Adenocarcinoma of the lung metastatic to the psoas muscle

Abstract

Hematogenous metastasis to the psoas muscle is rare, and the resulting clinical symptoms may mimic psoas abscess or hemorrhage. When the clinical history is not specific, CT is important in documenting the presence of a psoas mass and providing biopsy guidance for histologic diagnosis. Only three previously reported cases have been related to a primary carcinoma of the lung.

Distant Soft Tissue Metastases: A Series of 30 New Patients and 91 Cases From the Literature

“…Psoas involvement by metastastic disease is frequently confused with psoas abscess or hematoma, both clinically and radiographically. 4,21,27,28,38 Both thigh and shoulder involvement have also been confused with abscess formation. 55 Pulsatile or otherwise vascular subcutaneous renal metastases have been confused clinically with hemangiomas or varicosities.…”

“…3,4,[7][8][9][10][11][12]14,15,20,22,24,26,27,29,30,32,34,36,37,39,40,42,43,44,45,48,49,53,55 Because the currently reported group of 30 new patients did not include any patients whose primary tumors were of renal or colon origin, the possibility remains that cases of renal and colon metastases to soft tissue are overrepresented in the literature. This possibility seems especially likely given the relatively prolonged survival for the vast majority of those renal cell metastases reported.…”

“…1,7,10,11,15,20,24,25,[27][28][29][30][31]35,42,44,46,48,52,55 Lung tumors metastastic to the soft tissue most commonly present in this fashion with an occult, previously unrecognized pulmonary primary. This finding is consistent with the fact that non-small-cell lung carcinoma, when it arises peripherally, most commonly presents without pulmonary symptoms.…”

Ultrasound of muscle

“…Intramuscular metastases are extremely rare. The most common primary tumours are lung [24,25], breast [26], gastrointestinal tract [27,28] and kidney [29,30]. Skeletal muscle deposits from gynaecological malignancies [27], malignant melanoma [31], leukaemia and lymphoma [32] have also been observed.…”

CT of Unusual Iliopsoas Compartment Lesions

“…These findings are nonspecific and are indistinguishable from those of metastases and lymphoma (14). Although gas bubbles, which are suggestive of infection (2,5,8,9,12), are rarely seen in tumor and hemorrhage, they have been described in both these conditions (9,15,16). In their series, Lenchik et al (15) report that a low-attenuation lesion was the most reliable CT feature of iliopsoas abscess.…”