Gen Thorac Cardiovasc Surg (2011) 59:382–384 DOI 10.1007/s11748-010-0670-3
CASE REPORT
Non-small-cell lung cancer: unusual presentation in the gluteal muscle Bassel Suffian Al-Alao, MD · Jennifer Westrup, MD Maher Nicolas Shuhaibar, MD
Received: 13 March 2010 / Accepted: 5 July 2010 © The Japanese Association for Thoracic Surgery 2011
Abstract Lung cancer is one of the most commonly diagnosed cancers in both men and women worldwide. It is also one of the most common forms of cancer in Ireland, accounting for about 20% of all deaths from cancer each year. Early detection of lung cancer is infrequent, and most cases are not diagnosed and treated until they are at an advanced stage. Distant metastases in lung cancer commonly involve the adrenal glands, liver, bones, and central nervous system; they are only rarely seen in the skeletal system. We report a rare case of metastasis to the gluteal muscle as the initial presentation of lung cancer. Key words Lung cancer · Gluteal mass · Metastasis · Skeletal muscles
Introduction Skeletal muscle is a highly unusual site for metastases from any cancer, and skeletal muscle metastases from lung carcinoma are exceedingly rare. Because of the lung’s intrathoracic location, a casual discovery of lung cancer with an absence of symptoms occurs more frequently. Thus, lung carcinomas often remain clinically
B.S. Al-Alao (*) · M.N. Shuhaibar Department of Cardiothoracic Surgery, UPMC Beacon Hospital, Sandyford, Dublin 18, Ireland Tel. +353-1-292-0500; Fax +353-1-292-0501 e-mail:
[email protected] J. Westrup Department of Oncology, UPMC Beacon Hospital, Sandyford, Dublin, Ireland
silent for some time until local invasion or metastatic spread results in symptoms. The present communication describes a 60-year-old man who presented with a unilateral lump in the buttock and recent hip pain, with no associated systematic symptoms. After investigation, and unexpectedly, a gluteal muscle biopsy showed metastatic lung adenocarcinoma.
Case description A 60-year-old man with 30-pack-year smoking history presented to his general practitioner (GP) with ongoing right hip pain for the last 8 weeks. A subsequent thorough evaluation revealed a normal physical examination (no obvious mass on inspection and palpation, negative Trendelenberg test, normal range of motion) and no evidence of abnormal findings on baseline investigations (plain radiography of the hips and lumbosacral spine, full blood count and erythrocyte sedimentation rate, biochemistry tests, rheumatoid factor assay). He presented again with recent development of a lump in the right gluteal region that was gradually increasing in size and required urgent referral to our medical center. Physical examination revealed an ill-defined, large mass (tennis ball size) that was tender to touch; it was firmly attached to the right gluteal muscle underneath and detached from the skin above it. There was a decrease in the range of motion of the right hip. Thorough systematic examination showed no obvious peripheral lymphadenopathy in the axilla or groins. Computed tomography (CT) of the chest revealed a 2.5-cm cavitating mass in the left upper lobe and necroticappearing lymph nodes in the left hilar region and the aortopulmonary window (Fig. 1a). No other
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Fig. 1 a Computed tomography (CT) of the thorax shows a lesion (arrow) in the left upper lobe. b Magnetic resonance imaging (MRI) of the spine shows a metastasis (arrow) at T10. c CT of the pelvis shows a gluteal mass (arrow). d MRI of the pelvis shows the gluteal mass (arrow)
intrapulmonary pathology was identified. CT of the abdomen and pelvis identified multiple low-density masses in the liver consistent with metastasis along with enlarged nodes in the retroperitoneum and the right internal and external iliac stations. Multiple soft tissue masses were demonstrated in the obturator and gluteal muscles (Fig. 1c). Magnetic resonance imaging (MRI) of the pelvis with gadolinium confirmed the above findings and raised the possibilities of small-cell lung cancer, melanoma, or prostate cancer in a differential diagnosis (Fig. 1b,d). CT and MRI of the brain with gadolinium revealed a 12-mm solitary enhancing metastasis in the right frontoparietal lobe. Whole-body nuclear medicine isotope bone scans revealed a deposit in the 10th thoracic vertebral body. Fibroadipose tissue infiltrated by poorly differentiated carcinoma with papillary features consistent with lung primary was diagnosed in an ultrasonography (US)-guided fine-needle core biopsy specimen from the gluteal mass; it was confirmed by immunohistochemistry positive staining of TTF-1 (Fig. 2). The lesion was staged as T1N2M1 (stage IV), and the patient was referred to
the oncology service for palliative chemoradiation treatment. A palliative course of radiation therapy was delivered to the right hemicerebellum and T10 as initial treatment and as part of six-cycle therapy. The patient unfortunately developed spinal cord compression, which required steroids and cessation of radiotherapy treatment. Approximately 50% relief of pain on morphine analgesia was achieved, and the patient maintained a stable neurological condition during the course of his admission. He died shortly before the planned hospital discharge.
Discussion Lung cancer is one of the leading causes of cancer death in both men and women worldwide. Most patients present at an advanced stage and hence, despite developments in diagnosis and treatment, the mortality rate remains high. Distant metastases of lung cancer commonly involve the liver (33%–40%), adrenal glands
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Fig. 2 Left Histological study shows fibroadipose tissue infiltrated by poorly differentiated carcinoma with papillary features consistent with primary lung cancer. (H&E, ×40) Right Immunohistochemistry shows positive staining of TTF-1. (×20)
(18%–38%), brain (15%–43%), bone (19%–33%), kidney (16%–23%), and abdominal lymph nodes (29%).1 Metastases to skeletal muscle from primary lung cancer are a rare event, with few reports in the literature.2,3 Although solid metastases to the gluteal muscle from various primaries have been described in case reports, this has not been the case for metastatic lung cancer. The only form of lung metastasis to the gluteal region has been reported as an abscess.4 Intramuscular metastasis of malignant tumors is considered to be rare. The frequency of intramuscular metastasis, based on autopsy findings, was reported by Willis5 to be 0.8% in patients with cancer and by Berge and Lundberg6 to be 1% in patients with lung cancer. Various physiological factors, such as tissue blood flow and pressure and metabolism, have been cited as the possible reasons metastases to skeletal muscle are rare. According to some studies, the presence of proteases and certain inhibitors in muscle tissue are responsible for blocking tumor invasion and growth.7 Each malignant tumor has its own intrinsic distribution pattern of metastatic lesions, and the organ specificity of tumor metastasis has been increasingly recognized.8 Seed-and-soil and circulation hypotheses have been proposed to explain the organ specificity for metastasis. The environments favorable for the growth of tumor cells in a target organ and the ease with which tumor cells reach the target organ are due, respectively, to the vasculature and blood supply in the former and latter situations. The primary mode of metastasis to skeletal muscles is thought to be hematogenous. The low incidence of skeletal muscle metastasis may be explained by mechanical destruction of tumor cells by muscle movement, prevention of the settlement of tumor cells due to changes in the blood flow and high metabolic activity, and inhibition of tumor cell proliferation by lactic acid, proteinase, and low pH in muscle.2,8 This may explain the fact that
by the time the metastasis became evident in the muscle of our patient he had widespread metastasis to the brain, liver, and spine. There is no consensus on the optimal treatment strategy for skeletal muscle metastases as it may be the endstage presentation of lung cancer. Although radiotherapy, chemotherapy, and/or excision may be implemented for local control or palliation, it is doubtful if any of these measures can achieve disease modification or contribute to a patient’s survival, as was evident in this case. Our patient was offered palliative radiotherapy in view of the systemic nature of his disease but died within 10 days after the diagnosis.
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