Trichoblastic Carcinosarcoma of the Skin: A Case Report and Literature Review.

An 83-year-old man presented to the dermatology department for an ulcerated skin lesion of the back that had been increasing in size during the past 11 years. The physical examination revealed a well-defined, fleshy, reddish plaque measuring 10 × 20 cm in diameter with erosions and black areas on the surface. The patient underwent surgical excision with margins of 10 mm followed by a skin graft. Histologic section showed a lesion composed of 2 intimately intermingled epithelial and mesenchymal components associated with a basal cell carcinoma (BCC). Immunohistochemical examination showed epithelial cells that were positive for CK AE1/AE3 and p53, whereas stromal cells were positive for vimentin, CD10, and p53. BCC was positive for CD10. On the basis of these findings, a diagnosis of trichoblastic carcinosarcoma associated with BCC was made. Given the scarcity of data available in the literature regarding this diagnosis, no standard of care exists. No adjuvant treatment was provided and after 1 year of follow-up, the patient did not experience recurrence.

Glioblastoma Secondary to Meningioma: A Case Report and Literature Review.

BACKGROUND: The pathophysiologies underlying meningioma and glioma are distinct. The coexistence of those 2 lesions in the same patient is rare, and at the same location, it is even more exceptional. CASE DESCRIPTION: We report a case of a 79-year-old man initially presenting with a meningioma that was treated by complete excision of the lesion. The patient had 2 relapses at the same site, in which glioblastoma was confirmed histopathologically. CONCLUSIONS: Glial transformation meningiomas remain a contentious issue, with coincidental occurrence being the most prevalent explanation. Nevertheless, impairment of the same molecular signaling pathways in both tumor types suggests a common origin. Another hypothesis is that perilesional parenchymal damage from radiotherapy or surgery may lead to glial transformation in the tissues surrounding the original meningioma lesion. Further research is needed to determine if the original tumor or surgery has an oncogenic effect on the adjacent tissue.

Characterization of S628N: a novel KIT mutation found in a metastatic melanoma.

IMPORTANCE The KIT receptor is mutated in approximately 15%of acral, mucosal, and chronic, sun-damaged melanomas. The status of KIT mutations is of interest because they usually are mutually exclusive with N-RAS and B-RAF mutations and because of the availability of KIT kinase inhibitors in the clinic. Some recurrent KIT mutations are well characterized; others are poorly described.OBSERVATIONS We describe a novel KIT mutation in a patient with metastatic melanoma. The mutation, located in exon 13, resulted in S628N substitution in the KIT receptor. Using all-atom molecular dynamics simulations, biochemical assays, and cell-based assays, we showed that the mutation is a bona fide gain-of-function oncogenic mutation. Furthermore,we evaluated the sensitivity of the mutant to imatinib and dasatinib.CONCLUSIONS AND RELEVANCE We report a novel KIT gain-of-function mutation with S628N substitution (exon 13) and show that it is sensitive to imatinib in vitro. Therefore, patients with this mutation may be eligible for KIT kinase inhibitor­based therapy. Further studies are needed to evaluate the clinical benefit of such therapy.

Osteochondrolipoma of the submandibular region: a case report and review of the literature.

Lipoma is an extremely common and ubiquitous benign soft tissue tumor composed of mature adipose tissue, with frequent differentiation towards other mesenchymal elements such as blood vessels, fibrous tissue, or muscle. They are typically slow-growing, encapsulated, superficial or deep, and have a wide range in size depending on their location. The presence of cartilage or bone is very rare, with most reported cases in the head and neck area. We report the case of an osteochondrolipoma of the submandibular region with associated benign bone marrow elements, with a review of the literature and discussion of the differential diagnosis.