Positive Response to Fluorouracil and Oxaliplatin in Signet Ring Cell Adenocarcinoma of the Bladder Presenting With Retroperitoneal Fibrosis.

Bladder adenocarcinoma is an uncommon type of bladder cancer. Signet ring cell pathology is a rare subtype of bladder adenocarcinoma. Global incidence rates of signet ring cell adenocarcinoma of the bladder have not been established. Management of signet cell bladder cancer is challenging as it is aggressive in behavior with frequent relapse despite chemotherapy. Here we present a case of stage IV signet cell bladder cancer with retroperitoneal fibrosis treated with FOLFOX (folinic acid, 5-fluorouracil, oxaliplatin) regimen with a complete durable response.

Efficacy of Venetoclax and Dexamethasone in Refractory IgM Primary Plasma Cell Leukemia with t(11;14) and TP53 Mutation: A Case Report and Literature Review.

Primary plasma cell leukemia (pPCL) is an uncommon disease. IgM multiple myeloma (MM) is an infrequent subtype that accounts for less than 1 percent of MM cases. IgM pPCL is quite rare with only a few cases published to date. We describe a case of a patient with IgM pPCL who initially presented with hyperviscosity syndrome requiring urgent plasma exchange. His bone marrow biopsy demonstrated t(11;14). He progressed on proteasome inhibitors, immunomodulating agents, and other chemotherapy medications but later achieved very good partial response (VGPR) to venetoclax and dexamethasone. Given the poor prognosis of pPCL, further studies using venetoclax alone or in combination with other novel agents as first-line treatment options are warranted particularly in patients with t(11;14).

A rare case of choroid plexus carcinoma that led to the diagnosis of Lynch syndrome (hereditary nonpolyposis colorectal cancer).

Lynch syndrome (hereditary nonpolyposis colorectal cancer) is an autosomal dominant disorder characterized by a significant risk of colorectal and endometrial cancers. A variety of other epithelial cancers may be associated with this syndrome. Brian tumors are infrequent, but have been reported in series. Here, we report a case of a 34-year-old Caucasian woman with WHO grade III choroid plexus carcinoma (CPC). Comprehensive genomic profiling of the patient's resected brain tumor revealed mutations in six genes: PTEN, VHL, MSH6, NOTCH1, RB1, and TP53. Family history is significant for endometrial cancer in her mother and sister as well as colon cancer in her maternal grandfather suggestive of Lynch syndrome. Site-specific mutational analysis showed the MSH6 mutation (p.R482*) in peripheral lymphocytes. Subsequently we performed immunohistochemical staining of the tumor tissue which demonstrated widespread loss of MSH6 with intact MSH2, MLH1, and PMS2. The diagnosis of Lynch syndrome due to a mutation in MSH6 was therefore established. Our patient elected to have adjuvant radiation to the surgical bed only followed by prophylactic total abdominal hysterectomy and bilateral salpingo-oophorectomy and is doing very well. To our knowledge, this is the first case report of CPC in an adult patient with a germline MSH6 mutation. We believe our data have provided molecular evidence to suggest that CPC could potentially be part of the Lynch syndrome spectrum.