanoma19 and higher grade tumors of breast adenocarcinoma.20 An advantage of PHMFs over HEMFs is that the MFs in PHMFs can be distinguished clearly and unambiguously. In accordance with previous studies,13,15,20,21 we were able to detect MFs quickly and easily. Thus, PHMF counting is a rapid, easy, and sensitive method for the assessment of mitotic activity.

Previous studies have demonstrated a strong correlation between the proliferative index, as detected by the Ki-67 LI, and tumor grade and prognosis.2233 In the articles in which Ki-67 LIs were stated numerically, most moderately differentiated NECs had a proliferative index of less than 25%, most well-differentiated NECs had an index of less than 10%, and most SCLCs had an index of substantially more than 25%.22,23,25,26,29,31,32 Other reports revealed that PHMFs were closely correlated with the Ki-67 LI.14,21 In addition, we revealed that PHMFs were more closely correlated with the Ki-67 LI (γ = 0.747) than were HEMFs (γ = 0.629). Compared with PHH3, which reacts only with cells in the M phase, Ki-67 antibody reacts with cells in the G1, S, G2, and M phases.34 These data also demonstrated that PHMFs are superior to HEMFs for measuring mitotic activity.

In the present study, we found that PHMFs were more useful and reliable than HEMFs for counting MFs. However, when grading small biopsy samples of pulmonary NECs, this method has some limitations because crush artifact is a characteristic feature of NECs, especially SCLCs.35 We occasionally observed PHH3 immunostaining in crushed nuclei but were not able to differentiate whether this was true-positive or nonspecific staining (data not shown). Frequently, forceps biopsy specimens accompanied these artifacts. For this type of sample, Ki-67 immunostaining has been reported as a reliable marker for determining proliferation activity.36

For small biopsy samples, it is impossible to know whether the samples were evaluated by hot spots or something else. Thus, we analyzed the Ki-67 data in conjunction with cold and hot spots and propose use of the following criteria: a Ki-67 index less than 3% indicates well-differentiated NEC, 3% to 30% indicates indeterminate NEC, and more than 30% indicates poorly differentiated NEC. Because cases of indeterminate NEC mostly consist of moderately differentiated NEC (albeit some poorly differentiated NECs are included), such cases require close follow-up or rebiopsy after multidisciplinary analysis. Other studies have also reported the usefulness of the Ki-67 index in assessing biopsy material,36,37 suggesting cutoff values of less than 20% for carcinoid tumors and more than 25% for SCLCs. Although current WHO histologic criteria focus on surgically resected materials, most patients with lung carcinoma have advanced disease that cannot be resected at the initial diagnosis.38 Establishment of diagnostic criteria for small biopsy specimens is needed. Although the differential diagnosis between carcinoid tumors and SCLCs is based on cytomorphologic features, these data indicate that the Ki-67 LI supports the exact diagnosis in small biopsy samples.

We showed that PHH3-based mitoses counting is a reliable and easy method for counting mitoses in pulmonary NECs. By using the mPHMF, the mitotic threshold between well- and moderately differentiated NECs was 0.4 and that for poorly differentiated NECs was 1.0; these values correspond to 4/10 hpf and 10/10 hpf. We also propose a threshold for the Ki-67 LI for diagnosing pulmonary NECs in small biopsy samples: less than 3% for well-differentiated NECs, 3% to 30% for indeterminate NECs, and more than 30% for poorly differentiated NECs.

CME/SAM

Upon completion of this activity you will be able to:

  • define the mean mitotic count threshold that assists in separating atypical carcinoids from typical carcinoids of the lung and the mean mitotic count threshold for poorly differentiated neuroendocrine carcinomas of the lung.

  • identify the cell cycles that are identified by antibodies against anti–phosphohistone H3 and Ki-67.

  • list possible limitations of H&E estimates of mitotic index and advantages of immunohistochemistry using immunohistochemistry for anti–phosphohistone H3.

The ASCP is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASCP designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit ™ per article. Physicians should claim only the credit commensurate with the extent of their participation in the activity. This activity qualifies as an American Board of Pathology Maintenance of Certification Part II Self-Assessment Module.

The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

Questions appear on p 331. Exam is located at www.ascp.org/ajcpcme.

Acknowledgments

We thank Susan Cweren and Denise Woods for skillful technical assistance and the Department of Scientific Publications, M.D. Anderson Cancer Center, for skillful English editing.

Footnotes

  • Supported in part by grant PROSPECT W81XWH-07-1-0306 from the US Department of Defense.

References

  1. 1.
  2. 2.
  3. 3.
  4. 4.
  5. 5.
  6. 6.
  7. 7.
  8. 8.
  9. 9.
  10. 10.
  11. 11.
  12. 12.
  13. 13.
  14. 14.
  15. 15.
  16. 16.
  17. 17.
  18. 18.
  19. 19.
  20. 20.
  21. 21.
  22. 22.
  23. 23.
  24. 24.
  25. 25.
  26. 26.
  27. 27.
  28. 28.
  29. 29.
  30. 30.
  31. 31.
  32. 32.
  33. 33.
  34. 34.
  35. 35.
  36. 36.
  37. 37.
  38. 38.
View Abstract