No abstract

The patient was a 64-year-old married woman who had borne two children. Both children had been bottle-fed. She was seen in the breast clinic on 20 August 1976 with a history of a lump in the left breast of nine months' duration. The lump had been painful on occasions and she was aware of an inincrease in size. She had lost 1 5 stones (9 53 kg) in weight. There was no history of previous breast disease or discharge from the nipple. The menopause had been at the age of 50 years.On examination there was a clinical carcinoma, 4 0 cm in diameter, in the lower outer quadrant of the left breast. The skin was tethered but there was no ulceration. Nodes were felt in the left axilla.The right breast and axilla were normal. Mammography showed an opacity, measuring approximately 3-0 cm, in the lower outer quadrant of the left breast. The opacity was noted to have irregular margins and the radiological features of malig-

Three examples of primary signet ring cell carcinoma of the breast are described. This form of breast carcinoma deserves recognition as an entity because its prognosis may differ from colloid carcinoma of the breast and because of potential difficulty in distinguishing it from metastatic carcinoma.

The ultrastructural characteristics of mucin production in mammary mucoid carcinoma, signet ring cell carcinoma (Harris, Wells & Vasudev 1978), papillary carcinoma and lobular carcinoma are compared. The mucin in lobular carcinoma is confined to intracytoplasmic lumina whereas it is present as membrane bound granules in the other three types, although intracytoplasmic lumina also occur in the latter. A possible origin of intracytoplasmic lumina from distended Golgi cisternae is proposed. Possibly, extracellular mucin acts as a mechanical barrier between tumour cells and lymphatics, thus explaining the good prognosis of typical mucoid carcinomas.

A lipid rich rhabdomyosarcoma of the paratesticular region was studied by light microscopy, histochemistry, immunohistochemistry and electron microscopy. The tumour was composed of primitive looking, vacuolated, and pleomorphic cells. Lipid was present in varying amounts in all cells but was especially abundant in the vacuolated and pleomorphic cells. Some cells showed eosinophilic fibrillary cytoplasm but cross-striations were not seen. Tumour cells were positive for desmin, muscle specific actin, and vimentin. A few cells were myoglobin positive. At electron microscopy, the presence of lipid was confirmed, while thick and thin filaments, Z disks, lamina and glycogen were observed, thereby confirming striated muscle differentiation.Although moderate amounts of lipid can be expected in almost any tumour, lipid rich rhabdomyosarcomas have received little attention. The present report provides a comprehensively examined case of such a tumour initially presenting diagnostic difficulty because of its possible confusion with liposarcoma. (7 Clin Pathol 1994;47:280-282) Rhabdomyosarcomas are usually divided into three main types: embryonal, pleomorphic, and alveolar. Mixed,' solid,2 spindle cell,3 clear cell4 and lipid rich5 types have been described. We describe a case of lipid rich mixed rhabdomyosarcoma occurring in the paratesticular region, which initially presented diagnostic confusion with liposarcoma.