Incidental Cardiac Uptake on 99mTc-HMDP Bone Scintigraphy in Oncology Patients: Two Cases of Transthyretin Amyloid Cardiomyopathy with Literature Review.

BACKGROUND

Bone scintigraphy using technetium-99m hydroxymethylene diphosphonate (99mTc-HMDP) is extensively employed to detect bone metastases. However, incidental myocardial uptake may indicate wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM), a frequently overlooked diagnosis with important clinical implications.

CASE PRESENTATION: Two elderly female patients with a history of breast cancer were subjected to 99mTc-HMDP bone scintigraphy as part of a routine evaluation for possible bone metastases. Both cases demonstrated incidental myocardial uptake (Perugini Grade 2 and Grade 3, respectively), raising suspicion for ATTRwt-CM, which was subsequently confirmed by endomyocardial biopsy.

REVIEW OF THE LITERATURE: We reviewed published studies reporting cardiac uptake on bone scintigraphy, summarizing the frequency, patient demographics, and tracer types, and emphasizing the clinical relevance of this finding in cancer patients.

CONCLUSIONS

In oncology patients, bone scintigraphy performed during routine metastatic screening may facilitate early detection of ATTRwt-CM, enabling timely diagnosis and treatment initiation, potentially improving clinical outcomes.