Lentigo maligna.

Lentigo maligna (LM), a melanoma in situ, is a fairly common melanocytic lesion that usually develops on the chronically sun-exposed skin of the head and neck of Caucasians. It occurs mostly in people older than 40 years, with an incidence rate that increases with age and peaks in the seventh and eighth decades of life. Its diagnosis and treatment remain challenging. In this article, we review the history, epidemiology, clinical presentation, histology, and treatment of LM.

Kaposiform hemangioendothelioma with Kasabach-Merritt syndrome mistaken for child abuse in a newborn.

Kaposiform hemangioendothelioma is a rare vascular neoplasm of childhood that may have an alarming and potentially misleading clinical presentation. Awareness of this entity is important to provide appropriate and immediate medical care. We report the case of a 24-day-old female newborn who presented with a large bruiselike lesion on the left leg. A diagnosis of cellulitis suspected to be secondary to child abuse was made and the patient subsequently was placed in foster care; however, the lesion did not resolve after treatment and relocation. On reevaluation at our institution, physical examination revealed a round, 3 x 4-cm, violaceous, indurated, fixed, nonblanching, nontender plaque with an ivory center and peripheral erythema over the anteromedial aspect of the left leg. Biopsy demonstrated a vascular neoplasm consistent with kaposiform hemangioendothelioma (KHE), and laboratory evaluation revealed thrombocytopenia, low fibrinogen levels, and elevated D-dimer levels, confirming a diagnosis of Kasabach-Merritt syndrome (KMS).

Chondroid tenosynovial giant cell tumor: a clinicopathological and immunohistochemical analysis of 5 new cases.

Tenosynovial giant cell tumor (TGCT) arises from the synovium of joints or tendon sheaths. Chondroid metaplasia in TGCT is rare with only 4 well-documented cases reported in the literature. The authors describe the morphological features and immunophenotype of 5 new cases of chondroid TGCT emphasizing a broader range of matrix patterns in these tumors and an expanded immunophenotype, specifically, staining for clusterin and podoplanin which have recently been found to be expressed in conventional TGCTs. Chondroid metaplasia was extensive in 3 cases. Matrix patterns included chondromyxoid, chondro-osseous, hyaline-like, and lace-like calcification similar to that seen in chondroblastoma. The authors conclude that chondroid TGCT is a rare, distinct synovial tumor with a predilection for the temporomandibular joint that has a similar immunophenotype as conventional TGCT. Chondroid metaplasia may be extensive and have a variety of matrix patterns. Chondroid TGCT needs to be distinguished from other chondroid lesions, including chondroblastoma and chondrosarcoma.