Carcinoma Cuniculatum of the Foot Invading the Bone Mimicking a Pseudo-Epitheliomatous Reaction to an Acute Osteomyelitis

Clinical characteristics, treatment, and prognosis of squamous cell carcinoma arising from extremity chronic osteomyelitis: a synthesis analysis of one hundred and seventy six reported cases

PURPOSE

Squamous cell carcinoma (SCC) arising from extremity chronic osteomyelitis (COM) has not been well-understood due to its low prevalence. This study aimed to synthesize the cases recently published to clarify their clinical characteristics, treatment, and prognosis.

METHODS

PubMed, Embase, and Cochrane Library databases were searched for English literature reporting cases diagnosed of SCC originating from extremity COM between January 1, 1990, and September 30, 2019. The National Institutes of Health (NIH) assessment tool was used to evaluate the quality of reports included, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was applied to summarize the quality of available evidence. The data synthesized for analysis were clinical features, treatment strategy, and incidences of local recurrence, metastasis, all-cause, and SCC-related deaths. In addition, potential factors that might have influenced treatment efficacy and prognosis of SCC were also investigated.

RESULTS

Included for this analysis were 60 studies of 176 patients (a male-to-female ratio of 6.7). COM mostly occurred following trauma (73%), the tibia was the most frequent site (61%), and a sinus tract was the most common symptom (61%). The mean duration from COM to SCC was 27 years. Positive rate of pathogen culture was 90%, with 73% being polymicrobial. Limb amputation was performed in 80.5% of the patients. Incidences of local recurrence, metastasis after treatment, all-cause, and SCC-related mortalities were 16.7%, 12%, 31.1%, and 12.6%, respectively. Patients with local lymphadenopathy at diagnosis had significantly higher risks of local recurrence (P = 0.01), SCC-related (P = 0.02), and all-cause deaths (P = 0.01) than those without. Patients with moderately-to-poorly differentiated SCC types had significantly higher risks of local recurrence (P = 0.01) and all-cause death (P = 0.02) than those with a well-differentiated type.

CONCLUSIONS

SCC arising from extremity COM favoured males and the tibia. Although limb amputation was the mainstay of treatment, the overall incidences of local recurrence, metastasis, and SCC-related death exceeded 10%. Patients with local lymphadenopathy at diagnosis of SCC and those with moderately-to-poorly differentiated SCC types should be followed up closely.

TRIAL REGISTRATION

CRD42020154221.

Carcinoma Cuniculatum of the Lower Leg: A Case Report and Proposed Diagnostic Criteria

Carcinoma cuniculatum is an infrequent variant of squamous cell carcinoma described for the first time by Ian Aird in 1954. Since then, multiple reports of cutaneous carcinoma cuniculatum have been published at various sites, including palms, soles, buttocks, and lower legs, but most of them did not match to original description. In the current study, we report a unique case of a 69-year-old woman with carcinoma cuniculatum arising in the calf. Moreover, we update the histopathological criteria of cutaneous carcinoma cuniculatum by combining the literature descriptions and the experiences from the current case.

Carcinoma Cuniculatum of the Alveolar Mucosa: A Rare Variant of Squamous Cell Carcinoma

Carcinoma cuniculatum is one of the variants of squamous cell carcinoma. It is significantly rare with an incidence rate < 1% compared to other histological variants of squamous cell carcinoma. Various etiologic factors implicated are trauma, HPV, chronic inflammation and alcohol consumption but real causative agent still remains unclear. Initially it resembles plantar wart which slowly progress to bulky exophytic mass in the sole of the foot, where cases have been reported first. In the oral cavity it presents clinically as an exophytic growth and slowly invades the jaw and destroys the underlying bone. Microscopically it exhibits as both exophytic and endophytic epithelial masses along with well differentiated and pronounced hyperkeratosis. Treatment includes surgical resection alone unlike other variants which are treated by radiation with or without chemotherapy. Here we present a case of carcinoma cuniculatum occurred in alveolar mucosa of a 47 years old female. It presented as an exophytic growth in mandibular alveolar region, with histological features consistent with carcinoma cuniculatum.