Giant cell tumor of the bone: aggressive case initially treated with denosumab and intralesional surgery.

Giant cell tumor of the bone (GCTB) is a locally aggressive benign tumor, which has historically been treated with wide surgical excision. We report a case of a 29-year-old male with histology-proven GCTB of the distal ulna. The initial imaging study was a contrast-enhanced magnetic resonance imaging (MRI) examination of the left wrist, which was from an outside facility performed before presenting to our institution. On the initial MRI, the lesion had homogenous T2-hyperintense and T1-hypointense signal with expansive remodeling of the osseous contour. A radiographic study performed upon presentation to our institution 1 month later showed progression of the lesion with atypical imaging characteristics. After confirming the diagnosis, denosumab therapy was implemented allowing for reconstitution of bone and intralesional treatment. The patient was treated with five doses of denosumab over the duration of 7 weeks. Therapeutic changes of the GCTB were evaluated by radiography and a post-treatment MRI. This MRI was interpreted as suspicious for worsening disease due to the imaging appearance of intralesional signal heterogeneity, increased perilesional fluid-like signal, and circumferential cortical irregularity. However, on subsequent intralesional curettage and bone autografting 6 weeks later, no giant cells were seen on the specimen. Thus, the appearance on the MRI, rather than representing a manifestation of lesion aggressiveness or a non-responding tumor, conversely represented the imaging appearance of a positive response to denosumab therapy. On follow-up evaluation, 5 months after intralesional treatment, the patient had recurrent disease and is now scheduled for wide-excision with joint prosthesis.

Molecular characterization of visible low-grade dysplastic lesions in patients with inflammatory bowel disease.

We studied pathogenic gene mutations and tumor mutation burden (TMB) in visible low-grade dysplastic lesions in patients with inflammatory bowel disease (IBD). The dysplastic lesions with histologically normal mucosa in the background (group 1) were compared with dysplastic lesions occurring either in a background of chronic active colitis (group 2) or associated with synchronous carcinomas regardless of the status of the background mucosa (group 3). The TMB in group 3 was consistently higher in comparison to the group 1 and group 2 lesions, although the difference was not statistically significant. There also seem to be different mutation profiles between the groups, indicating different pathways of tumor pathogenesis. More frequent APC mutations were seen in group 1 as compared to other groups and TP53 mutations were seen in groups 2 and 3, but none in group 1. Molecular characterization could potentially be used as an ancillary prognostic marker in challenging cases to guide the further management of IBD patients with visible dysplastic lesions.

A Rare Case of Ovarian Serous Borderline Tumor with Brain Metastasis.

Background. Serous borderline tumor represents a group of noninvasive tumor of the ovary bridging between benign serous cystadenoma and serous carcinoma. They are commonly seen in younger women and usually have an excellent outcome but seldom show local recurrence (J. F. Leake et al. 1991). Metastasis to the lymph nodes has rarely been reported (M. D. Chamberlin et al., 2001; M. B. Verbruggen et al., 2006). Moreover, the brain is exceptionally a rare metastatic site for ovarian tumor. There is one case of an advanced staged SBT with micropapillary pattern metastasis to the brain recently and by far it is the most distant metastasis reported (M. D. Martin et al., 2017). However, to the best of our knowledge, no report has been documented for a recurrent stage 1 typical SBT metastasizing to the brain.