Primary nonkeratinizing squamous cell carcinoma of the scapular bone: A case report

Abstract

Background: Squamous cell carcinoma (SCC) of bone is usually caused by metastasis from the lungs, bladder, or other sites. Primary SCC of bone most frequently involves the skull bones, and primary involvement of other sites in the skeletal system is extremely rare. To date, only three such cases have been reported, which makes the diagnosis, treatment, and prognosis of this disease a challenge.

Case summary: A 76-year-old Chinese man presented to our hospital with nonspecific pain and limited mobility in the right shoulder for 4 mo. He underwent three-dimensional computed tomography reconstruction and magnetic resonance imaging of the right shoulder, which revealed an osteolytic destructive lesion in the right scapula with invasion into the surrounding muscles and soft tissues. Ultrasound-guided core needle biopsy detected a malignant tumor, and immunohistochemical analysis revealed a poorly differentiated SCC. Wide excision of the right scapular bone was performed, and pathological examination of the surgical specimen confirmed the diagnosis. At the last follow-up examination within 2 years, the patient was doing well with the pain significantly relieved in the right shoulder.

Conclusion: Primary SCC of bone is extremely rare at sites other than the skull. Clinicians must exhaust all available means for the diagnosis of primary SCC of the bone, so greater attention can be paid to its timely and effective management. Regular and adequate follow-up is essential to help rule out metastasis and judge the prognosis.

Keywords: Case report; Diagnosis; Immunohistochemistry; Keratin pearls; Primary squamous cell carcinoma; Scapular bone.

Figure 1

Three-dimensional computed tomography reconstruction. A and B: Osteolytic destructive lesion in the right scapular bone.

Figure 2

Magnetic resonance imaging A (t2-tse) and B (pd-tse-fs) show an osteolytic destructive lesion in the right scapular bone, invading the surrounding muscles and soft tissues.

Figure 3

Histological findings. A: Histopathological examination of the biopsy specimen shows malignant tumor cells in the trabecular bone space but no typical keratin pearls (hematoxylin and eosin stain; original magnification, 100 ×); B-D: Immunohistochemical labeling reveals that the tumor cells are reactive to cytokeratin 5/6, p63, and p40 (original magnification, 40 ×).

Figure 4

Primary nonkeratinizing squamous cell carcinoma of the right scapular bone. A: Surgically resected specimen shows a dark red ovoid mass originating from the right scapula that appears creamy-white and soft on cross section; B: The right humeral head, right collarbone, and surrounding muscle were used to reconstruct the resulting defect.