Extraocular sebaceous carcinoma of the chest wall: A case report.

INTRODUCTION

Sebaceous carcinoma is a rare malignancy that is most commonly found in the head and neck region, particularly in the periocular region. Extraocular lesions are rarer, however are thought to have a higher association with Muir-Torre Syndrome, a variant of Lynch Syndrome, that affects both sebaceous glands and visceral organs.

CASE PRESENTATION: Our patient was a 54 year old male with a past medical history of hypertension, stroke, and vertigo who presented to the emergency department with paresthesias concerning for a transient ischemic attack in the setting of a hypertensive emergency. After admission, the patient reported an abscess on the chest that was present for four months prior. Subsequent physical exam incidentally revealed a fungating mass located on the chest wall. The mass was noted to have central ulceration and necrosis.

CLINICAL DISCUSSION: CT scan of the chest with intravenous contrast revealed that the mass did not invade the chest wall, therefore a surgical excision was performed. A final diagnosis of sebaceous carcinoma was made after microscopic examination of the resected mass. Immunohistochemistry revealed loss of expression of mismatch repair genes. The patient was lost to follow-up before any additional work up could be performed.

CONCLUSION

Extraocular sebaceous carcinomas should be tested using immunohistochemistry for loss of expression of mismatch repair genes. Patients with loss of expression should be risk stratified using the Mayo Muir-Torre risk score to determine if they should undergo germline genetic testing for Lynch Syndrome. Patients with issues in adherence represent a unique diagnostic challenge in potentially evolving diseases.