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We report a patient with a metastatic parathyroid carcinoma and medullary carcinoma of the thyroid. This patient represents a variation of the multiple endocrine neoplasia syndrome (MEN) type 2A. There was no evidence of a phaeochromocytoma. The case illustrates the difficulties that may be encountered in localising the source of PTH secretion; the patient underwent four unsuccessful exploratory operations of the neck and mediastinum before further investigations revealed a single metastatic deposit of parathyroid carcinoma involving the first thoracic vertebra. PCR amplification and sequencing of the RET oncogene from the metastatic parathyroid carcinoma and genomic DNA revealed a heterozygous mutation (Cys634Tyr) in exon 11, as has previously been described to occur in MEN 2A. In addition, loss of tumour heterozygosity was demonstrated at loci from chromosomes 1, 2, 3p, 13q and 16p. This represents the first report of a parathyroid carcinoma in a MEN2A patient, in which the multiple allelic deletions are consistent with the generalised losses observed in aggressive tumours.

Diabetic muscle infarction is a rare condition which may present to a rheumatologist. It was first reported in 1965. Two illustrative cases are described here and the mechanisms of pathogenesis discussed. Analysis of the published data, results of the muscle biopsies, and a technetium-99m sestamibi scan suggest that the condition, which occurs against a background of diabetic microangiopathy, can be triggered by an ischaemic event and causes extensive muscle necrosis through hypoxia-reperfusion injury and compartment syndrome.

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Summary Tc-99m 2 methoxy-isobutyl-isonitrile (9SmTc-MIBI), also called Sestamibi, is a safe and effective scanning agent in solid tumours. Its use in imaging lesions in multiple myeloma has been studied in 21 patients with either multiple myeloma (19/21) or monoclonal gammopathy of undetermined significance (MGUS) (2/ 21). 99mTc-MIBI scanning was positive in 14 patients, 13 with active myeloma and one patient with MGUS showing possible transformation to a more accelerated phase. In seven patients 99mTc-MIBI scanning was negative. In four of them, the result was unexpected, as they had the features of active myeloma. All four were either primarily or secondarily resistant to chemotherapy, with high total cumulative doses of doxorubicin. Overexpression of P-glycoprotein associated with multidrug resistance could be a factor, as it has been shown that 99'Tc-MIBI is actively eliminated from the cell by P-glycoprotein. With this assumption, sensitivity of the scanning technique in this series is 100%, and the specificity 88%. No A dose of 450 MBq of 99mTc-MIBI was administered to each patient. After reviewing 10 min, 1, 4 and 24 h planar images, those done at 1 and 4 h after injection were obtained and evaluated in each patient. A Siemens Orbiter 75 gamma camera equipped with a low-energy, general purpose parallelhole collimator linked to a Micas V computer (Park Medical) was used. Pulse height analysis was carried out with a 15% window on the peak energy of 140 keV for 99mTc-MIBI. A posterior view of the pelvis was done for 600 000counts; the other spot views, anteriorly and posteriorly of the body, were acquired with the same preset time. Physiological uptake of 99mTc-MIBI was seen in the heart, thyroid and salivary glands, spleen, kidneys, bladder, lungs, skeletal muscle, liver, gall bladder, biliary system and both small and large intestines.Criteria of assessment All examinations were carried out by two nuclear medicine physicians who were unaware of the radiological findings. Results were considered concordant if the detected area of abnormal uptake of 99mTc-MIBI matched the osteolytic lesion detected on skeletal survey.In 2/21 patients magnetic resonance imaging (MRI) scanning was considered necessary to determine the anatomy of the lesion.The patients were clinically and biochemically examined when the 99mTc-MIBI and skeletal survey were performed, in order to determine their clinical status (active disease, remission or plateau phase).Haematological and biochemical examination included a full blood count, liver and renal function tests, serum immunoglobulin levels, protein electrophoresis, C-reactive protein, and urine light chain excretion.Information relating to the date of onset of the disease, previous treatment (particularly the cumulative total dose of anthracycline given), response to treatment, possible recurrences and their management was noted, so that active disease which was apparently resistant to chemotherapy could be identified.