small cell osteosarcoma
Small cell osteosarcoma may present a challenging primary diagnosis on cytologic assessment owing to its rarity and its morphologic similarity to other small round blue cell tumors.
Small cell osteosarcoma shares many of the well-described cytomorphologic features of classic osteosarcoma, but the relatively small cells, round hyperchromatic nuclei, and scant osteoid constitute the common denominator. Correlation with radiographic findings and ancillary tests can aid in definitive diagnosis.
Small cell osteosarcoma is a distinct subtype with a histologic appearance in which the bulk of the lesion is composed of round malignant cells with minimal areas of spindle cells. Osteoid production is always present.
The lesion may mimic Ewing’s tumor and other lesions in which round cells are seen. We report the clinical, radiologic, and pathologic features of this tumor, as well as the clinical outcome and response to therapy.
Synopsis
relatively small to intermediate cell size
high nuclear/cytoplasmic ratios
round nuclei
minimal anisonucleosis
finely granular nuclear chromatin
fine cytoplasmic vacuoles
only rare osteoid.
Open access references
Small cell osteosarcoma: cytopathologic characteristics and differential diagnosis. Bishop JA, Shum CH, Sheth S, Wakely PE Jr, Ali SZ. Am J Clin Pathol 2010;133(5):756-61. PMID: #20395522# (Free)
References
Histopathological characterization of small cell osteosarcoma with immunohistochemistry and molecular genetic support. A study of 10 cases. Machado I, Alberghini M, Giner F, Corrigan M, O’Sullivan M, Noguera R, Pellin A, Bertoni F, Llombart-Bosch A. Histopathology 2010;57(1):162-7. PMID: #20557371#
Bertoni F, Present D, Bacchini P, Pignatti G, Picci P, Campanacci M. The Istituto Rizzoli experience with small cell osteosarcoma. Cancer 1989;64(12):2591-9. PMID: #2684389#
Ayala AG, Ro JY, Raymond AK, Jaffe N, Chawla S, Carrasco H, Link M, Jimenez J, Edeiken J, Wallace S, et al. Small cell osteosarcoma. A clinicopathologic study of 27 cases. Cancer 1989;64(10):2162-73