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Nodular cystic fat necrosis: a distinctive rare soft-tissue mass

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Abstract

We report the case of a 34-year-old female who was evaluated for a right lower extremity soft-tissue mass, found to be a large cystic lesion bound by fibrous tissue containing innumerable, freely mobile nodules of fat. Her presentation suggested the diagnosis of nodular cystic fat necrosis (NCFN), a rare entity that likely represents a morphological subset of fat necrosis potentially caused by vascular insufficiency secondary to local trauma. Her lesion was best visualized using MRI, which revealed characteristic imaging features of NCFN including nodular lipid-signal foci that suppress on fat-saturated sequences, intralesional fluid with high signal intensity on T2-weighted imaging, and a contrast-enhancing outer capsule with low signal intensity on T1-weighted imaging. Ultrasound imaging offered the advantage of showing mobile hyperechogenic foci within the anechoic cystic structure, and the lesion was otherwise visualized on radiography as a nonspecific soft-tissue radiopacity. She was managed with complete surgical excision with pathologic evaluation demonstrating, similar to the radiologic features, innumerable free-floating, 1–5 mm, smooth, nearly uniform spherical nodules of mature fat with widespread necrosis contained within a thick fibrous pseudocapsule. Follow-up imaging revealed no evidence of remaining or recurrent disease on postoperative follow-up MRI. The differential diagnosis includes lipoma with fat necrosis, lipoma variant, atypical lipomatous tumor, and a Morel-Lavallée lesion. There is overlap in the imaging features between fat necrosis and both benign and malignant adipocytic tumors, occasionally making this distinction based solely on imaging findings challenging. To our knowledge, this is the largest example of NCFN ever reported.

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References

  1. Hurt MA, Santa Cruz DJ. Nodular-cystic fat necrosis: A reevaluation of the so-called mobile encapsulated lipoma. J Am Acad Dermatol. 1989;21:493–8.

    Article  PubMed  CAS  Google Scholar 

  2. Przyjemski CJ, Schuster SR. Nodular-cystic fat necrosis. J Pediatr. 1977;91:605–7.

    Article  PubMed  CAS  Google Scholar 

  3. Ban M. Nodular-cystic fat necrosis-A review of 147 Japanese patients. J Dermatol Res. 2016;1:65–8.

    Article  Google Scholar 

  4. Kiryu H, Rikihisa W, Furue M. Encapsulated fat necrosis – A clinicopathological study of 8 cases and a literature review. J Cutan Pathol. 2000;27:19–23.

    Article  PubMed  CAS  Google Scholar 

  5. Oh C-W, Kim K-H. A case of nodular cystic fat necrosis: The end stage lesion showing calcification and lipomembranous changes. J Dermatol. 1998;25:616–21.

    Article  PubMed  CAS  Google Scholar 

  6. Pujol RM, Wang C-Y, Gibson LE, Daniel Su WP. Lipomembranous changes in nodular-cystic fat necrosis. J Cutan Pathol. 1995;22:551–5.

    Article  PubMed  CAS  Google Scholar 

  7. Weaver J, Downs-Kelly E, Goldblum JR, Turner S, Kulkarni S, Tubbs RR, et al. Fluorescence in situ hybridization for MDM2 gene amplification as a diagnostic tool in lipomatous neoplasms. Mod Pathol. 2008;21:943–9.

    Article  PubMed  CAS  Google Scholar 

  8. De Wilde R, Hautekiet A, Geers S, Bossche LV, De Muynck M. Ultrasonographic presentation of nodular cystic fat necrosis after a low-velocity trauma: A case report. J Rehabil Med-Clin Commun. 2022;5:jrmcc00083.

    Article  Google Scholar 

  9. Nakamura Y, Ishizuki S, Ishitsuka Y, Watanabe R, Saito A, Furuta J, et al. Multiple, lipid-containing, subcutaneous cysts suspected of end-stage nodular cystic fat necrosis. J Dermatol. 2020;47:e85–7.

    Article  PubMed  Google Scholar 

  10. Yi-Hsin H, Ya-Wen H, Yi-Chin S. Multiple floating fat balls on the right lower leg. Indian J Dermatol Venereol Leprol. 2011;77:731.

    Article  PubMed  Google Scholar 

  11. Gocmen R, Kerimoglu U. An unusual appearance of traumatic fat necrosis: Floating fat balls. European Journal of Radiology Extra. 2008;66:e43–5.

    Article  Google Scholar 

  12. Burkholz KJ, Roberts CC, Lidner TK. Posttraumatic pseudolipoma (fat necrosis) mimicking atypical lipoma or liposarcoma on MRI. Radiol Case Rep. 2007;2:56–60.

    Article  PubMed  Google Scholar 

  13. Kransdorf MJ, Murphey MD. Radiologic evaluation of soft-tissue masses. AJR Am J Roentgenol. 2000;175:575–87.

    Article  PubMed  CAS  Google Scholar 

  14. Einarsdottir H, Söderlund V, Larson O, Jenner G, Bauer HCF. MR imaging of lipoma and liposarcoma. Acta Radiol SAGE Publications. 1999;40:64–8.

    Article  CAS  Google Scholar 

  15. Sundaram M, McLeod RA. MR imaging of tumor and tumorlike lesions of bone and soft tissue. AJR Am J Roentgenol Ray Soc. 1990;155:817–24.

    Article  CAS  Google Scholar 

  16. Bancroft LW, Kransdorf MJ, Peterson JJ, O’Connor MI. Benign fatty tumors: Classification, clinical course, imaging appearance, and treatment. Skelet Radiol. 2006;35:719–33.

    Article  Google Scholar 

  17. López JA, Saez F, Alejandro Larena J, Capelastegui A, Martín JI, Canteli B. MRI diagnosis and follow-up of subcutaneous fat necrosis. J Magn Reson Imaging. 1997;7:929–32.

    Article  PubMed  Google Scholar 

  18. Galant J, Martí-Bonmatí L, Sáez F, Soler R, Alcalá-Santaella R, Navarro M. The value of fat-suppressed T2 or STIR sequences in distinguishing lipoma from well-differentiated liposarcoma. Eur Radiol. 2003;13:337–43.

    Article  PubMed  CAS  Google Scholar 

  19. Canteli B, Saez F, de los Ríos A, Alvarez C. Fat necrosis. Skeletal Radiol. 1996;25:305–7.

    Article  PubMed  CAS  Google Scholar 

  20. Tsai TS, Evans HA, Donnelly LF, Bisset GS, Emery KH. Fat necrosis after trauma: A benign cause of palpable lumps in children. AJR Am J Roentgenol Ray Soc. 1997;169:1623–6.

    Article  CAS  Google Scholar 

  21. Chan LP, Gee R, Keogh C, Munk PL. Imaging features of fat necrosis. AJR Am J Roentgenol Ray Soc. 2003;181:955–9.

    Article  Google Scholar 

  22. Drevelegas A, Pilavaki M, Chourmouzi D. Lipomatous tumors of soft tissue: MR appearance with histological correlation. Eur J Radiol. 2004;50:257–67.

    Article  PubMed  CAS  Google Scholar 

  23. Gupta P, Potti TA, Wuertzer SD, Lenchik L, Pacholke DA. Spectrum of fat-containing soft-tissue masses at MR imaging: The common, the uncommon, the characteristic, and the sometimes confusing. Radio Graphics. 2016;36:753–66.

    Google Scholar 

  24. Ahlawat S, Fritz J, Morris CD, Fayad LM. Magnetic resonance imaging biomarkers in musculoskeletal soft tissue tumors: Review of conventional features and focus on nonmorphologic imaging. J Magn Reson Imaging. 2019;50:11–27.

    Article  PubMed  Google Scholar 

  25. Yee EJ, Stewart CL, Clay MR, McCarter MM. Lipoma and its doppelganger: The atypical lipomatous tumor/well-differentiated liposarcoma. Surg Clin N Am. 2022;102:637–56.

    Article  PubMed  Google Scholar 

  26. Shannon BA, Ahlawat S, Morris CD, Levin AS, Fayad LM. Do contrast-enhanced and advanced MRI sequences improve diagnostic accuracy for indeterminate lipomatous tumors? Radiol Med. 2022;127:90–9.

    Article  PubMed  Google Scholar 

  27. Andaç N, Baltacıoǧlu F, Çimşit NÇ, Tüney D, Aktan Ö. Fat necrosis mimicking liposarcoma in a patient with pelvic lipomatosis: CT findings. Clin Imaging. 2003;27:109–11.

    Article  PubMed  Google Scholar 

  28. Diviti S, Gupta N, Hooda K, Sharma K, Lo L. Morel-Lavallee lesions-Review of pathophysiology, clinical findings, imaging findings and management. J Clin Diagn Res. 2017;11:TE01–4.

    PubMed  PubMed Central  Google Scholar 

  29. Vanhegan IS, Dala-Ali B, Verhelst L, Mallucci P, Haddad FS. The Morel-Lavallée lesion as a rare differential diagnosis for recalcitrant bursitis of the knee: Case report and literature review. Case Rep Orthop. 2012;2012:593193.

    PubMed  PubMed Central  Google Scholar 

  30. Bonilla-Yoon I, Masih S, Patel DB, White EA, Levine BD, Chow K, et al. The Morel-Lavallée lesion: Pathophysiology, clinical presentation, imaging features, and treatment options. Emerg Radiol. 2014;21:35–43.

    Article  PubMed  Google Scholar 

  31. Mellado JM, Bencardino JT. Morel-Lavallée lesion: Review with emphasis on MR imaging. Magn Reson Imaging Clin N Am. 2005;13:775–82.

    Article  PubMed  Google Scholar 

  32. Mellado JM, del Palomar LP, Díaz L, Ramos A, Saurí A. Long-standing Morel-Lavallée lesions of the trochanteric region and proximal thigh: MRI features in five patients. AJR Am J Roentgenol Ray Soc. 2004;182:1289–94.

    Article  CAS  Google Scholar 

  33. Masarapu V, Wang PS, Gorbachova T. Slow-growing buttock mass after failure of incorporation of autologous fat transfer for gluteal augmentation: Ultrasound and MRI features. Skelet Radiol. 2020;49:1669–75.

    Article  Google Scholar 

  34. Kontoes P, Gounnaris G. Complications of fat transfer for breast augmentation. Aesthet Plast Surg. 2017;41:1078–82.

    Article  Google Scholar 

  35. Lin DJ, Wong TT, Ciavarra GA, Kazam JK. Adventures and misadventures in plastic surgery and soft-tissue implants. RadioGraphics Radiol Soc North Am. 2017;37:2145–63.

    Google Scholar 

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Correspondence to Laura M. Fayad.

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Shivani Ahlawat: Neurofibromatosis Therapeutic Acceleration Program. Laura M. Fayad: NIH R61, Neurofibromatosis Therapeutic Acceleration Program, Johns Hopkins University. Minsoo Kim, John M. Gross, and Adam S. Levin declare no competing interests.

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Kim, M., Gross, J.M., Ahlawat, S. et al. Nodular cystic fat necrosis: a distinctive rare soft-tissue mass. Skeletal Radiol 53, 583–588 (2024). https://doi.org/10.1007/s00256-023-04426-0

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  • DOI: https://doi.org/10.1007/s00256-023-04426-0

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