Is a 3mm nodule, visible on CT imaging 3 years after partial nephrectomy for stage 1 Chromophobe Renal Cell Carcinoma (RCC), located in the fat anterior to the psoas muscle below the lower pole of the left kidney, likely benign?

From the Guidelines

A 3mm nodule, visible on CT imaging 3 years after partial nephrectomy for stage 1 Chromophobe Renal Cell Carcinoma (RCC), located in the fat anterior to the psoas muscle below the lower pole of the left kidney, is most likely benign due to its small size, stable nature over time, and the favorable prognosis of chromophobe RCC. The patient's history of stage 1 chromophobe RCC, which was treated with partial nephrectomy, suggests a low risk of recurrence or metastasis, as supported by studies such as 1. The small size of the nodule (3mm) and its location in the fat anterior to the psoas muscle are also reassuring features. Malignant lesions typically grow over time, but this nodule has shown no change in size for 3 years, which further supports its benign nature.

Key Considerations

• The nodule's stability over a 3-year period is a strong indicator of its benign nature, as malignant lesions are more likely to grow or change over time.
• Chromophobe RCC generally has a favorable prognosis with low metastatic potential, especially for stage 1 disease that was treated with partial nephrectomy, as noted in 1.
• The nodule could represent post-surgical changes, scarring, or a small lymph node rather than recurrent cancer.
• Continued surveillance with periodic imaging is still recommended to ensure the nodule remains stable, as suggested by guidelines such as those outlined in 1 and 1.

Surveillance and Follow-Up

• Guidelines recommend performing CT or MRI of the abdomen at regular intervals after treatment for RCC, as outlined in 1 and 1.
• The use of imaging surveillance with chest radiography or CT annually for up to 5 years after treatment is also recommended, as noted in 1 and 1.
• If there are any concerns, additional imaging modalities like MRI or contrast-enhanced ultrasound may be considered for further characterization of the nodule, as suggested by 1 and 1.

From the Research

Nodule Characteristics

• The nodule is 3mm in size and visible on CT imaging
• Located in the fat anterior to the psoas muscle below the lower pole of the left kidney
• Patient had partial nephrectomy for stage 1 Chromophobe Renal Cell Carcinoma (RCC) 3 years prior

Relevance of Previous Studies

• There are no direct studies on the likelihood of a 3mm nodule being benign in this specific context 2, 3, 4, 5, 6
• However, studies suggest that chromophobe RCC has a favorable prognosis, especially when diagnosed at an early stage 3, 5
• The presence of a small nodule on CT imaging after partial nephrectomy may not necessarily indicate malignancy, as early postoperative imaging can result in abnormal findings that are rarely cancer recurrences 6

Surveillance and Follow-up

• The American Urological Association guidelines recommend imaging within 3-12 months of surgery, but one study suggests that postoperative CT or MRI surveillance can be safely deferred until 1 year after surgery 6
• Regular follow-up imaging is necessary to monitor the nodule and determine if it is benign or malignant 2, 3, 4, 5, 6