Complete response to pembrolizumab in a patient with recurrent and metastatic urothelial bladder carcinoma reflecting coexisting sarcomatoid subtype and glandular differentiation: a case report

A pathological complete response and adrenal insufficiency in a patient with advanced renal pelvic cancer treated with pembrolizumab

Metastatic upper tract urothelial carcinoma (mUTUC) often has poor prognosis. While systemic therapy is the standard care for mUTUC, lymph node dissection (LND) combined with radical nephroureterectomy (RNU) can be considered for patients with only clinical locoregional LN, resulting in a surgical cure. However, since pembrolizumab, an anti-PD-1 monoclonal antibody, was approved for mUTUC patients, prognosis of mUTUC has been improved and some patients with immune-related adverse events have experienced a clinical complete response and a long-lasting therapeutic response without surgery. Thus, clarifying the optimal patient selection and timing for RNU + LND is warranted to avoid unnecessary surgery. We herein report the first unique case with a clinical N + UTUC patient who underwent RNU plus LND and showed a pathological complete response after discontinuation of pembrolizumab due to adrenal insufficiency. We feel that our case may affect the treatment strategy for N + UTUC in the era of ICIs.

Mucin-producing urothelial-type adenocarcinoma of the prostate with sarcomatoid features and novel molecular phenotype

Introduction

Mucin-producing urothelial-type adenocarcinoma of the prostate is a rare tumor that may not elevate serum prostate-specific antigen, creating significant diagnostic and monitoring challenges. We evaluate our case in detail and review prior studies to demonstrate that the pathologic and molecular features of this tumor are distinct from conventional prostate adenocarcinoma.

Case presentation

Our patient had a remote history of radiation-treated conventional prostate adenocarcinoma and presented many years later with an abscess-like prostate mass leading to urinary obstruction and hematuria. Biopsy revealed mucin-producing urothelial-type adenocarcinoma of the prostate with concurrent sarcomatoid features. Molecular studies showed a unique phenotype involving alterations in the KRAS, PTEN, RAD21, and TP53 genes.

Conclusions

To our knowledge, this is the first report that describes sarcomatoid features and molecular mutations in mucin-producing urothelial-type adenocarcinoma of the prostate.