Tumours induced in mice, either CBA normal and chimaerical, or C3H, by 90Sr or 226Ra or plutonium have been examined histochemically with (1) diazotate fast red violet LB salt in naphthol AS-MX phosphate buffer at pH 8·6 and 5·2, (2) 1: 9 dimethyl methylene blue (Taylor).
It is concluded:
(a) The diagnosis of osteosarcoma is facilitated with Taylor's Blue which stains osteoid metachromatically. Cells of osteosarcoma, like normal osteoblasts, contain alkaline phosphatase but this may be lost by mutation either in the original tumour or subsequently on passage of the tumour serially to compatible hosts.
(b) Osteosarcomata may contain giant-cells of two forms, bizarre tumour cells and osteoclasts; the latter contain acid phosphatase. Osteosarcomata which retain their osteoid on serial passage have few cells containing acid phosphatases.
(c) Primitive mesenchymal cell tumours of angiomatous form may occur, if the bone marrow is irradiated, e.g. by 90Sr-90Y and Pu. These tumours lack osteoid and cells interpretable as osteoblasts or osteoclasts (though they destroy bone).
(d) Tumours classifiable as fibrosarcomata occur rarely, and may be truly of fibroblastic origin or be mutated osteosarcomata.
(e) Lymphomata also occur when the marrow is irradiated (90Sr-90Y and Pu). They may be generalized, when their cells may contain alkaline phosphatase or lack it. They may be localized to abdominal viscera, the reticulo-sarcomatous form, in which case the cells lack alkaline phosphatase.