Osteoma cutis, a propósito de un caso

Osteoma cutis (OC) is a lesion composed of bone tissue lo- cated in the dermis and/or hypodermis. It is classi ed as primary when it develops over healthy skin; and secondary when it develops over preexisting lesions. A 61-year-old wo- man with history of Hodgkin lymphoma in remission, pre - sents a longstanding lesion located on the rst nger of her left hand which developed over healthy skin, associated with recurrent and self-limited episodes of pain and increased lo- cal temperature. Physical examination reveals a stone-hard nodule, with a calcareous-bottomed ulcer. The histopatholo - gical evaluation of the excisional biopsy revealed bone tissue. Complementary studies included: complete blood count, re - nal and hepatic function, plasma calcium and phosphorus, PTH, TSH, vitamin D, and urinary calcium, all of them in normal ranges. Once systemic disease was ruled out, plate- like OC was diagnosed. OC is a benign lesion which can be primary or secondary. Secondary OC represent nearly 85% of cases, and it corresponds to an ossi cation of preexisting tumoral or in ammatory lesions. Primary OC is less frequent, it appears isolated or as part of syndromes like brodyspla - sia ossi cans progressiva, Albright hereditary osteodystrophy, and progressive osseous heteroplasia. GNAS mutations have been described in primary OC as in these syndromes, but the nal diagnosis relies on the clinical picture. Isolated primary OC is classi ed in milliary osteomas of the face and plate-like OC, like our case. When facing primary OC, syndromes that present with heterotopic ossi cation must be ruled out.