Indian Journal of Nuclear Medicine

CASE REPORT
Year
: 2013  |  Volume : 28  |  Issue : 1  |  Page : 34--35

Skeletal muscle metastases as the initial manifestation of an unknown primary lung cancer detected on F-18 fluorodeoxyglucose positron emission tomography/computed tomography


Kanhaiyalal Agrawal1, Anish Bhattacharya1, Navneet Singh2, Chidambaram Natarajan Balasubramanian Harisankar1, Bhagwant Rai Mittal1,  
1 Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2 Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
Anish Bhattacharya
Department of Nuclear Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh - 160 012
India

Abstract

Skeletal muscle metastasis as the initial presentation of the unknown primary lung cancer is unusual. A 65-year-old male patient presented with pain and swelling of the right forearm. Fine needle aspiration of the swelling revealed metastatic squamous cell carcinoma. The patient underwent whole body F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to identify the site of the primary malignancy. The authors present PET/ CT images showing FDG-avid metastases to the skeletal muscles along with a previously unknown primary tumor in the right lung, in a patient presenting with initial muscular symptoms without any pulmonary manifestations.



How to cite this article:
Agrawal K, Bhattacharya A, Singh N, Harisankar CN, Mittal BR. Skeletal muscle metastases as the initial manifestation of an unknown primary lung cancer detected on F-18 fluorodeoxyglucose positron emission tomography/computed tomography.Indian J Nucl Med 2013;28:34-35


How to cite this URL:
Agrawal K, Bhattacharya A, Singh N, Harisankar CN, Mittal BR. Skeletal muscle metastases as the initial manifestation of an unknown primary lung cancer detected on F-18 fluorodeoxyglucose positron emission tomography/computed tomography. Indian J Nucl Med [serial online] 2013 [cited 2021 Jul 27 ];28:34-35
Available from: https://www.ijnm.in/text.asp?2013/28/1/34/116814


Full Text

 Introduction



Skeletal muscle metastasis as the initial presentation of an unknown primary lung cancer is unusual. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging is useful in the identification of primary in carcinoma of unknown origin. We describe a patient showing FDG-avid metastases to the skeletal muscles along with a previously unknown primary tumor in the right lung, in a patient presenting with initial muscular symptoms without any pulmonary manifestations.

 Case Report



A 65-year-old male presented with pain and swelling of the right forearm. Fine needle aspiration cytology of the swelling showed metastatic squamous cell carcinoma. The patient underwent a whole body F-18 FDG PET/CT to identify the site of the primary malignancy. Increased FDG avidity (standardized uptake value [SUV max ] 9.0) was detected in an irregular heterogeneously enhancing soft-tissue mass in the right paravertebral region in the upper lobe of the right lung with a focus of calcification within the mass [Figure 1]b and d, white arrow]. Abnormal FDG uptake was also noted in a presacral mass [Figure 1]c and e, the bulky left adrenal gland, several dorsal vertebrae and multiple lesions in the trapezius [Figure 1]b and d, red arrow], right brachioradialis [Figure 2], deltoid, and right external oblique muscles [Figure 3], suggestive of metastatic involvement. A diagnosis of primary squamous cell carcinoma of the lung was pathologically confirmed. The patient was treated with 4 cycles of chemotherapy, after which significant decrease in FDG uptake (SUV max = 5.1) was seen in the primary as well as the right brachioradialis muscle lesion (not shown here).{Figure 1}{Figure 2}{Figure 3}

 Discussion



Skeletal muscles are uncommon site of hematogenous metastases from epithelial neoplasms. Solitary muscle metastasis has been previously reported in lung cancer. [1] Tuoheti et al. found that only 4 patients (0.16%) among 2,557 patients with lung cancer developed metastasis to the skeletal muscle. [2] Most frequent muscle involvement is seen in the thigh, iliopsoas and paraspinous muscles. [3] Whole-body FDG PET/CT imaging is useful in detection of muscle metastases in lung cancer patients. [4] Multiple muscle metastases from lung cancer are rare, and FDG PET/CT imaging is useful in the identification of unsuspected metastatic sites. [5] Primary presentation of a skeletal muscle metastasis, such as in our case, remains an unusual occurrence. [3],[6],[7],[8],[9] The present case, where the initial presentation was of metastatic muscular involvement, highlights the role of FDG PET/CT in tracing the location of primary lung malignancy and unsuspected sites of multiple muscle metastases in a patient with muscle metastases of unknown primary.

References

1Di Giorgio A, Sammartino P, Cardini CL, Al Mansour M, Accarpio F, Sibio S, et al. Lung cancer and skeletal muscle metastases. Ann Thorac Surg 2004;78:709-11.
2Tuoheti Y, Okada K, Osanai T, Nishida J, Ehara S, Hashimoto M, et al. Skeletal muscle metastases of carcinoma: A clinicopathological study of 12 cases. Jpn J Clin Oncol 2004;34:210-4.
3Kaira K, Ishizuka T, Yanagitani N, Sunaga N, Tsuchiya T, Hisada T, et al. Forearm muscle metastasis as an initial clinical manifestation of lung cancer. South Med J 2009;102:79-81.
4Bhargava P, Verstovsek G, Stair M, Vollink J. Metastasis to psoas muscle detected by F-18 FDG PET-CT imaging. Clin Nucl Med 2008;33:723-4.
5Yilmaz M, Elboga U, Celen Z, Isik F, Tutar E. Multiple muscle metastases from lung cancer detected by FDG PET/CT. Clin Nucl Med 2011;36:245-7.
6Loziæ AA, Silconi ZB, Misljenoviæ N. Metastases to rare locations as the initial manifestation of non-small cell lung cancer: Two case reports. Coll Antropol 2010;34:609-12.
7Ruzzini L, Rigato P, Ruzzini S. Intramuscular forearm metastasis as an initial presentation of bronchial adenocarcinoma. Acta Orthop Belg 2009;75:129-32.
8Singh A, Pandey KC, Pant NK. Cavitary mucoepidermoid carcinoma of lung with metastases in skeletal muscles as presenting features: A case report and review of the literature. J Cancer Res Ther 2010;6:350-2.
9Razak AR, Chhabra R, Hughes A, England S, Dildey P, McMenemin R. Muscular metastasis, a rare presentation of non-small-cell lung cancer. MedGenMed 2007;9:20.