Focal uptake of Tc-99m MDP in a gossypiboma

A 51-year-old Korean woman with a history of breast cancer underwent screening bone scintigraphy, which revealed minimal soft tissue uptake of Tc-99m methylene diphosphonate (MDP) in the right lower quadrant. CT and plain films confirmed that the uptake was due to a retained surgical sponge or gossypiboma. The incidence of gossypibomas has been reported at high as 1 in 1000 to 15,000 intra-abdominal operations. The natural progression of an aseptic gossypiboma is a foreign body reaction and granuloma formation. This inflammatory granulomatous reaction is the most likely cause of the extraosseous accumulation of Tc-99m MDP. This entity should be added to the already extensive list of etiologies of extraosseous MDP accumulation.     

Neuroblastoma: imaging evaluation by sequential Tc-99m MDP, I-131 MIBG, and Ga-67 citrate studies

Fourteen children with histopathologically confirmed neuroblastoma underwent sequential correlative imaging studies using I-131 MIBG, Tc-99m MDP, and Ga-67 citrate during various stages of the disease. Of the patients 86% showed I-131 MIBG accumulation in the primary tumoral site, whereas 71% showed Tc-99m MDP and 79% Ga-67 citrate uptake. In 86% at least one of the two latter radiopharmaceuticals concentrated in the primary tumor. The use of all three radiopharmaceuticals raised the detection rate to 93%. Of the osseous or extraosseous metastases 100% were detected by Tc-99m MDP studies. The I-131 MIBG studies were positive in 71% of the osseous metastases and in 70% of the extraosseous metastases. No Ga-67 citrate uptake was demonstrated in osseous metastases, although one extraosseous lung metastasis concentrated this radiopharmaceutical. Tc-99m MDP bone imaging was the best method for diagnosing metastatic spread of the disease and for monitoring the results of treatment. Primary tumor uptake was best indicated by I-131 MIBG. Both Ga-67 citrate and I-131 MIBG were superior to Tc-99m MDP with regard to accurately demonstrating the extent of primary tumors. Only Tc-99m MDP indicated the relationship of these tumors to the kidneys and neighboring osseous structures, providing early screening of kidney compression. Ga-67 citrate study was mainly indicated in tumors with catecholamine depletion, which failed to concentrate the other two radiopharmaceuticals. I-131 MIBG proved especially useful in detecting neuroblastoma with negative Tc-99m MDP and Ga-67 citrate studies and also proved to be helpful with those cases in which I-131 MIBG was planned for therapy. The following strategy is suggested for evaluating neuroblastoma.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tc-99m diphosphonate uptake in malignant fibrous histiocytoma: a possible iron-related effect

A man with malignant fibrous histiocytoma of the thigh had avid uptake of Tc-99m MDP in the lesion. Review of tissue sections showed considerable accumulation of iron in the tumor. Iron is known to be a potential nidus for deposition of the Tc-99m diphosphonates. A review was made of tissue sections from two other reported cases of malignant fibrous histiocytoma which also had significant accumulation of Tc-99m diphosphonates. Both revealed iron within the tumor. The origin of the iron is unknown (perhaps from necrosis and hemorrhage, from trauma, or from innate phagocytic activity of the histiocytes). However, this observation may serve as a stimulus to studies attempting to discern the underlying mechanisms of extraosseous deposition of the Tc-99m diphosphonates.     

Extraosseous uptake of Tc-99m MDP along the radiation therapy port for recurrent squamous cell carcinoma of the lung

A 73-year-old woman with a history of squamous cell carcinoma of the lung was referred for a follow-up metastatic bone survey. Focal extraosseous accumulation of Tc-99m MDP was identified in the right, paraspinal region, along the radiation therapy port.     

Abnormal scintigraphic evolution in AA hepatic amyloidosis

A patient with AA amyloidosis secondary to ankylosing spondylitis showed intense liver uptake of Tc-99m MDP on bone imaging. The biopsy showed hepatic amyloid deposition. A repeat bone scan with Tc-99m MDP 1 year later was negative, although the clinical signs and liver function tests of the patient had not changed. A mechanism might exist, other than the affinity of amyloid to calcium, which would explain the extraosseous uptake of pyrophosphates and diphosphonates in organs and soft tissues affected by systemic amyloidosis.     

Accumulation of Tc-99m methylene diphosphonate in calcified metastatic lesions of the liver from colonic carcinoma. Comparison with calcification on X-ray computed tomogram

Abnormal accumulation of Tc-99m MDP in two metastatic lesions of the liver was observed in a patient with resected colon carcinoma. Single-photon emission computed tomography (SPECT) revealed characteristic marginal accumulation of Tc-99m MDP in both of those metastatic lesions. X-ray CT showed the corresponding marginal calcification in one of the metastases, but no apparent calcification was observed in the other lesion. Two months later, however, the latter also became calcified on x-ray CT. These findings suggest that the accumulation of Tc-99m MDP in the present case is strongly related to the calcium deposition and that Tc-99m MDP may accumulate in a calcified metastatic lesion before the calcification appears on x-ray CT.     

Different findings in Tc-99m MDP bone scintigraphy of patients with sickle cell disease: report of three cases

Objective Sickle cell anemia is an inherited disorder caused by abnormal hemoglobin, the S hemoglobin. Although vaso-occlusive crises can occur virtually in any organ, they are particularly common in the bony skeleton of affected patients. Bone marrow necrosis, bone infarcts, osteomyelitis, and aseptic necrosis are common complications in patients with sickle cell disease. Beside these abnormalities of the skeletal system, diffuse micro or macro calcification resulting from both splenic infarction and repeated vaso-occlusive episodes in the kidneys can be shown by technetium-99m methylenediphosphonate (Tc-99m MDP) bone scintigraphy. We present here the different osseous and extraosseous abnormalities noted on bone scintigraphies of three patients with sickle cell anemia. Methods Whole-body bone scan was performed after injecting 740 MBq of Tc-99m MDP in three patients with sickle cell disease. Results Tc-99m MDP whole-body image of the first patient showed non-uniform uptake in the anterior and posterior aspects of multiple ribs and bilateral femurs and tibias that was attributed to repetitive infarcts. Additionally, increased activity in shoulders, right elbow, and right knee was consistent with arthritis. Tc-99m MDP image of the second patient demonstrated avascular necrosis of the left femoral head and diffuse activity in the enlarged kidneys. Increased activity in the spleen that was attributed to repetitive infarcts was visualized in bone scan of the third patient. Conclusions In light of the findings in these cases, bone scintigraphy is a reliable imaging method in detecting both osseous and extraosseous abnormalities of sickle cell disease and may be used initially.     

Utility of 24 hour bone scan in evaluation of bone involvement by soft tissue sarcoma

Accumulation of Tc-99m MDP in soft tissue malignancies occurs frequently. When tumor overlaps adjacent bone structures, the bone margins can be indiscernible on a regular bone scan. Additional views should be taken to differentiate bone from tumor, however, separation is sometimes difficult and not always successful. This report presents a patient in whom accumulation of Tc-99m MDP in a liposarcoma of the thigh disappeared on a 24 hour scan and bone margins were seen clearly. A possible mechanism for this phenomenon and its utility are discussed.     

Concentration of Tc-99m MDP in ovarian carcinoma and its soft tissue metastases

A patient with ovarian carcinoma was evaluated for skeletal metastasis with a routine whole body bone scan. Although no bone metastases were visualized, there was dramatic accumulation of tracer in the soft tissues of the abdomen. CT revealed calcifying soft tissue metastases on the liver surface, the bowel serosa, and in the pelvis corresponding to the abnormal areas of Tc-99m MDP uptake. Tumor necrosis and ongoing calcification within the metastatic sites are possible explanations for this unusual soft tissue concentration of the bone-seeking radiopharmaceutical. In patients with metastatic ovarian carcinoma, careful review of extraosseous regions on bone scan images may provide valuable diagnostic information.     

Diagnosis of aneurysmal bone cyst of the mandible. A report of two cases with emphasis on scintigraphic approaches

Aneurysmal bone cyst is rarely found in the mandible, and roentgenographic diagnosis of this condition is not easily made. In this report, the diagnostic value of bone scintigraphy and radionuclide angiography and CT imaging in two cases of aneurysmal bone cyst of the mandible are discussed. Bone scintigraphy with Tc-99m MDP demonstrated ring-like or doughnut-pattern accumulation of radioactivity, which corresponded to the expansile character of the bony lesion. The accumulation of radioactivity was intensive in the peripheral region despite the fact that the lesion was benign. Furthermore, the central rarefaction showed that the lesion was cystic. Radionuclide angiography with Tc-99m HSA, including blood pool scan, did not detect radioactive concentration. Thus bone scintigraphy and radionuclide angiography were found to be essential in the differential diagnosis of aneurysmal bone cyst from other forms of tumor, especially hypervascularized tumor and central hemangioma of the mandible.     

Pentavalent technetium-99m DMSA uptake in pseudofractures of osteomalacia

Tc-99m MDP and Tc-99m (V) DMSA images are described from a 49-year-old woman with chronic renal insufficiency complicated by osteomalacia. Clinical, biochemical, and radiologic bone profiles were compatible with osteomalacia. Osteomalacia is a condition associated with disorders in which mineralization of the organic matrix is defective. All bone lesions visualized with Tc-99m MDP also showed increased uptake of Tc-99m (V) DMSA. Tc-99m (V) DMSA accumulation has been reported in many malignant and some benign conditions. Pseudofractures in osteomalacia could be included in the spectrum of benign lesions that accumulate Tc-99m (V) DMSA.     

Tl-201 uptake in brown tumors of hyperparathyroidism.

Tl-201 chloride bone scans were performed on nine patients with primary hyperparathyroidism just after Tl-201 and Tc-99m parathyroid subtraction scintigraphy. Bone lesions accumulate Tl-201, especially in sites of brown tumor formation. This was proven by the histopathologic examination of two patients. Eight patients had bone scans with Tc-99m MDP. The lesion-to-background ratio was quantified in seven patients for Tl-201 and in four patients for Tc-99m MDP. Tl-201 uptake of the lesions were quantified in two patients. The lesion-to-background ratio was 1.63 +/- 0.21 and 2.51 +/- 0.88 for Tl-201 and Tc-99m MDP, respectively. A Ga-67 citrate scan was performed on one patient, and the lesion-to-background ratio was 1.49 +/- 0.06. The accumulation of Tl-201 in brown tumors of bone might be due to increased blood flow and local metabolic activity. Tl-201 chloride was inferior to Tc-99m MDP in lesion detection. It is concluded that bone imaging with Tl-201 can easily be performed following parathyroid subtraction scintigraphy to delineate the sites of brown tumor formation.     

Massive splenic metastases with localization of a skeletal imaging agent

A 70 year old man with squamous cell carcinoma of the lung underwent Tc-99m sulfur colloid liver-spleen scintigraphy and abdominal CT studies; both studies showed multiple large lesions in the massively enlarged spleen, with a cystic appearance being noted on the CT examination. Two consecutive Tc-99m HMDP bone scintigrams demonstrated mild, diffuse radioactivity in the region of the spleen, indicating extraosseous localization of the bone imaging agent in the spleen and suggesting solid tumor masses rather than cysts. At autopsy, the huge spleen weighing 2,200 gm contained multiple, large, metastatic masses. Some of the masses were undergoing necrosis/liquification which would explain the cystic appearance on CT. While bone scintigraphy plays an important role in the detection of skeletal metastatic lesions, extraosseous localization of the imaging agent can provide additional diagnostic information.     

False-negative scintigraphy with Tc-99m sestamibi in stage IV neuroblastoma.

Tc-99m sestamibi, originally developed for myocardial studies, has been used as a tumor-seeking agent. Recently, the agent also was reported to be a functional tracer to predict multidrug resistance-related p-glycoprotein expression in tumor tissue. The current report presents the authors' experience with sestamibi tumor scintigraphy in a neuroblastoma. Although I-131 MIBG tumor imaging and Tc-99m MDP bone scanning accurately demonstrated the extent of the disease, Tc-99m sestamibi showed no accumulation in primary and metastatic foci. Lack of sestamibi uptake was initially thought to be suggestive of failure to respond to chemotherapy because of p-glycoprotein expression. However, the patient responded well to chemotherapy and complete remission was achieved. The failure of Tc-99m sestamibi to detect a neuroblastoma and the lack of sestamibi accumulation in the tumor may not always be related to chemotherapy resistance.     

Osteogenic sarcoma with pulmonary metastasis visualized by bone imaging

Extraosseous soft tissue metastases from osteosarcoma occasionally accumulate Tc-99m MDP. The authors present a case of osteogenic sarcoma of the femur with a pulmonary metastasis detected by bone imaging with radiographic correlation including CT and magnetic resonance imaging. The implication of the detection of osseous and extraosseous metastasis in these patients by bone imaging is discussed. The changing role of bone imaging in the initial workup and follow-up of patients with osteogenic sarcoma is reviewed in light of the change in course and prognosis of the disease as a result of recent advances in adjuvant chemotherapy.     

Skull base involvement by a nasopharyngeal carcinoma shown by Tc-99m MDP SPECT but not by computed tomography

PURPOSE: Plain radiographs, computed tomography (CT), and more recently magnetic resonance imaging (MRI) are used routinely to stage carcinoma of the nasopharynx. Tc-99m methylene diphosphonate (MDP) SPECT is seldom used for local staging of the disease. MATERIALS AND METHODS: Plain radiographs and CT were used to stage squamous carcinoma of the nasopharynx in a 50-year-old man with a left XII nerve palsy. RESULTS: Findings of the plain radiographs were normal, whereas the CT scan revealed a nonhomogenous hyperdense mass in the nasopharynx but intact underlying bone. Given the symptoms, a Tc-99m MDP planar scan was ordered and showed no enhanced uptake, but SPECT images obtained at the same time revealed markedly increased focal radiotracer uptake in the region of the tumor, indicating osseous involvement. CONCLUSION: Possible bony invasion with a nasopharyngeal carcinoma may be better shown with MDP SPECT than with planar isotope bone scans, plain radiographs, or CT.     

Increased activity on immediate phase of bone imaging does not always indicate increased blood volume

The immediate Tc-99m MDP image of a neoplastic right wrist mass in a 10-year-old boy demonstrated intense focal accumulation that suggested a very vascular tumor, but delayed images showed only slightly increased activity in the mass. A Tc-99m labeled RBC study was performed to permit whole-body blood pool imaging for other vascular lesions, and it did not demonstrate an increased blood volume in the mass. Biopsy showed the tumor to be a Ewing's sarcoma, probably of soft tissue origin. The sarcoma was not very vascular. The intense immediate accumulation of Tc-99m MDP in this case may be attributed to increased microvascular permeability.     

Multifocal primary lymphoma of bone: scintigraphy and MR findings before and after treatment

A case of multifocal primary lymphoma of bone is reviewed. Ga-67 citrate, Tc-99m HMDP, and Tl-201 scintigraphs all showed multifocal radiotracer accumulation. CT showed subtle osteolytic and osteosclerotic changes with surrounding soft tissue density mass. MRI clearly showed abnormal signal intensity in the bone marrow. After systemic chemotherapy and infield radiotherapy, the patient showed clinically complete remission. MRI showed reduction of the extraosseous components, but there was little signal change in the bone marrow despite the clinical response to the therapy. Scintigrams were more useful than MRI and CT for both staging and assessing the early response to therapy. The soluble interleukin-2 receptor level was found to be related to tumor cell activity.     

Tc-99m methylene diphosphonate versus Tc-99m pyrophosphate: biologic and clinical comparison.

The biologic and imaging characteristics of Tc-99m MDP and Tc-99m PPi were compared in animals and patients using freeze-dried bone-imaging kits. Biodistribution data in rabbits showed Tc-99m MDP had slightly higher bone uptake, significantly lower blood levels, and faster urinary excretion compared with Tc-99m PPi. Duplicate studies performed on ten patients showed the following: (a) blood clearance of Tc-99m MDP was more prompt and complete, resulting in significantly lower blood levels at 4 hr; (b) urinary excretion was greater with Tc-99m MDP than with Tc-99m PPi; and (c) Tc-99m PPi showed significant red-cell labeling, whereas Tc-99m MDP did not. Image quality was generally better with Tc-99m MDP than with Tc-99 m PPi, although there was no obvious difference in diagnostic sensitivity between the two agents.     

Technetium-99m diphosphonate imaging of psammocarcinoma of probable ovarian origin: case report and literature review

Technetium-99m methylene diphosphonate (Tc-99m MDP) bone scans have long been used by clinicians to diagnose osseous metastases in patients with cancer. However, in several benign and malignant diseases, notably those characterized by extensive soft tissue calcification, Tc-99m MDP may be taken up by the tumor itself. We present a case of a stage IIIC psammoma-rich low-grade serous carcinoma of the ovary, whose identity and extent of disease were first suggested by Tc-99m MDP scintigraphy. The literature concerning this form of cancer, and the use of Tc-99m MDP bone scans to image soft tissue lesions, are reviewed.