Journal of Cancer Research and Therapeutics Medknow Publications on behalf of the Association of Radiation Oncologists of India (AROI) ISSN: 0973-1482 EISSN: 1998-4138 Vol. 6, Num. 3, 2010, pp. 350-352

Journal of Cancer Research and Therapeutics, Vol. 6, No. 3, July-September, 2010, pp. 350-352

Case Report

Cavitary mucoepidermoid carcinoma of lung with metastases in skeletal muscles as presenting features: A case report and review of the literature

Abhishek Singh, Kailash C Pandey, Nirdosh K Pant

Department of Radiotherapy and Clinical Oncology, Swami Ram Cancer Hospital and Research Institute, Government Medical College, Haldwani, Nainital, Uttarakhand, India

Correspondence Address:Abhishek Singh, Department of Radiotherapy and Clinical Oncology, Swami Ram Cancer Hospital and Research Institute, Government Medical College, Haldwani, Nainital, Uttarakhand, India, hivneg@gmail.com

Code Number: cr10084

PMID: 21119274

DOI: 10.4103/0973-1482.73363

Abstract

Keywords: Lung carcinoma, mucoepidermoid carcinoma, skeletal muscle metastases

Introduction

Mucoepidermoid carcinomas (MECs) of lung are rare neoplasms comprising 0.1-0.2% of primary lung cancers. They mimic the distinct morphology of same tumors found in salivary glands first described by Stewart et al. in 1945 and were earlier thought to occur only in salivary glands. ^[1] Later studies showed primary in bronchus, esophagus, lacrimal glands, pancreas, thymus and thyroid gland. As a disease entity, it is unique for the infrequency with which it occurs, and its variable clinical expression. ^[2],[3],[4] The cavitary lesion in MEC of lung is rare. Initially described as benign adenoma, it is now considered to be a malignant epithelial tumor with reports of metastases to regional lymph nodes, other parts of the lung and distant organs. Here, we report, to the best of our knowledge, the only case of MEC of lung with metastases to skeletal muscles as presenting feature.

Case Report

A 54-year-old male presented with multiple hard lumps developing and gradually increasing in size in right thigh, right groin and left arm for a period of one year, which were ignored by patient until the one in groin became painful and he developed high grade fever. On examination, patient had a hard painless lump approximately 3 × 3 cm in size arising from muscles of anterior compartment of thigh; two similar lumps of size approximately 2 × 2.5 cm and 1 × 1 cm were palpable in left arm biceps muscle; one such tender lump with cystic areas and signs of inflammation was present in right groin. On auscultation, bronchial sounds were heard in right infra-scapular area with occasional wheeze. His total leucocyte counts and C-reactive proteins were found to be raised while liver and renal function tests were within normal limits. Fine needle aspiration cytology from the lumps was suggestive of metastatic mucoepidermoid carcinoma [Figure - 1]. Computed tomography revealed multiple enlarged necrotic lymphnodes in the subcarinal and right hilar region. A cavitary lesion was seen along the pleura- pulmonary interface in the region of the right postero-lateral costophrenic sulcus [Figure - 2]. Necrotic lymphnodes were seen within the inguinal canal. Respiratory function tests showed obstructive respiratory changes. The tumor markers serum carcinoembryonic antigen, cancer antigen 19.9 and urinary 5-hydroxyindoleacetic acid were all within normal limits. Bronchoscopy revealed partial effacement of lower lobe and middle lobe bronchi by a polypoid growth with histopathology in favor of high grade MEC of lung [Figure - 3]. Patient was administered two cycles of systemic chemotherapy with cisplatin and paclitaxel. An increase in size of muscle lesions was observed after two cycles though patient had symptomatic relief. Second line chemotherapy was started with cisplatin, adriamycin and 5-flourouracil. Reduction in size was noted after four cycles but patient′s general condition deteriorated. Targeted therapy with geftinib was started. Despite all treatments, patient′s condition deteriorated and he died seven months after diagnosis.

Discussion

MECs are malignant tumors that are composed of squamous epithelial cells mixed with mucin producing cells. MECs of tracheo-bronchial tree were first reported by Smetana et al. in 1952. ^[5] Earlier believed to be benign, dissemination was later described by Ozlu et al. in 1961. ^[6] Both lymphangitic and hematogenous metastases have been demonstrated. The usual sites of metastases are the regional lymph nodes (48%), other portions of the lung (25%), bone marrow (25%), distant lymph nodes (18%), adrenal gland (14%), brain (14%), and skin (14%). Few cases have been reported of metastases to kidney, pleura, pericardium, mediastinum, duramater, and gastro-intestinal tract. ^{[2],[3],[6],[7]} No case of metastasis to skeletal muscles has been reported so far. MECs are divided into high grade and low grade according to their histological and ultrastructural characteristics in an attempt to predict malignant potential. Necrosis and mitoses were found only in high grade MEC. The metastatic potential of low grade type is extremely low, and death is very unusual. The high grade type has high metastatic potential and histology of metastases may indicate even more aggressive features than the primary. MECs are seen in a broad age range including childhood but mostly in fifth decades. Although some studies have reported a male pre-dominance for this tumor type, most studies have failed to confirm this. It has been found that low grade MECs occur more frequently in younger patients and has female predominance. Smoking habit is not associated with risk of developing this tumor. The patient reported here too was a non smoker.

Most patients present with cough and hemoptysis followed by recurrent pneumonia and fever. Few patients with high grade tumor may present with sustained chest pains. This patient′s presentation was unusual as he had no symptoms or complaints due to primary lung lesion and presented with metastatic lumps in skeletal muscles and distant lymphnodes. Presence of cavitary lesion is also unusual. One case of cavitary presentation of MEC of lung has been reported by Tanvetyanon et al. ^[7]

Surgery is the treatment of choice for patients with MECs if the lesion is resectable. Low grade tumors should be removed completely for best results. Neodymium yttrium aluminum garnet (Nd-YAG) laser has been used successfully in two cases by Li et al. ^[8] Adjuvant treatment is not suggested for patients with low grade MECs. Re-excision is better option for margin positive cases. Adjuvant chemotherapy or radiotherapy can be considered for incomplete resection if re-excision is not possible or in advanced disease. Combination chemotherapies of platins, taxanes, gemcitabine, adriamycin and pemetrexed; targeted therapy with geftinib and erlotinib have been used. High grade tumors have reported to be fatal in sixteen to twenty seven months after diagnosis. ^[9],[10] Adjuvant therapy was less effective for the patients with high grade tumors. The prognostic factors include histological tumor grading, stage and achievement of surgical intervention.

Conclusion

MEC of the lung is a rare type of malignancy distinctive for the frequency of its occurrence and variable presentation. Surgical intervention is the treatment of choice for all resectable tumors. Combination chemotherapies or targeted therapies can be tried in patients with distant metastasis but with varied results. Metastasis to skeletal muscles though rare may be the initial and only manifestation of the tumor and requires high index of suspicion on part of clinician.

References

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