technetium-tc-99m-medronate and Mesothelioma

Case report.. We report malignant pleural mesothelioma (MPM) discovered in a Tc-99m MDP bone scan as a photopenic lesion in a 64-year-old man presenting with low back pain and diagnosed with F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).. Malignant pleural mesothelioma, an uncommon neoplasm with a poor prognosis, arises from mesothelial cells of the pleura. Typically, the patient presents with either chest pain or symptoms derived from a pleural effusion such as dyspnea, or both. Most cases of MPM are initially detected on chest radiographs and primarily diagnosed with a CT scan.. Case study with bone scan and F-18 FDG PET/CT.. The Tc-99m MDP bone scan showed a photopenic defect occupying the left side of the T11 vertebra and implicated the existence of a tumor. Pathologic analysis of the paraspinal tumor indicated metastatic neoplastic cells, which we initially suspected originated from the gastrointestinal tract. The CT and magnetic resonance imaging showed no additional information about the primary malignancy; therefore, we did an F-18 FDG PET/CT study, which suggested malignant pleural mesothelioma.. The present case highlights both the value of a Tc-99m MDP bone scan when MPM presents, unusually, as low back pain, and the importance of carefully interpreting bone scan images, especially for photopenic defects. It also indicates the usefulness of F-18 FDG PET/CT study in MPM in a difficult histopathological diagnosis.

Topics: Fluorodeoxyglucose F18; Humans; Low Back Pain; Male; Mesothelioma; Middle Aged; Pleural Neoplasms; Positron-Emission Tomography; Radiopharmaceuticals; Technetium Tc 99m Medronate; Tomography, X-Ray Computed

Bisphosphonates are widely clinically used inhibitors of bone resorption. Pre-clinical studies indicate that bisphosphonates also inhibit the growth of various cancer cells in vitro, but their in vivo anti-cancer activity varies greatly, depending on the tumor type. We compared the various cellular effects of bisphosphonates in breast cancer and mesothelioma cells, with differences in growth inhibition responses to bisphosphonate-treatment in vivo. We show that the growth inhibitory effects of nitrogen-containing bisphosphonates are significantly affected by excess Ca(2+) in a cell- and bisphosphonate-specific fashion. Furthermore, excess pyrophosphate-resembling bisphosphonates prevent nitrogen-containing-bisphosphonate-induced accumulation of unprenylated Rap1A, p38 phosphorylation and growth inhibition in human MDA-MB-231 breast cancer and mouse AB-12 mesothelioma cells. For some, but not all tested, pyrophosphate-resembling bisphosphonate: nitrogen-containing bisphosphonate combinations these results may be partially explained by the ability of the excess pyrophosphate-resembling bisphosphonates to chelate Ca(2+). In mice, subcutaneous AB-12 and MDA-MB-231 tumors exhibit positive staining for Ca(2+) minerals, as revealed with Von Kossa stainings. We further show that the AB-12 tumors accumulate significantly more of the bone scanning bisphosphonate, Tc99m-medronate, as compared with MDA-MB-231 tumors. In conclusion, our results suggest that Ca(2+) regulates the growth inhibitory effects of bisphosphonates in a target cell and drug-specific fashion. These findings may be of physiological relevance since many tumor types are calcified. They further suggest that bisphosphonates can accumulate in tumors that are growing at the visceral sites and that differences in tumor accumulation of bisphosphonates may regulate their in vivo sensitivity to these drugs.

Topics: Blotting, Western; Breast Neoplasms; Calcium; Cell Line, Tumor; Cell Survival; Connexin 43; Diphosphonates; Female; Flow Cytometry; Fluorescent Dyes; Humans; Isoquinolines; Mesothelioma; Nitrogen; p38 Mitogen-Activated Protein Kinases; Radiopharmaceuticals; rap1 GTP-Binding Proteins; Receptors, Antigen, T-Cell; Technetium Tc 99m Medronate

The literature is replete with cases of Tc-99m bone imaging agent uptake in pleural effusions. Far rarer is the report of photopenia in a pleural effusion. In this case of malignant mesothelioma, we describe a unique case of unilateral hemithoracic photopenia from a pleural effusion with concomitant uptake in the contralateral lung resulting from calcified pleural plaques. Although initially perplexing clinically, this case can be readily explained with an understanding of basic physiological principles.

Topics: Aged, 80 and over; Bone Neoplasms; Diagnosis, Differential; False Positive Reactions; Humans; Male; Mesothelioma; Pleural Effusion, Malignant; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Medronate

Topics: Adult; Humans; Male; Mesothelioma; Peritoneal Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Medronate

Topics: Humans; Mesothelioma; Middle Aged; Peritoneal Neoplasms; Radionuclide Imaging; Technetium Tc 99m Medronate

The authors report a rare case of a symptomatic hematogenous osseous metastasis from a pleural mesothelioma. The lesion was initially detected by bone scintigraphy and was confirmed by MRI and subsequent open biopsy, despite a negative CT scan.

Topics: Acetabulum; Aged; Bone Neoplasms; Female; Humans; Mesothelioma; Pleural Neoplasms; Radionuclide Imaging; Technetium Tc 99m Medronate