Mitotic Counts (mitotic + count)

Distribution by Scientific Domains


Selected Abstracts


Cytologic feature by squash preparation of pineal parenchyma tumor of intermediate differentiation

DIAGNOSTIC CYTOPATHOLOGY, Issue 10 2008
Keiji Shimada M.D., Ph.D.
Abstract Pineal parenchyma tumor of intermediate differentiation (PPTID) is a very rare intracranial tumor, and pathological investigation limited to immunohistological and ultrastructural analyses have been published to date. Although intraoperative cytology is one of the important approaches for initial diagnosis in brain tumors, no or little studies on cellular morphology of PPTID have been demonstrated due to its rarity. We report here cytological features of PPTID obtained from stereotactic surgical specimens in a case of 27-year-old female manifested by dizziness and diplopia. Brain MRI revealed an unhomogeneously enhanced, large-sized tumor (56 × 52 × 60 mm) mainly located in the pineal region expanding from the midbrain to superior portion of the cerebellum and the fourth ventricle. Squash cytology showed increased nucleocytoplasmic ratio, hyperchromatic nuclei, and small rosette-like cell cluster but cellular pleomorphism was mild to moderate and necrotic background was not observed. Histology showed high cellularity, moderate nuclear atypia, and small rosette formation but neither bizarre tumor cells nor necrosis was present. Mitotic counts were very low (less than 1 per 10 high-power fields) and the MIB-1 labeling index was relatively high (10.1%). Tumor cells were immunohistochemically positive for neural markers such as synaptophysin, neurospecific enolase but not for glial fibrillary acidic protein or S-100. In some parts, cells were strongly reactive for neurofilament protein. Taken together, we made a final diagnosis of PPTID. This is the first presentation of cytological analysis by squash preparation that gives an important clue to accurate diagnosis of pineal parenchymal tumor and to understand its malignant potential. Diagn. Cytopathol. 2008;36:749,753. © 2008 Wiley-Liss, Inc. [source]


Trends in incidence and survival of mesenchymal neoplasm of the digestive tract within a defined population of Northern Norway,

APMIS, Issue 3 2006
SONJA ERIKSSON STEIGEN
Population-based incidence and survival data for gastrointestinal stromal tumor (GIST) are sparse due to the fact that GIST is a rather novel entity both clinically and pathologically, and has not been registered as a separate entity in population-based cancer registries. The aim of the present study was to reclassify all mesenchymal tumors within a defined population of northern Norway over a time-span of 30 years with the purpose of estimating trends of incidence and survival. One hundred and forty-one patients with mesenchymal neoplasms of the digestive tract were identified: 102 as GISTs, 32 as leiomyomatous tumors, 4 as schwannomas, and 3 as fibromas. Incidence rates of GIST showed a significant increase over the whole period, which was not observed for the non-GIST cases. Analysis of GIST cases showed that cases with more than 5 mitoses per 50 high power fields had an increased expected mortality 4 times that of those with fewer mitoses, and the combination of mitotic count and size of tumor can be recommended for categorizing the tumors into different risk levels. The study confirms that GIST is by far the most frequent mesenchymal neoplasm of the digestive tract and that the incidence has increased over the last 30 years. [source]


Unusual recurrent orbital tumour

ACTA OPHTHALMOLOGICA, Issue 2007
LD IRION
Purpose: We present a case of an unusual CD34+ recurrent orbital tumour. Methods: A 62-year-old male presented with progressive left proptosis and preserved visual acuity. CT scans showed a circumscribed mass at the inferomedial orbit. After incisional biopsy, the patient preferred conservative treatment and the lesion was debulked. Further debulking was necessary in other two occasions. With radiological signs of bone invasion, left orbital exenteration was agreed in the fourth relapse. Results: The lid skin sparing exenteration revealed a tumour mass (45 x 29 x 27 mm) in the inferomedial orbit. There was no evidence of invasion of either the globe or the optic nerve. In all occasions, the tumour consisted of spindle cells alternating vague storiform areas with patternless areas. The tumour was very cellular, showed low mitotic count and no necrosis or ulceration. There was focal invasion of fibrous tissue, extra-ocular muscle, fat and bony fragments. The tumour was diffusely and consistently positive for CD34, S100 and vimentin. EMA and CD99 were focally positive. Several other markers were negative. This slow growing lesion with low grade histological appearance and EM suggestive of Schwannian processes was diagnosed as a CD34 positive Schwannoma on the first debulking. In the next two recurrences, experts agreed with a diagnosis of a DFSP based on the diffuse positivity for CD34. In the exenteration specimen, due to the exceptional location of the presumable DFSP, this diagnosis was disputed and after EM and further reviews the case was concluded as variant of low grade MPNST. Conclusions: The consistent positivity for CD34 in our case has lead to diagnostic disagreement. Only after the fourth recurrence the final diagnosis of a CD34 positive low grade PNST could be made. [source]


Histological grading of invasive breast carcinoma , a simplification of existing methods in a large conservation series with long-term follow-up

HISTOPATHOLOGY, Issue 6 2009
Jeremy St J Thomas
Aims:, To assess the validity of grading in the Edinburgh Breast Conservation Series; a consecutive cohort of 1812 early breast cancer patients treated by breast conservation and radiotherapy between 1981 and 1998 in a single specialist centre with ,9 years' follow-up and full staging data. Methods and results:, A single pathologist (J.St.J.T) graded 1650 cases using the Elston and Ellis method (EE) with particular reference to the component data: acinar differentiation, nuclear pleomorphism and mitotic counts. The original method was then compared with binary scoring of the same components and the relationship to prognosis reassessed. EE grades and individual grade components were prognostic (P < 0.0001) with 10-year cause-specific survival of 95.6%, 86.4% and 74.7% for EE grades 1, 2 and 3, respectively. A binary scoring of grade components produces four groups, splitting EE grade 2 tumours into two groups with different outcomes , 10-year survival rates for the four revised grades were 96.0%, 89.0%, 79.7% and 75.4%, respectively. Conclusions:, Existing grading methodology is fully applicable in the narrower context of a conservation series but can be simplified. Subdivision of EE grade 2 into a true intermediate prognosis group and a second group with a worse prognosis also adds benefit. [source]


Increased KIT signalling with up-regulation of cyclin D correlates to accelerated proliferation and shorter disease-free survival in gastrointestinal stromal tumours (GISTs) with KIT exon 11 deletions,

THE JOURNAL OF PATHOLOGY, Issue 2 2008
F Haller
Abstract Gastrointestinal stromal tumours (GISTs) with deletions in KIT exon 11 are characterized by higher proliferation rates and shorter disease-free survival times, compared to GISTs with KIT exon 11 point mutations. Up-regulation of cyclin D is a crucial event for entry into the G1 phase of the cell cycle, and links mitogenic signalling to cell proliferation. Signalling from activated KIT to cyclin D is directed through the RAS/RAF/ERK, PI3K/AKT/mTOR/EIF4E, and JAK/STATs cascades. ERK and STATs initiate mRNA transcription of cyclin D, whereas EIF4E activation leads to increased translation efficiency and reduced degradation of cyclin D protein. The aim of the current study was to analyse the mRNA and protein expression as well as protein phosphorylation of central hubs of these signalling cascades in primary GISTs, to evaluate whether tumours with KIT exon 11 deletions and point mutations differently utilize these pathways. GISTs with KIT exon 11 deletions had significantly higher mitotic counts, higher proliferation rates, and shorter disease-free survival times. In line with this, they had significantly higher expression of cyclin D on the mRNA and protein level. Furthermore, there was a significantly higher amount of phosphorylated ERK1/2, and a higher protein amount of STAT3, mTOR, and EIF4E. PI3K and phosphorylated AKT were also up-regulated, but this was not significant. Ultimately, GISTs with KIT exon 11 deletions had significantly higher phosphorylation of the central negative cell-cycle regulator RB. Phosphorylation of RB is accomplished by activated cyclin D/CDK4/6 complex, and marks a central event in the release of the cell cycle. Altogether, these observations suggest increased KIT signalling with up-regulation of cyclin D as the basis for the unfavourable clinical course in GISTs with KIT exon 11 deletions. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]


Frequency of the basal-like phenotype in African breast cancer,

APMIS, Issue 12 2007
HAWA NALWOGA
Basal-like breast carcinoma has been recognized as a subtype with specific prognostic implications. However, there is a lack of reports about this category of breast tumors in African women. The aim of this study was to explore the basal-like phenotype in breast cancer patients in an African population, and a registry-based series was included from the well-defined Kyadondo County in Uganda (1.7 millions). We studied a total of 65 archival paraffin blocks of invasive breast cancer using antibodies against cytokeratin 5/6 and P-cadherin, and these markers were expressed in 34% of all cases and in 52% of ER (estrogen receptor)-negative tumors. All basal-like tumors were ER negative (p<0.0005) and PR (progesterone receptor) negative (p=0.002). Basal-like breast carcinomas were of a higher histologic grade (p=0.001), had high mitotic counts (p=0.002), and marked nuclear pleomorphism (p=0.002). P-cadherin-positive tumors had a high Ki-67 proliferative rate (p=0.039). In conclusion, the basal-like phenotype is frequent in this African series of breast cancer and is strongly associated with poor prognostic factors. Our findings might be significant in relation to clinical management of these patients, including novel targeted therapy. [source]