Prognostic factors in giant cell tumor of bone a modified histological grading system useful as a guide to prognosis

Abstract

An analysis of 26 patients with giant cell tumor of bone was carried out to determine the clinical and pathological factors affecting the prognosis of the tumor, with a follow-up program of more than 3 years. The physical characteristics of the pathological features were measured objectively using an image analyzer. A significant correlation between the therapeutic procedures and recurrence of the tumor was found, but no pathological variables were significantly correlated. Excision or resection en bloc should be performed for the initial treatment of the tumor. Local recurrence could not be predicted on the basis of histological grading. Stromal cell atypia was significantly correlated with metastasis, but multinucleated giant cells bore no correlation to either recurrence or metastasis. The use of a modified histological grading system based not on variations of the stroma and giant cells but only on the atypia of mononuclear stromal cells, either malignant or classical, is recommended for the clinical assessment of the tumor.

Histopathological, immunohistochemical, and image analytic parameters characterizing the stromal component in primary and recurrent giant cell tumor of bone

“…The number of giant cells was similar in primary and recurrent groups as seen previously. 4 Other features like stromal cell nucleoli score, giant cell nucleoli score, stromal cell groove score, and giant cell groove score were also not significantly different in primary and recurrent GCT.…”

“…There is marked subjectivity in the histopathological grading systems and many reports on the correlation of histological features and prognosis have concluded that it is impossible to judge whether or not a GCT of bone is likely to recur from its histological characteristics. 4,15 At present, no grading system has proved to have prognostic relevance. Recent understanding of the cellular components of GCT and its molecular and cytokine-mediated derivation has shed new light on the nature of GCT.…”

“…Nuclear grading was done (Grade 1 with stromal cells lacking pleomorphism and hyperchromasia, Grade 2 having stromal cells showing nuclear enlargement and pleomorphism without significant hyperchromasia or atypical mitosis, Grade 3 showing marked pleomorphism accompanied by hyperchromasia and presence of occasional atypical mitosis). 4 The number of mitotic figures was counted per 10 high power fields in the areas with highest mitotic activity. Percentage of spindle cells in the stroma was calculated by counting 500 cells under high power with examination of at least 10 fields.…”

“…3 A range of morphological appearances are seen from specimen to specimen and from section to section. 4 The histogenesis and the relationship between multinucleated giant cells and mononuclear stromal cells of GCT have been recently better understood with both neoplastic and non-neoplastic reactive cells considered to be contributing to the stromal component. The neoplastic stromal cells are believed to arise from primitive osteoblastic cells while the reactive component is believed to arise from bone marrow-derived monocytic cells.…”

“…7,8 Previous studies have not found any significant difference in the proliferation of neoplastic cells between primary and recurrent GCT. 4,9,10 The present study was undertaken to evaluate whether delineation of reactive and neoplastic component of GCT using immunohistochemistry can help in deriving histopathological performance indicators which differ in primary and recurrent GCT. Nuclear morphometry of immunostained slides by image analysis was used for more accurate measurement and to assess the utility of this approach.…”