A 25-yr-old man with a C5 American Spinal Injury Association grade A spinal cord injury secondary to a diving accident 2 yrs previously presented for evaluation of a right scapular mass that had been increasing in size for the previous 9 mos. He reported vague pain of his right shoulder initially, but he did not seek medical attention until he noticed the mass. He complained of pain on deep palpation and shooting pain from the left shoulder to the right arm. He had no other associated symptoms.
On physical examination, the patient was noted to have a 10 × 10 cm mass, which was nonfluctuant, firm, and nonmovable (Fig. 1). He had tenderness to deep palpation. Passive range of motion of the right glenohumeral joint was 0–90 degrees of abduction, 0–90 degrees of flexion, 0–45 degrees of extension, and 0–30 degrees of internal and external rotation.
Chest radiographs revealed a prominent soft-tissue density along the lateral aspect of the right side of the chest. A computed tomographic scan with intravenous contrast of his thorax revealed a right posterior chest wall mass measuring 10 cm in transverse diameter involving the transverse spinal, iliocostalis, longissimus thoracis, and the right rhomboid muscles, with no obvious bony destruction (Fig. 2).
A computed tomographically guided fine-needle aspiration biopsy revealed a spindled soft-tissue proliferation most consistent with extraabdominal fibromatosis, or desmoid tumor. The patient subsequently underwent surgical excision of the tumor, and pathologic analysis confirmed the presence of spindle cells with abundant rough endoplasmic reticulum in the cytoplasm and features consistent with myofibroblastic differentiation and desmoid tumor.
Extraabdominal fibromatosis, or desmoid tumor, is a benign fibrous proliferative tumor that characteristically grows into local surrounding structures. This tumor arises from the aponeurotic fascia of muscles and is found most commonly in adolescents and young adults. It has been reported to be associated with Gardner's syndrome.1–3
The tumor most commonly involves the shoulder and pelvic girdles and usually presents as a deep, firm, solitary mass. Pain is usually produced with palpation or with movement of the affected musculature or may be spontaneous with involvement of a contiguous nerve.
This visual vignette describes an extraabdominal fibromatosis in a patient with C5 American Spinal Injury Association grade A tetraplegia. Early detection might be challenging due to the patient's baseline impairment in active motion. In the non–spinal-cord-injury population, impairment in active range of motion at the glenohumeral joint may precede the development of a perceptible mass, leading to early diagnosis and treatment. Although uncommon, it is therefore important to suspect a possible soft-tissue mass in a spinal-cord-injury patient presenting with vague shoulder pain and loss in passive range of motion.
1. Johnston JO, Helms CA, Weidner N: Soft-tissue shoulder mass in a 55-year-old man. Clin Orthop Relat Res 1996;324:340–2
2. Sikka RS, Vora M, Edwards TB, et al: Desmoid tumor of the subscapularis presenting as isolated loss of external rotation of the shoulder: A report of two cases. J Bone Joint Surg (Am) 2004;86:159–64
3. Simpson JL, Petropolis AA, Styles AR, et al: Extra-abdominal desmoid tumor: An unusual subcutaneous lesion presenting as shoulder pain. Int J Dermatol 1998;37:780–4