[Small cell malignant tumors of bone: comparison between diagnosis using core needle biopsies and surgical specimens].

OBJECTIVE

To compare the pathologic diagnosis and immunohistochemistry of small cell malignant tumors (SCMT) of bone using both core needle biopsy and surgical specimen.

METHODS

Seventy-seven cases of SCMT with core needle biopsies and surgical specimens available were respectively analyzed by histologic examination and immunohistochemical study, with literature review.

RESULTS

The male-to-female ratio was 48:29. The age of the patients ranged from 6 to 73 years. The tumors studied included Ewing sarcoma/PNET (n = 38), myeloma (n = 23), lymphoma (n = 10), small cell osteosarcoma (n = 2), small cell carcinoma (n = 2) and mesenchymal chondrosarcoma (n = 2). The tumors involved limbs, axial skeleton and flat bones. Microscopically, the tumors shared similar histology, with small round cells and spindly cells arranged in diffuse sheets. The pathologic diagnosis by core needle biopsies correlated with that by surgical specimens in 84.4% (65/77) of the cases.

CONCLUSIONS

SCMT represents a heterogeneous group of malignancy. Correlations with clinicoradiologic findings and application of ancillary investigations including immunohistochemistry and molecular study are important for definitive diagnosis. Pathologic diagnosis using core needle biopsies shows good results and provides useful information for surgical planning.