SAN FRANCISCO -- Mitotic rate
was not found to be a good indicator for the outcome of sentinel lymph node (SLN) biopsy in thin tumors, in an analysis of melanoma cases.
The mitotic rate
is generally low and necrosis is uncommon.
Risk of aggressive behavior in gastrointestinal stromal tumor Size (largest dimension) Mitotic count Very low risk <2 cm <5/50 HPF Low risk 2-5 cm <5/50 HPF Intermediate risk <5 cm 6-10/50 HPF 5-10 cm <5/50 HPF High risk >5 cm >5/50 HPF >10 cm any mitotic rate
HPF: high power fields
Histopathological examination of mass revealed large number of large plump spindle shaped atypical endothelial neoplastic cells with pleomorphism and high mitotic rate
The microscopy revealed multiple foci of neoplastic osteoid surrounded by atypical spindle cells having hyperchromatic nuclei with high NC ratio and a mitotic rate
of about 7/10 HPF.
The grading system for STSs in dogs is based on scores for 3 categories: degree of differentiation, mitotic rate
, and the presence of necrosis.
Patients were divided into four prognostic groups (very low, low, intermediate and high risk) by tumour size, location and mitotic rate
as variables in order to evaluate the likelihood of GIST malignant behaviour (Table 1).
Based on the pathological findings of large tumor size, nuclear atypia, increased mitotic rate
, atypical mitosis, the presence of necrosis, and characteristic immunohistochemistry, the diagnosis of malignant glomus tumor was rendered.
The mitotic rate
was 54 per 10 high-power fields (HPFs) and both tumors were assigned grade 3.
Although low mitotic rate
does not guarantee the benign behavior, these findings support mitotic activity being the most reliable histologic criterion for dividing benign from malignant stromal tumors .
Results: Our study did not show a difference in mitotic rate
between treatment arms in those subjects that were sacrificed at 14 days.
This reactive process was considered in a differential diagnosis due to lack of frank tumour cell necrosis, marked cellular pleomorphism, relatively low mitotic rate
(3 mitoses/10 high power fields), and atypical mitoses.