Squamous cell carcinoma (SCC) is a rare but often devastating complication of chronic osteomyelitis. Optimum diagnosis and management are not well established. This paper aimed to develop a definitive, evidence-based approach to its diagnosis and management.
A systematic review of relevant published studies available in English from 1999-present was conducted. Strict inclusion criteria ensured that the diagnoses of osteomyelitis and SCC were explicit and valid. Additional cases from our institution were included using the same eligibility criteria. Data regarding patient demographics, osteomyelitis diagnosis, SCC diagnosis and its management and patient outcomes were collected. Statistical significance was assessed by Fisher's exact test.
Nineteen publications involving 98 patients plus eight patients managed locally were included. Eighty percent of patients were male, diagnosed with SCC at an average age of 59 years old (24–82 years), 31 years after their osteomyelitis diagnosis (3–67 years). Multiple bones were affected: tibia or fibula (59%), femur (17%), pelvis and sacrum (8%), bones of the foot and ankle (8%) and upper limbs (6%). Malignant transformation was associated predominantly with sinus (82%), ulceration (61%) and discharge (41%). SCC was diagnosed by biopsy (77%) or incidentally (23%) following definitive management for osteomyelitis. Twenty-two percent of patients had a staging CT scan. Seventy-six percent of patients underwent amputation, 16% underwent limb-sparing wide local excision and the remaining patients were palliated.
Incidental diagnosis of SCC was associated with poorer outcomes in terms of death or disease recurrence (one year, p=0.052, five years p=0.021, Fisher's exact test) as was metastatic disease at SCC diagnosis (one year, p=0.006, five years, p=0.032, Fisher's exact test) and pelvic or sacral disease (one year p<0.001, five years p=0.002, Fisher's exact test).
All patients who were not actively treated died within one year of SCC diagnosis. Data was suggestive that more patients who underwent amputation (versus wide local excision) were disease free at one and five years, but this was not statistically significant (one year, p=0.058, five years, p= 0.152, Fisher's exact test).
SCC should be suspected in all cases of chronic osteomyelitis with skin changes, particularly where changes exceed 3 years duration and involve the pelvis. Multiple biopsies for histology should be taken in all suspected cases, as well as routinely during surgical excision of osteomyelitis when chronic skin changes are present. Once SCC is identified, staging CT scan should be performed to guide management. Amputation, where possible, should be considered.