Ileo-psoas muscle metastasis from pulmonary carcinoma

A Tuladhar,Rb Basnet,S Parajuli

doi:10.3126/jpn.v2i3.6033

Abstract

Metastatic disease to muscle is rare and may be misdiagnosed when it is the presenting symptom, particularly in the absence of a known primary tumor. Skeletal muscle metastasis as a mode of presentation of primary lung cancer is an unusual phenomenon. Here, we report a case of ileo-psoas muscle metastasis from lung cancer as the initial clinical manifestation in a 58 year-old male with a personal history of heavy smoking. Excisional biopsy of the mass in the ileo-psoas muscle revealed metastatic adenocarcinoma. Computed tomography scan of the chest for a primary search was done and found to be pulmonary carcinoma. DOI: http://dx.doi.org/10.3126/jpn.v2i3.6033 JPN 2012; 2(3): 251-253

Highlights

Skeletal muscle metastasis from lung cancer is rare
The true incidence of skeletal muscle metastasis of adenocarcinoma of lung remains unknown, but an autopsy series suggests that its incidence could be as low as 0.8% despite of the fact that skeletal muscle accounts for nearly 50% of the total body weight and is characterized by rich blood supply.[6]
The constant movement of skeletal muscles which may represent a difficult condition for the implantation and growth of metastatic cells under the high tissue pressure related to the exercise-associated increase of blood flow, the local production of lactic acid which would create an unfavorable environment for metastatic cell growth, the inhibition of cell invasion by protease inhibitors located in the basement membrane, and the antitumor activity of lymphocytes or natural killer cells within the skeletal muscle.[6,7]

Summary

INTRODUCTION

Skeletal muscle metastasis from lung cancer is rare. Skeletal muscle metastasis as a mode of presentation of primary lung cancer is an unusual phenomenon. The FNA smears showed small groups and singly dispersed malignant looking epithelial cells admixed with clusters of fibroblasts against a haemorrhagic background Computed Tomography (CT) scan and Magnetic resonant imaging (MRI) revealed a possibility of a primary malignant neoplasm on the ileopsoas muscle seen eroding the surrounding bones. Cut section of the mass showed solid grayish-white firm tissue with foci of haemorrhage at the periphery Microscopic examination revealed extensive infiltration of the muscle with atypical tumour cells arranged in numerous small, irregular glands lined by hyperchromatic enlarged nuclei. CT scan of the chest revealed a lesion measuring 2×1 cm in the right upper lobe towards the periphery suggestive of adenocarcinoma

DISCUSSION

Findings

CONCLUSION