Renal cell carcinoma presenting with malignant ascites

Lost in third space: altered tyrosine-kinase inhibitor pharmacokinetics in a patient with malignant ascites

BACKGROUND

Pazopanib and sunitinib are oral tyrosine kinase inhibitors (TKI) approved for the treatment of renal cell carcinoma. For both oncolytics, a clear target trough concentration level in plasma has been defined above which improved clinical efficacy can be expected. However, many factors can alter TKI exposure, including disease characteristics.

CASE

A 79-year old male with metastatic papillary renal cell carcinoma and malignant ascites was treated with pazopanib. Initially, treatment with pazopanib at adequate trough concentrations resulted in regression of ascites. After a 6-month puncture-free interval, paracenteses were again required and the plasma trough concentration of pazopanib had decreased to 5 mg/L without any dose adjustments. Despite a dose increase, pazopanib levels remained subtherapeutic and could not prevent new paracenteses. Pazopanib concentrations in the drained ascites fluid were comparable to plasma concentrations and remained high also after treatment discontinuation. This observation suggests that the ascites compartment may act as a third space in which pazopanib accumulates. During subsequent treatment with sunitinib, a similar distribution over ascites fluid was observed.

CONCLUSION

Presence of ascites or pleural effusion in patients treated with TKIs may lead to subtherapeutic plasma exposure, which may hamper treatment efficacy. Measuring TKIs plasma concentrations regularly during treatment is essential to identify patients with subtherapeutic exposure.

Malignant ascites following radical nephrectomy for cystic renal cell carcinoma

A 69-year-old man with a history of laparoscopic radical nephrectomy for papillary renal cell carcinoma presented with a 1-week history of generalised abdominal pain, distension and loss of appetite. Clinical examination and CT imaging demonstrated ascites associated with peritoneal nodules, raising the possibility of metastatic disease. Immunochemistry staining from ascites fluid cytology confirmed renal cell carcinoma. Following multidisciplinary discussions, the patient was commenced on a small-molecule tyrosine kinase inhibitor.

Renal Cell Carcinoma Mimicking with Peritoneal Carcinomatosis and Krukenberg Tumor: Diagnosis Seen on Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Krukenberg tumor (KT) is a rare clinical entity with a mysterious origin. It originates most commonly from adenocarcinoma of the stomach. We present an interestingly rare case of this entity in renal cell carcinoma, revealed by ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) scan. Ovarian cancers with diffuse peritoneal metastasis were considered the differential diagnosis of the disease, based on PET/CT. The potential efficacy of this functional imaging for KT is still in the exploratory phase, but its applications in diagnosis, disease prognostication, therapeutic response monitoring, and follow-up recurrence detection are superior than other imaging modalities.