Sciatica is a highly prevalent condition. Its main presenting symptoms are radiating pain in the lower extremity with possible sensory or motor disturbances. In about 90% of cases sciatica is caused by disc herniation with nerve root compression.^[1] Lumbar stenosis and tumors are other less common etiologies.^[1] Few cases in the literature report sciatic pain due to gluteal masses.^[2,3] We describe a patient with left sciatic pain of 3 years duration who failed to respond to conservative medical treatment. Magnetic resonance imaging showed a large oval mass interposed between the gluteus medius and gluteus maximus muscles and insinuating within the fibers of the gluteus medius. The patient’s pain completely resolved after surgical excision of the mass. This represents an uncommon, yet a possibly treatable and reversible etiology of sciatica and should be considered in the differential diagnosis of this condition

Keywords: Sciatica, intramuscular lipoma,back pain,soft tissue mass,gluteal lipoma.

1. Koes, B.W., M. Van Tulder, and W. Peul, Diagnosis and treatment of sciatica. Bmj, 2007. 334(7607): p. 1313-1317.
2. de Almeida Holanda, M.M., et al., Intermuscular gluteal lipoma mimicking sciatic pain. Chil. Neurocirugía, 2014. 40: p. 117-118.
3. Lirola, S., et al., A Buttock Soft Tissue Tumor and Sciatica: Another Clinical Utility of Ultrasound-Guided Diagnosis Block. Journal of Anesthesia & Clinical Research, 2013, vol. 4, num. 3, p. 1-4, 2019.
4. McTighe, S. and I. Chernev, Intramuscular lipoma: a review of the literature. Orthopedic reviews, 2014. 6(4).
5. Murphey, M.D., et al., From the archives of the AFIP: benign musculoskeletal lipomatous lesions. Radiographics, 2004. 24(5): p. 1433-1466.
6. Regan, J., W. Bickel, and A. Broders. Infiltrating benign lipomas of the extremities; report of two cases. in Proceedings of the staff meetings. Mayo Clinic. 1946.
7. Fletcher, C. and E. Martin‐Bates, Intramuscular and intermuscular lipoma: neglected diagnoses. Histopathology, 1988. 12(3): p. 275-287.
8. Ramos, L.P., et al., Intramuscular lipoma of the deltoid mimicking a sarcoma. A case report. La Chirurgia degli organi di movimento, 2001. 86(2): p. 153-157.
9. Warner, J., N. Madsen, and C. Gerber, Intramuscular lipoma of the deltoid causing shoulder pain. Report of two cases. Clinical orthopaedics and related research, 1990(253): p. 110-112.
10. Morris, A.D., et al., Diffuse intramuscular lipomatosis of a lower limb. Sarcoma, 1998. 2(1): p. 53-56.
11. Gutknecht, D.R., Painful intramuscular lipoma of the thigh. Southern medical journal, 2004. 97(11): p. 1121-1123.
12. Kapetanakis, S., et al., Unusual intramuscular lipoma of deltoid muscle. Folia Medica, 2010. 52(2): p. 68-71.
13. Lee, Y.H., et al., Intramuscular lipoma in thenar or hypothenar muscles. Hand Surgery, 2004. 9(01): p. 49-54.
14. Kindblom, L.G., et al., Intermuscular and intramuscular lipomas and hibernomas. A clinical, roentgenologic, histologic, and prognostic study of 46 cases. Cancer, 1974. 33(3): p. 754-762.
15. Colella, G., et al., Giant intramuscular lipoma of the tongue: a case report and literature review. Cases journal, 2009. 2(1): p. 1-3.
16. Dutton, J.J. and J.D. Wright Jr, Intramuscular lipoma of the superior oblique muscle. Orbit, 2006. 25(3): p. 227-233.
17. Kransdorf, M., et al., Fat-containing soft-tissue masses of the extremities. Radiographics, 1991. 11(1): p. 81-106.
18. Lahrach, K., et al., An unusual case of an intramuscular lipoma of the biceps brachii. Pan African Medical Journal, 2013. 15(1).

Fadila Naji

Department of Family Medicine, American University of Beirut Medical Center, Beirut, Lebanon