Atypical fibroxanthomas are rare, superficial dermal tumors. Most cases are benign and only locally destructive with a low rate of metastasis. Lesions are most commonly found on sun-exposed sites of elderly light-skinned patients and present as asymptomatic nodules with irregular borders; ulcerations and friability are other key characteristics. Pedunculated lesions, however, are rarely described in the literature. We present two cases of atypical fibroxanthoma manifesting as exophytic, pedunculated lesions on the face: one in a 74-year-old man and the other in an 82-year-old woman. These tumors are very effectively treated by excision with Mohs micrographic surgery.

Keratoacanthoma centrifugum marginatum (KCM) is an uncommon variant of keratoacanthoma. Keratoacanthoma centrifugum marginatums are most commonly seen on sun-exposed surfaces and present with progressive peripheral expansion and raised, hyperkeratotic borders. Central clearing with atrophy and lack of spontaneous clearance are other key clinical characteristics. The majority of cases are benign with a low risk of metastasis. The size of such growths is variable with reported cases ranging from 5.0cm×5.0cm to as large as 20.0cm×14.0cm. Treatment options include surgical excision, oral retinoids, and intralesional chemotherapeutics such as methotrexate or bleomycin. We herein present a case of KCM manifesting as an exophytic, crateriform plaque in a 61-year-old man.

A 26-year-old man with a history of congenital bilateral microtia, unilateral renal agenesis, left aural atresia, and right external auditory canal occlusion admitted for right rib cartilage graft harvest and left ear re-construction. Following surgery, an ulceration with violaceous borders and a yellow fibrinous base unresponsive to broad-spectrum antibiotics developed at the harvest site. The wound was expanding and not responsive to systemic broad-spectrum antibiotics. Biopsy revealed a dense dermal infiltrate of neutrophils with negative tissue cultures consistent with pyoderma gangrenosum (PG). He was treated with systemic, intralesional, and topical steroids, as well as doxycycline. Three weeks after the diagnosis of PG, he was found to have persistent anemia and leukopenia. Bone marrow aspiration analysis was consistent with hypocellular myelodysplastic syndrome and genetic testing was consistent with Fanconi anemia. There is a well-known association of PG with hematological disorders. Fanconi anemia is a rare genetic hematologic disorder with congenital defects leading to bone marrow failure and malignancy in long-standing disease. In our patient, we consider his development of PG a paraneoplastic sign associated with the onset of his hypocellular myelodysplastic syndrome.