Humerus with thyrocarcinomatous metastasis
GC.7121
Medial half of a sagittal section of a left arm and elbow showing a thyreocarcinomatous metastasis in the humerus
From a female aged 65 years in whom the primary carcinoma was obvious in the thyreoid gland. Spontaneous fracture of the humerus occurred and the limb was amputated on account of its uselessness, its increasing weight and to ease the general discomfort.
The distal half of the humerus is decalcified and the bone destroyed but the cartilage of encrustation has not been perforated and the elbow joint is not involved. A part of the radius is shown in section. The tumour forms an oval mass to which the compressed tissues form a fairly definite capsule. Necrosis and liquefaction have formed an irregular cavity in the centre of the tumour and this is surrounded by amorphous necrotic material towards the periphery of which are numerous vascular spaces and some pigmentation from haemorrhage. The periphery of the tumour forms a layer which varies up to 15 mm. in depth in which the tissue appears to be arranged vertically to the surface. Some subperiosteal effusion and hyaline-looking tissue indicate extension of the disease along the humerus. Microscopically
the tumour has the structure of an atypical secondary carcinoma of thyreoid origin. It contains no colloid.
