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MRI characterization of a giant benign adipose tissue neoplasm of the foot
Khomotso Paulina Motiang 1
1Radiography, Sefako Makgatho Health Science University, Hartbeespoort, South Africa

Synopsis

Motivation: MRI is the best imaging modality due to its excellent resolution and contrast differentiation of soft tissue. However, MRI is scarce and lengthy, yielding low patient throughput and delays in the diagnosis and management of health conditions. It is crucial to have an appropriate imaging protocol to minimize delays in the management of any health conditions for improved health outcomes and quality of life.

Goal(s): To advocate for early diagnosis and management of health conditions for improved quality of life in developing countries.

Approach: Case study

Results: MRI showed a thin encapsulated lesions with a lobular pattern, which were in line with lipoma.

Impact: Appropriate MRI protocols will minimize unnecessary sequences and improve patient throughput and early diagnosis for improved health outcomes in developing countries.

Background: Lipoma is a common benign soft tissue tumour of adipose tissue origin, accounting for about 50% of soft tissue neoplasms. It is characterized by the proliferation of mature adipose cells that present as a painless, slow-growing mass in the subcutaneous tissue. Lipoma of the foot is rare and may cause serious discomfort and disturbance in gait. Due to the rarity of lipomas of the foot, they are usually misdiagnosed as other soft tissue lesions. Thus, accurate diagnosis is essential for improved quality of life. Magnetic resonance imaging is the state of the art in the proper diagnosis of the presence of necrotic areas, infiltration of surrounding tissues, and surgical planning. Method: A 24-year-old female presented with a soft mobile mass of fifteen years duration on the dorsal aspect of the foot, with splaying of the 4th and 5th toes. The lesion is reportedly slow-growing, increasing in size with age, extending laterally to the planter aspect of the 5th toe, and seldom painful. Plain x-rays showed a homogenous area of low density with scalloping of the 4th and 5th metatarsals. Ultrasound showed fatty infiltration that extends to the planta aspect and between metatarsals. Non-contrast enhanced magnetic resonance imaging (MRI) with T1W, T2W, fat suppression and proton-weighted density sequences was performed for further characterization of the lesion, to rule out any proliferation, and for surgical planning. Results: MRI showed a capsulated lesion with an area of isointensity, hyperintensity on T1W, hypointensity on T2W, a low signal on fat suppression, and thin encapsulated lesions with a lobular pattern, which were in line with a benign fatty tumour, lipoma. Conclusion: The prevalence of subcutaneous lipoma is high between the 4th and 6th decades in any anatomical region, but very rare among younger individuals. MRI is valuable in imaging soft tissue tumours due to its high soft tissue resolution and delineation to help distinguish between lipoma and malignant liposarcoma, and treatment planning.

Acknowledgements

The author would like to thank the patient for giving consent to use their images and to have their foot photographed for teaching and research purposes.

References

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Proc. Intl. Soc. Mag. Reson. Med. 32 (2024)
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DOI: https://doi.org/10.58530/2024/5144