Super scans associated with bronchial carcinoma

Full text: Introduction: It is most unusual for bronchial carcinoma to present as a malignant super scan and is not mentioned in the literature as a specific cause for metabolic super scans. Yet the clinical impression developed that metabolic super scans are not uncommon with bronchial carcinoma possibly associated with paraneoplastic hyperparathyroidism. Purpose: (a) to determine the prevalence of super scans in bronchial carcinoma; (b) to determine a possible association with a specific histological type of carcinoma; (c) to determine the serum Ca++, PO4 and alkaline phosphatase levels pretreatment, thus a possible underlying paraneoplastic hyperparathyroidism. Methods: Hundred patients with bronchial carcinoma were drawn randomly from our files over the last 3 years and studied retrospectively for presence of a possible metabolic super scan. A metabolic super scan was defined as markedly increased diffuse bone uptake without irregularities or possible localized metastases. The kidneys must be absent or scarcely visible. These patients were further evaluated with regards to (a) histopathological type of carcinoma (b) pre therapeutic serum Ca++, PO4 and alkaline phosphatase levels. Results: (i) Metabolic super scans were observed in 11 % of our study group; (ii) The serum Ca++ was only slightly increased in one patient. Serum PO4 was normal in all the patients. Thus we could not prove a serum Ca++/PO4 profile suggestive of hyperparathyroidism in our patients. In two patients parathyroid hormone levels were available and were WNL; (iii) The alkaline phosphatase was moderately increased in 4 patients. (The reason uncertain but probably due to increased bone activity and bone turnover since liver metastases were confirmed in only one of these patients). (iv) Seven patients had non small cell carcinoma, three small cell and one unclassified, thus not limited to epidermoid cancer alone. Conclusion: In this study the underlying pathophysiology for the metabolic super scan of bronchial carcinoma appeared not to be associated with hyperparathyroidism but probably due to another cause. (author)