Phosphohistone-H3 and Ki-67 immunostaining in cutaneous pilar leiomyoma and leiomyosarcoma (atypical intradermal smooth muscle neoplasm)

Expanding the Spectrum of Perioral Myogenic Tumors in Pediatric Patients: An SRF::NCOA2 Fused Perivascular Tumor of the Philtrum

BACKGROUND

Perivascular tumors, which include myopericytoma and myofibroma, are rare benign soft tissue neoplasms composed of perivascular smooth muscle cells. Most demonstrate characteristic morphology and are readily diagnosed. However, a recently identified hypercellular subset shows atypical histologic features and harbor unique SRF gene fusions. These cellular perivascular tumors can mimic other more common sarcomas with myogenic differentiation.

METHODS

Clinical, radiological, morphological, immunohistochemical, and molecular findings were reviewed.

RESULTS

A slow-growing, fluctuant mass was noted within the philtrum at 16 months. Ultrasonography revealed a well-circumscribed cystic hypoechoic lesion. A small (1.0 cm), tan, well-circumscribed soft-tissue mass was excised after continued growth. Histologically, the encapsulated tumor was hypercellular and composed of spindle cells with predominantly-storiform architecture, focal perivascular condensation, dilated branching thin-walled vessels, increased mitoses, and a smooth muscle immunophenotype. An SRF::NCOA2 fusion was identified.

CONCLUSION

We report the first case of an SRF-rearranged cellular myopericytoma in the perioral region in a young child. This case expands the differential diagnosis of perioral soft tissue tumors with myogenic differentiation. We highlight key clinical, pathological, and molecular features. As we illustrate, these rare tumors pose a considerable diagnostic challenge, and risk misdiagnosis as sarcoma, most notably spindle cell rhabdomyosarcoma.

Leiomyoma with Bizarre Nuclei: A Current Update

Leiomyoma with bizarre nuclei (LBN), also known as symplastic leiomyoma, is a histological subtype of benign leiomyoma with bizarre cells and nuclear atypia. Differentiating LBN from other benign leiomyoma subtypes, uterine smooth muscle tumors of uncertain malignant potential (STUMP), or leiomyosarcoma (LMS) can be diagnostically challenging owing to overlapping features in clinical presentation and pathologic morphological analysis. The difficulty of distinguishing LBN from other lesions, especially from LMS, and the potential of LBN for subsequent malignant transformation make LBN an important topic of research. Herein, we review the definition, diagnosis, treatment, and prognosis of LBN. Histopathological examination is essential for distinguishing LBN from other diseases. Pathology sampling and morphological examination remain the key to diagnosis. The newly established ancillary immunohistochemical (IHC) and molecular genetic analysis can be useful tools for differential diagnosis. Furthermore, serum biomarkers and imaging examination may also be useful diagnostic tools. Attention should be paid to the differentiation between LBN and LMS because morphological diagnosis may still be challenging in some cases. Some IHC markers of LBN have been identified, which may be helpful for differential diagnosis. Furthermore, the use of IHC panels as diagnostic markers may be advocated. Molecular genetic studies suggest that some genes can aid with the differential diagnosis between LBN and LMS. However, increasing evidence support the idea that LBN and LMS are molecularly related, indicating that LBN may represent a potentially malignant stage of precancerous progression. At present, conservative treatment is recommended for primary LBN, especially for patients desiring to retain fertility, but close follow-up with imaging examinations is required.

Piloleiomyoma Presented by Multiple Cutaneous Nodules: a Case Report

Introduction. Piloleiomyoma is a rare benign tumor which is caused by erector pili muscle and makes up 5% of all leiomyomas. They can be solitary and multiple. Multiple lesions still pose challenges for clinicians since their treatment option is very limited.

Case report. We report a case of a 25-year-old male patient who had painful papules and nodules on the neck and chest for three years. Multiple red-brown papules and nodules in the skin of regio mammaria dextra and regio submandibularis on the left were seen on physical examination. Histopathological examination of punch bi-were seen on physical examination. Histopathological examination of punch biopsy sample revealed well-circumscribed nodule composed of spindle cells. The case was reported as cutaneous leiomyoma (piloleiomyoma). The patient was given 5 mg/day amlodipin and kept under control.

Conclusion. The ideal treatment option for piloleiomyoma is surgical excision, but the problem with that treatment is that the lesions have tendency to recur. Medicamentous therapy plays a limited role; however, calcium-channel blockers and α-adrenergic blockers may help in palliating or eliminating associated pain through inhibition of smooth muscle contraction.

Leiomyosarcoma of the skin: review of the literature with an emphasis on prognosis and management

Leiomyosarcoma (LMS) of the skin is rare, and no management guideline currently exists. Although LMS is historically classified as either dermal (cutaneous) or subcutaneous, definition for its classfication is inconsistent in the literature. Studies on the managenent of LMS are scarce, and there is no consensus on the appropriate surgical margin for the treatment of LMS. While a 1 cm margin may be sufficient in cutaneous LMS, wider margins may be required for subcutaneous tumors. Mohs micrographic surgery is a promising surgical modality for the treatment of cutaneous LMS. In this review, current knowledge on LMS is summarized and a practical approach to the management of this rare neoplasm is proposed.

Human mesenchymal stem cells promote tumor growth via MAPK pathway and metastasis by epithelial mesenchymal transition and integrin α5 in hepatocellular carcinoma

Mesenchymal stem cells (MSCs) appear to be a potential vehicle for anticancer drugs due to their excellent tumor tropism ability. However, the interactions between MSCs and hepatocellular carcinoma (HCC) are quite controversial and the underlying mechanisms are ambiguous. In this study, an investigation was conducted into the effect of human MSCs (hMSCs) on tumor proliferation and metastasis both in xenograft and orthotopic models. It was discovered that hMSCs could promote tumor growth though activating mitogen-activated protein kinase (MAPK) signaling pathway and promote metastasis by epithelial mesenchymal transition (EMT) in vivo. To test whether hMSCs could induce immunosuppressive effects, the expression of the Natural killer (NK) cell marker CD56 was measured by immunohistochemical staining and the expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured by qRT-PCR. It was found out that CD56 expression significantly decreased, while TNF-α and IL-6 expression increased in the hMSCs-treated tissues. Mechanistically, RNA sequencing was performed, which led to a discovery that integrin α5 (ITGA5) was over-expressed in hMSCs-treated HCC. ITGA5 siRNAs blocked the hMSCs-induced migration and invasion of HCC, while over-expression of ITGA5 promoted the migration and invasion ability in HCC-hMSCs, indicating that the expression of ITGA5 is associated with hMSCs-induced tumor metastasis. These findings suggest that hMSCs may play a vital role in HCC proliferation and metastasis and could be identified as a putative therapeutic target in HCC.

Cutaneous Smooth Muscle Tumors: A Review

Smooth muscle tumors occur infrequently in the skin. They consist of a diverse group of lesions representing hamartomas as well as benign and malignant neoplasms. They may arise from arrector pili muscle, specialized smooth muscle of the genitalia, or vascular smooth muscle. Although rare, accurate diagnosis and classification of cutaneous smooth muscle proliferations is important as they can exhibit a range of clinical behavior and may be associated with underlying syndromes. This review summarizes the clinicopathologic spectrum of smooth muscle tumors involving the skin.

Phosphohistone-H3 and Ki67: Useful Markers in Differentiating Dermatofibroma From Dermatofibrosarcoma Protuberans and Atypical Fibrohistiocytic Lesions

Dermatofibromas (DF) are common, benign, skin tumors, usually easily differentiated from dermatofibrosarcoma protuberans (DFSP) by the presence of a relative low cellularity, lesser degree of infiltration of subcutaneous tissue, and immunohistochemical pattern (eg, FXIIIa in DF and CD34 in DFSP). Atypical fibrohistiocytic lesions (AFL) have features intermediate to DF and DFSP (trunk location, storiform pattern, infiltration of the subcutaneous tissue, and focal expression of both CD34 and Factor XIIIa). It is unclear if mitotic counts/degree of proliferation is helpful to distinguish DF from DFSP. To study the mitotic rate and proliferation index in DF, AFL/DFSP, anti-ki67, and anti-PHH3 were performed on 10 cases of DF (including 4 cellular DF), 10 standard DFSP, and 2 AFL. The proliferation index and mitotic figures were counted per square millimeter in a "hotspot" (in a fashion similar to mitotic counts in melanoma). All cases of DF showed much higher Ki67 proliferation index (P = 0.0001) along with increased mitotic figures both on H&E and with anti-PHH3 (P = 0.0001) when compared to AFL/DFSP. Our data indicate that DF has a higher proliferation index and mitotic counts when compared to superficial/peripheral portion of AFL and DFSP. This finding may be helpful in the differential diagnosis among these fibrohistiocytic lesions.

The mitosis-specific marker phosphohistone-H3 (PHH3) is an independent prognosticator in uterine smooth muscle tumours: an outcome-based study

AIMS

Accurate mitosis counting, which is important in the diagnosis of uterine smooth muscle tumours (USMTs), is often difficult and subjective. The mitosis-specific immunohistochemical marker phosphohistone-H3 (PHH3) has been shown to be diagnostically useful, but its expression, in relation to outcome, has not been thoroughly investigated. The aim of this study is to evaluate PHH3 as a diagnostic and prognostic marker in USMTs.

METHODS AND RESULTS

PHH3 expression was evaluated in 55 leiomyosarcomas (LMSs), 26 smooth muscle tumours of uncertain malignant potential (STUMPs), 18 leiomyomas with bizarre nuclei (LBN), and 12 leiomyomas (LMs). Scores were expressed as counts per 10 high-power fields (HPFs). Median follow-up durations of patients with LMS, STUMP, LBN and LM were, respectively, 39, 78, 65.5 and 49.5 months. Twenty-eight patients with LMSs (50.9%) died, and two (7.7%) patients with STUMPs experienced recurrence. The median PHH3 scores for LMSs were significantly higher than those for other categories of tumour. A score of ≥29/10 HPFs was also independently associated with a poor outcome. To test whether the PHH3 score could distinguish between benign USMTs with atypical histology and those that were clinically malignant, two biological groups were further delineated. Patients in group 1 (18 LBNs and 24 STUMPs) all had an uneventful outcome, whereas patients in group 2 (two recurrent STUMPs and 32 LMSs) all had a recurrence or tumour-related death. Median PHH3 scores for the two groups were, respectively, 2/10 HPFs and 27/10 HPFs. A PHH3 score of ≥7/10 HPFs was highly associated with malignancy.

CONCLUSION

PHH3 is useful in evaluation of the biological behaviour of USMTs, and may serve as a prognostic indicator for LMSs.

Phosphohistone-H3 Proliferation Index Is Superior to Mitotic Index and MIB-1 Expression as a Predictor of Recurrence in Human Meningiomas

OBJECTIVES

This study investigated the prognostic value of the phosphohistone-H3 (PHH3) proliferation index (PI) in human meningiomas and compared the reliability with the conventional mitotic index and MIB-1 biomarker.

METHODS

Proliferative activity was determined in 160 patients by standardized immunohistochemistry on tissue microarrays and related to recurrence.

RESULTS

All three proliferation assessment methods were significantly associated with World Health Organization grade. The optimal cutoff values for recurrence prediction were 3% for the MIB-1 PI and 0.5% for the PHH3 PI. Increased PHH3 PI was significantly associated with recurrence-free survival in univariate Cox proportional hazards regression analysis (P = .011) and remained an independent predictor in multivariate analysis (P = .005). Mitotic index and MIB-1 PI did not reach statistical significance.

CONCLUSIONS

PHH3 immunostaining allowed for the easiest, fastest, and most objective assessment of proliferation and proved to be the most accurate and reliable method for predicting recurrence in patients resected for meningiomas.

Phosphohistone H3 expression correlates with manual mitotic counts and aids in identification of "hot spots" in fibroepithelial tumors of the breast

Classification of mammary fibroepithelial tumors (FETs) relies on assessment of mitotic activity, among other histopathologic parameters. Routine hematoxylin and eosin (H&E) mitotic counts can be subjective and time consuming. Difficulty may arise in identifying "true" mitoses for a variety of reasons. Phosphorylation of histone H3 protein (PHH3) is correlated with mitotic chromatin condensation. The utility of PHH3 immunohistochemical staining to identify mitoses has been demonstrated in multiple organ systems. In this study, we examined the utility of PHH3 in assessing mitotic activity in FETs and compared PHH3- with H&E-determined mitotic counts. PHH3-stained mitoses were readily identifiable at ×10 magnification and allowed for rapid identification of mitotic "hot spots." Median mitotic counts/10 high-power fields for fibroadenoma, benign phyllodes tumor, borderline phyllodes tumor (BlnPT), and malignant phyllodes tumor (MPT) were 0, 0.5, 4.25, and 9, respectively on H&E, and 0, 0.75, 4.5, and 8, respectively for PHH3. Among all FETs, there was a strong positive correlation between H&E- and PHH3-determined mitotic counts (r=0.91, P<.001). Using PHH3, 2 cases would be reclassified, both from BlnPT to MPT. PHH3-determined counts correlated with H&E-determined counts in FETs. Using PHH3, a small number of cases were reclassified from BlnPT to MPT, for which treatment is similar. Although H&E-determined counts remain the criterion standard for assessing mitotic activity in FETs, PHH3 may be a useful adjunctive tool in some cases and is helpful in identifying mitotic hot spots.

Immunostaining of phospho-histone H3 and Ki-67 improves reproducibility of recurrence risk assessment of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common non-epithelial tumors in the digestive tract. Beyond surgery, therapeutic management depends on risk of recurrence. Risk evaluation of GIST takes into account location and size of the tumor, whether or not the tumor was intact or ruptured and mitotic index. The mitotic index lacks in intra- and interobserver reproducibility. In this study, we evaluated on 61 GISTs, the reproducibility of mitotic counting using classical hematoxylin-eosin-saffron (HES) staining, and its correlation with the mitotic count obtained through immunohistochemical staining for phospho-histone H3 (PHH3) and the proliferation index based upon Ki-67 immunostaining. Mitotic counts by HES and PHH3 staining and Ki-67 proliferation index were evaluated twice by three independent observers taking into account interpretation times per tumor for each technique. HES-based and PHH3-based mitotic counts and Ki-67 proliferation index correlated well and presented good intra- and interobserver reproducibility. PHH3 staining resulted in a slight but statistically significant difference of about two more mitotic figures per 5 mm(2) than the HES-based count, which might have put some borderline tumors in a different risk category. Immunohistochemical staining for PHH3 and Ki-67 allowed more rapid interpretation than mitotic counts based upon HES staining, but only PHH3 staining allows counting of mitoses. Immunostaining using anti-PHH3 and anti-Ki-67 antibodies will eventually provide improved recurrence risk stratification of GIST and may become effective ancillary tools in deciding on optimal therapeutic management.

Better see to better agree: phosphohistone H3 increases interobserver agreement in mitotic count for meningioma grading and imposes new specific thresholds

BACKGROUND

Mitotic count on hematoxylin and eosin (H&E)-stained slides is a crucial diagnostic criterion in meningioma grading. However, mitosis assessment on H&E slides can be impaired by technical factors and by pathologist's experience. Phosphohistone H3 (PHH3) serine-10 is a mitosis-specific antibody that has proven to facilitate mitotic count in various tumors.

METHODS

A series of 70 meningiomas (15 grade I, 40 grade II, 15 grade III) was used to validate PHH3 intra- and interobserver reproducibility and to identify PHH3-specific mitotic thresholds. Four pathologists with different experience in neuropathology counted mitoses on both H&E- and PHH3-stained slides.

RESULTS

H&E and PHH3 mitotic rates were highly correlated (Pearson's r = 0.92, P < .0001). PHH3 mitotic counts had both a good mean interobserver correlation (R(m) = 0.83) and a good intraclass correlation (0.78), higher than H&E mitotic indices (R(m) = 0.77, intraclass correlation = 0.71). After further stratification of meningiomas according to World Health Organization grade, PHH3 performed better in terms of interobserver concordance (Kendall's W = 0.761) compared with H&E (Kendall's W = 0.697). Referring to the same meningioma groups identified by World Health Organization grade as the gold standard, the volume under the receiver operator characteristic surface was 0.91, indicating a very good diagnostic ability of PHH3 scores in discriminating the 3 meningioma groups. The 2 optimal PHH3-specific cutoff values were 6.61 and 22.02.

CONCLUSION

PHH3 staining is a useful diagnostic complementary tool to standard H&E mitotic count, optimizing intra- and interobserver reproducibility. PHH3-specific mitotic thresholds should be adopted to avoid overgrading of meningioma when ancillary methods are employed.

G protein-coupled estrogen receptor 1 (GPER 1) mediates estrogen-induced, proliferation of leiomyoma cells

G protein-coupled estrogen receptor 1 (GPER-1, formerly known as GPR30) has been proposed as the receptor for estrogen-induced, growth of leiomyomas though its precise mechanisms of action are not clear. We obtained leiomyoma cells (LC) and normal smooth muscle cells from 28 women (n = 28, median age 38 years, median parity 1.0). We incubated them with 17-β estradiol (E(2)), after blocking, or upregulating, expression of GPER-1 with ICI182,780 (a GPER-1 agonist) and siGPR30, respectively. We evaluated the role of GPER-1 in the mitogen-activated protein kinase (MAPK) signaling pathway using Western blot analysis. We studied cell proliferation with 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide, and, mitotic activity with phosphohistone H3 (PPH3) expression in leiomyoma, and, matched, normal, smooth muscle tissues using standard immunohistochemistry. Downregulation of GPER-1 expression with siGPR30 partially attenuated the E(2)-activated MAPK signaling pathway (p < 0.01). Upregulation of GPER-1 with ICI182,780 enhanced the E(2)-activated MAPK signaling pathway (p < 0.01). ICI182,780 enhanced E(2)-induced proliferation of LC (p < 0.01), while knock down of the GPER-1 gene with GPER-1 small interfering RNA partially inhibited E(2)-induced cell proliferation (p < 0.01). There were no significant differences in PPH3 expression between LCs and normal smooth muscle tissues (p > 0.05). Neither ICI182,780 nor siGPR30 increased mitosis in LCs (p > 0.05). Our results indicate that GPER-1 mediates proliferation of estrogen-induced, LC by activating the MAPK pathway, and, not by promoting mitosis.

Immunostaining analysis of tissue cultured cells and tissue sections using phospho-Histone H3 (Serine 10) antibody

Post-translational modifications of histones play an important role in regulation of gene expression through condensation and decondensation of chromatin structure. These modifications include acetylation, methylation, phosphorylation and ubiquitination. Phosphorylation on histones is associated with cellular responses such as DNA damage, transcription, chromatin compaction and mitosis or meiosis. One of the most extensively studied modifications of histones is the Serine 10 phosphorylation on histone H3 N-terminal tail. This specific phosphorylation on Histone H3 has been associated with condensation and transcriptional inactivation of mitotic chromosomes, but recent studies have suggested a role for this specific phosphorylation in chromatin relaxation and activation of transcription in interphase cells. Co-immunostaining analysis of cells using antibodies specific to serine 10P-Histone H3 together with those to cell cycle specific markers will allow us to determine the nature of phosphorylation in a cell cycle-specific manner. In a complex system, such as tissue specimens, analysis using P-Histone H3 and a cell type specific antibody will allow identification of specific cells that are affected by this histone modification. This is of particular interest in the field of cancer biology or neurobiology where identification or quantification of the transcriptionally active or mitotic cells will enable one to evaluate the progression of the disease development. The protocol described here provides details on how co-immunostaining and analysis can be performed in tissue cultured cells or tissue sections.

Symplastic leiomyomas of the scrotum: a comparative study to usual leiomyomas and leiomyosarcomas

Smooth muscle tumors of the scrotum are very uncommon, and those with degenerative-appearing atypia, variably designated as "atypical," "symplastic," or "bizarre" leiomyomas, are extremely rare with only 11 cases in the literature. Given their rarity, the diagnostic criteria and prognosis of symplastic leiomyomas are not well established. We describe 9 cases of scrotal symplastic leiomyomas and compare their histopathologic characteristics to 10 usual leiomyomas and 5 leiomyosarcomas of the scrotum. The preoperative diagnosis was scrotal tumor or cyst in all cases. The mean age was 46 years (range, 32 to 60 y) for usual, 59 (range, 48 to 79) for symplastic leiomyomas, and 57 (range, 49 to 65) for leiomyosarcoma. Submitting diagnoses for symplastic leiomyomas were: atypical spindle cell lesion (n=3); probably leiomyosarcoma (n=1); leiomyosarcoma (n=1); and none given (n=4). Symplastic leiomyomas were diagnosed when there was moderate-severe cytologic atypia, yet was degenerative-appearing with multinucleation or smudged chromatin in the setting of low nuclear/cytoplasmic ratio, low cellularity, and no mitotic activity. The mean size was 1.0 cm for usual leiomyomas, 1.0 cm for symplastic leiomyomas, and 2.0 cm for leiomyosarcomas. Leiomyosarcomas had high nuclear/cytoplasmic ratio, high cellularity, nuclear pleomorphism, and hyperchromasia. Five of 10 usual and 3/9 symplastic leiomyomas showed at least 1 ill-defined border simulating infiltrative growth. Three leiomyosarcomas were grade 1, and 2/5 were grade 2. Resection margins were positive in 5/10 usual and 3/9 symplastic leiomyomas and in 1/5 leiomyosarcoma. Ki67 labeling in usual leiomyomas was on average 2.4% (range, 1% to 5%) and in symplastic leiomyomas was 1.8% (range, 1% to 5%). Mitoses were absent in all cases of usual and symplastic leiomyomas. Mitotic figures averaged 4.7 (range, 1 to 7) and 13.5 (range, 7 to 20) per 10 HPF for the grade 1 and 2 leiomyosarcomas, respectively. None of the symplastic leiomyomas recurred after a median follow-up of 27 months. The 2 patients with grade 2 leiomyosarcoma had no evidence of metastases at 6 and 7 months follow-up, respectively. Scrotal symplastic leiomyomas may have an ill-defined infiltrative border, which along with their atypia mimic malignancy. Ki67 is low in symplastic leiomyomas, which along with their favorable follow-up and experience in other organs justifies a benign diagnosis. High cellularity and high mitotic activity are the most reliable features for the diagnosis of scrotal leiomyosarcoma.

Mitotic Index is an Independent Predictor of Recurrence-Free Survival in Meningioma

While World Health Organization (WHO) grading of meningioma stratifies patients according to recurrence risk overall, there is substantial within-grade heterogeneity with respect to recurrence-free survival (RFS). Most meningiomas are graded according to mitotic counts per unit area on hematoxylin and eosin sections, a method potentially confounded by tumor cellularity, as well as potential limitations of accurate mitotic figure detection on routine histology. To refine mitotic figure assessment, we evaluated 363 meningiomas with phospho-histone H3 (Ser10) and determined the mitotic index (number of mitoses per 1000 tumor cells). The median mitotic indices among WHO grade I (n = 268), grade II (n = 84) and grade III (n = 11) tumors were 1, 4 and 12. Classification and regression tree analysis to categorize cut-offs identified three subgroups defined by mitotic indices of 0-2, 3-4 and ≥5, which on univariate analysis were associated with RFS (P < 0.01). In multivariate analysis, mitotic index subgrouped in this manner was significantly associated with RFS (P < 0.01) after adjustment for Simpson grade, WHO grade and MIB-1 index. Mitotic index was then examined within individual WHO grade, showing that for grade I and grade II meningiomas, mitotic index can add additional information to RFS risk. The results suggest that the use of a robust mitotic marker in meningioma could refine risk stratification.

Comparative diagnostic and prognostic performances of the hematoxylin-eosin and phospho-histone H3 mitotic count and Ki-67 index in adrenocortical carcinoma

Mitotic count on hematoxylin and eosin slides is a fundamental morphological criterion in the diagnosis and grading of adrenocortical carcinoma in any scoring system employed. Moreover, it is the unique term strongly associated with patient's prognosis. Phospho-histone H3 is a mitosis-specific antibody, which was already proven to facilitate mitotic count in melanoma and other tumors. Therefore, a study was designed to assess the diagnostic and prognostic role of phospho-histone H3 in 52 adrenocortical carcinomas, comparing manual and computerized count to standard manual hematoxylin- and eosin-based method and Ki-67 index. Manual hematoxylin and eosin and phospho-histone H3 mitotic counts were highly correlated (r=0.9077, P<0.0001), better than computer-assisted phospho-histone H3 evaluations, and had an excellent inter-observer reproducibility at Bland-Altman analysis. Three of 15 cases having <5 mitotic figures per 50 high-power fields by standard count on hematoxylin and eosin gained the mitotic figure point of Weiss Score after a manual count on phospho-histone H3 slides. Traditional mitotic count confirmed to be a strong predictor of overall survival (P=0.0043), better than phospho-histone H3-based evaluation (P=0.051), but not as strong as the Ki-67 index (P<0.0001). The latter further segregated adrenocortical carcinomas into three prognostic groups, stratifying cases by low (<20%), intermediate (20-50%), and high (>50%) Ki-67 values. We conclude that (a) phospho-histone H3 staining is a useful diagnostic complementary tool to standard hematoxylin and eosin mitotic count, enabling optimal mitotic figure evaluation (including atypical mitotic figures) even in adrenocortical carcinomas with a low mitotic index and with a very high reproducibility; (b) Ki-67 proved to be the best prognostic indicator of overall survival, being superior to the mitotic index, irrespective of the method (standard on hematoxylin and eosin or phospho-histone H3-based) used to count mitotic figures.

Current breast cancer proliferative markers correlate variably based on decoupled duration of cell cycle phases

Mitotic count, PhH3, and MIB-1 are used as measures of the proportion of proliferating malignant cells in surgical pathology. They highlight different stages of the cell cycle, but little is known about how this affects their counts. This study assesses the strength of their correlations and attempts to determine the relationship between them. Proliferation counts for forty-nine consecutive cases of invasive breast carcinomas were analyzed, with the same tumor area on each stain counted using digital image analysis. The integrated optical density (IOD) of nuclei was measured as an approximation of nuclear DNA content. PhH3 strongly correlated with mitotic count (r = 0.94). Weaker correlations were found between MIB-1 versus PhH3 (r = 0.79) and mitotic count (r = 0.83). Nuclear IOD showed stronger correlation with MIB-1 (r = 0.37) than to mitotic count (r = 0.23) and PhH3 (r = 0.34). With evidence from a literature review, it is suggested that the weaker correlations with MIB-1 are not explained by count imprecision or error, but relies on temporal decorrelation between cell cycle phases. Consequences on correlation between these proliferative markers are illustrated by mathematical models.