Iranian Journal of Nuclear Medicine

Iranian Journal of Nuclear Medicine

Unusual metastatic pattern in male breast invasive ductal carcinoma: Cutaneous and skeletal muscle metastases identified on [18F]FDG PET/CT

Articles in Press

Document Type : Case Report

Authors
Mahsa Sheikhnezami 1
Amin Saber Tanha 2
Amirreza Khorasanchi 1
Zakieh Nasiri 1
Sara Shakeri 1
Ramin Sadeghi 2
1 Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran
2 Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
10.22034/irjnm.2026.130532.1762
Abstract
A 67‑year‑old man presented with multiple cutaneous nodules involving the face, trunk, and extremities. Biopsy of the largest lesion on the upper anterior chest wall demonstrated metastatic carcinoma of unknown primary origin. [18F]FDG PET/CT demonstrated an unusual metastatic pattern with diffuse hypermetabolic cutaneous, subcutaneous, muscular, and osseous involvement. Among these lesions, a hypermetabolic right breast nodule was identified and targeted for biopsy, establishing the diagnosis of triple-negative invasive ductal carcinoma. This case represents an exceedingly rare presentation of male breast cancer with extensive skin and muscle metastases. It highlights the critical diagnostic value of [18F]FDG PET/CT in resolving unknown-primary malignancies and guiding definitive tissue sampling in atypical metastatic disease.
Keywords
Malignancy workup
Oncology
Dermatology
Triple-negative breast cancer
Theranostics
Subjects
  1. Zheng G, Leone JP. Male breast cancer: an updated review of epidemiology, clinicopathology, and treatment. J Oncol. 2022 May 24;2022:1734049.
  2. Pullen RL Jr. Breast cancer in males. Nursing. 2025 Mar 1;55(3):18-26.
  3. Graf M, Gerken M, Klinkhammer-Schalke M, Schrodi S, Pauer A, Geiss K, Ortmann O, Sturm-Inwald EC. Clinical, therapeutic and prognostic differences between male and female patients with breast cancer-a comparison of 2510 men and 307,634 women in a registry-based study in Germany. J Cancer Res Clin Oncol. 2025 Jun 3;151(6):181.
  4. Ray SK, Mukherjee S. Clinical aspect of male breast cancer: a burgeoning and unaddressed issue. Mol Biol Rep. 2025 May 13;52(1):452.
  5. Dent R, Hanna WM, Trudeau M, Rawlinson E, Sun P, Narod SA. Pattern of metastatic spread in triple-negative breast cancer. Breast Cancer Res Treat. 2009 May;115(2):423-8.
  6. Li Y, Su P, Wang Y, Zhang H, Liang Y, Zhang N, Song X, Li X, Li J, Yang Q. Impact of histotypes on preferential organ-specific metastasis in triple-negative breast cancer. Cancer Med. 2020 Feb;9(3):872-881.
  7. Qavi Q, Alkistawi F, Kumar S, Ahmed R, Saad Abdalla Al-Zawi A. Male triple-negative breast cancer. cureus. 2021 Apr 18;13(4):e14542.
  8. Araújo E, Barbosa M, Costa R, Sousa B, Costa V. A first sign not to be missed: cutaneous metastasis from breast cancer. Eur J Case Rep Intern Med. 2020 Jan 8;7(1):001356.
  9. Salemis NS. Skeletal muscle metastasis from breast cancer: management and literature review. Breast Dis. 2015;35(1):37-40.
  10. Kim YW, Seo KJ, Lee SL, Kwon KW, Hur J, An HJ, Ko YH, Kim JS, Won HS. Skeletal muscle metastases from breast cancer: two case reports.  J Breast Cancer. 2013 Mar 1;16(1):117-21.
  11. Ogiya A, Takahashi K, Sato M, Kubo Y, Nishikawa N, Kikutani M, Tadokoro Y, Tanaka K, Uematsu T, Watanabe J, Kasami M. Metastatic breast carcinoma of the abdominal wall muscle: a case report. Breast Cancer. 2015 Mar;22(2):206-9.
  12. Khandelwal AR, Takalkar AM, Lilien DL, Ravi A. Skeletal muscle metastases on FDG PET/CT imaging. Clin Nucl Med. 2012 Jun;37(6):575-9.
  13. Surov A, Hainz M, Holzhausen HJ, Arnold D, Katzer M, Schmidt J, Spielmann RP, Behrmann C. Skeletal muscle metastases: primary tumours, prevalence, and radiological features. Eur Radiol. 2010 Mar;20(3):649-58.
  14. Ong N, George M, Dutta R, Ng CH. CT imaging features of skeletal muscle metastasis. Clin Radiol. 2019 May;74(5):374-7.
  15. Saunders AAE, Thomson RE, Goodman CA, Anderson RL, Gregorevic P. Striated muscle: an inadequate soil for cancers. Cancer Metastasis Rev. 2024 Dec;43(4):1511-27.
  16. Rafiei Z, Saber Tanha A, Tayyebi Meibodi N, Zahed Anaraki S, Askari E. Cutaneous and subcutaneous prostate-specific membrane antigen-avid lesions. Clin Nucl Med. 2025 Mar 1;50(3):e164-5.
  17. Flindris S, Margioula-Siarkou C, Margioula-Siarkou G, Gouta C, Styliara E, Navrozoglou I, Petousis S, Dinas K. Cutaneous metastasis of triple negative breast cancer: a case report and review of literature. Cureus. 2025 Mar 2;17(3):e79926.
  18. Ajai Mokan Dasan SL, Pandey N, Sukhoroslov M, Rudikoff D, Mazhar N. Triple-negative male breast cancer presenting as cutaneous metastasis: a diagnostic rarity. Case Rep Oncol Med. 2025 Nov 20;2025:4393243.
  19. Hugentobler A, Gilbeau L, Talbot JN, Gauthé M. 18F-Fluorocholine PET/CT of incidental male breast cancer. Clin Nucl Med. 2017 Jan;42(1):e56-7.
  20. Gill HS, Tade F, Greenwald DT, Yonover PM, Savir-Baruch B. Metastatic male breast cancer with increased uptake on 18F-Fluciclovine PET/CT scan. Clin Nucl Med. 2018 Jan;43(1):23-4.
  21. Sindoni A, Perin T, Borsatti E. Re: 18F-Fluorocholine PET/CT of incidental male breast cancer. Clin Nucl Med. 2018 Jan;43(1):75-6.
  22. McEachen JC, Kuo PH. Male primary breast cancer found on FDG-PET/CT. Clin Nucl Med. 2008 Sep;33(9):630-2.
  23. Hooda Z, Lu Y, Mehran RJ, Moran C, Barcenas CH. Rosai-Dorfman disease mimicking metastasis to the spleen from breast cancer. Clin Nucl Med. 2025 May 1;50(5):450-1.
  24. Piciu A, Piciu D, Polocoser N, Kovendi AA, Almasan I, Mester A, Morariu DS, Cainap C, Cainap SS. Diagnostic performance of F18-FDG PET/CT in male breast cancers patients. Diagnostics (Basel). 2021 Jan 13;11(1):119
Iranian Journal of Nuclear Medicine

Articles in Press, Accepted Manuscript
Available Online from 02 November 2026