70 y.o. hispanic male presents to ED with LUQ pain, fever, chills and diaphoresis s/p return from vacation to Mexico. Hx of documented lytic lesion left 10th rib and right 3rd rib on CT scan 1 yr prior. Notes weight loss x 1 year. Denies night sweats.
Denies nausea or vomiting. No hematemesis or hematochezia/melena.
Vitals: Afebrile, HR 82, RR 15, BP 142/89, o2 Sat 97% RA
Gen: Anxious-appearing male in mild discomfort
HEENT: EOMI, no pharyngeal erythema
Cardiac: RRR, no murmurs, rubs or gallops, Normal S1/S2
Lungs: CTA bilaterally
Abd: Mild diffuse tenderness to palpation, no rebound tenderness, BS x 4
Ext: TTP with palpable swelling lateral left 10th rib
WBC 14.5 (no left shift)
BUN 35, Cr 1.9, (+) Microscopic Hematuria
â€˘ PA and Lateral Chest Radiograph
1) Lytic bone lesions of the right posterior 3rd rib and left lateral 10th rib with associated soft tissue masses likely to represent metastatic disease.
â€˘ Bone Scan:
1) Areas of photopenia with subtle regions of increased activity at left antero-lateral 10th rib and right posterior 3rd rib. Cannot exclude metastatic disease.
2)Poorly visualized right renal upper pole - unable to exclude pathologic abnormality.
â€˘ CT Thorax/Abdomen with IV and PO Contrast:
1) Heterogeneous mass involving the superior pole of the right kidney consistent with area of photopenia on bone scan concerning for RCC. Accompanying right adrenal mass and expansile destructive lytic lesions left 10th rib and right 3rd rib concerning for metastasis. Multiple low attenuating cystic structures noted throughout the bilateral kidneys consistent with renal cysts.
Renal Cell Carcinoma
Collecting Duct Carcinoma
Transitional Cell Carcinoma
Differential Dx Cold Lesion on Bone Scintigraphy:
Metastasis- Renal, thyroid, breast, lung
Prostheses or attenuation artifacts
Children- consider infection and neuroblastoma
Dx: Renal Cell Carcinoma with lytic metastasis
Dx Confirmed by: CT and biopsy left 10th rib lesion
RCCâ€™s are usually resistant to chemotherapy and radiation with the best likelihood of cure being surgical resection (radical vs. partial nephrectomy). Unresectable RCCâ€™s have a <20% 5-year survival rate. Cryoprotective nephrectomy can be utilized in patients in good status with metastatic primary disease. Other options include arterial tumor embolization, hormone therapy and immunotherapy. Infrequent but reproducible responses have been noted to a-interferon and IL-2 therapy in combination with anti-angiogenic chemotherapy. Five-year survival is 90-100% when tumor is confined to the renal capsule but drops to <50% when the capsule has been invaded. Metastatic disease to local or distant lymph nodes results in a 10-15% 5-year survival.
Renal cell carcinoma is the most common primary renal tumor in adults (85%) and accounts for 2% of all malignancies. Risk factors include increased age (50-70), smoking history (dose-dependent), male, cadmium/benzene/asbestos exposure, chronic dialysis, excessive phenacetin ingestion and hereditary genetic predispositions. Bilateral RCCâ€™s are more common in von Hippel-Lindau, Tuberous Sclerosis and familial RCC, however bilateral disease occurs in only 2% of patients. Unilateral disease is multi-centric in 25% of all diagnosed.
Malignant cells arise from the proximal tubular epithelium and are located in the renal cortex with multiple pathologic subtypes to include clear cell (75%), papillary, granular and collecting duct carcinoma. Imaging often reveals the heterogeneity of these tumors ranging from completely cystic to solid. Staging can be accomplished with either the TNM (Tumor, Node, Metastasis) system or the Robson criteria:
TNM Guidelines - considered to be more precise due to clear definition of anatomic extent of the tumor
â€˘ Stage 1 RCCs are 7 cm or smaller and confined to the kidney.
â€˘ Stage 2 RCCs are larger than 7 cm but still organ confined.
â€˘ Stage 3 is subdivided into three groups:
- T3a involves perinephric fat
- T3b extension into the renal vein or vena cava, involve the ipsilateral adrenal gland,or have spread to one local lymph node.
- T3c tumor involves infradiaphragmatic IVC
â€˘ Stage 4 tumors extend beyond the Gerota fascia, to more than one local node or have distant metastases
I Tumor confined within the renal capsule.
II Invasion into perinephric fat but contained within the Gerota Fascia (involvement of ipsilateral adrenal gland).
IIIA Invasion of renal vein or IVC (w or w/o venous thrombus)
IIIB Regional lymph node involvement
IIIC Invasion of both renal vein/IVC and regional lymph nodes
IVA Direct invasion of adjacent organs
IVB Distant metastases
Renal cell carcinoma is diagnosed incidentally in 50% of cases and often presents with flank pain, mass, hematuria (gross vs. microscopic) or noted on imaging. Secondary findings include weight loss, fever, hypertension, hypercalcemia and a variety of paraneoplastic syndromes. CT is the most valuable imaging modality to confirm size and involvement of local structures with 91% accuracy in staging.
Bosniak Guidelines for Evaluation of Cystic Renal Masses on CT
I) Simple, benign cysts with homogeneity, water density and a sharp interface without wall thickness, calcification or enhancement
II) Cystic with one/two thin septations, thin/fine calcifications and hyperdense benign lesions
IIF) Need f/u secondary to minimally complicated cysts
III) Indeterminate cystic masses requiring surgical evaluation due to wall thickness, nodularity, thick/ irregular peripheral calcifications with multilocular enhancing septa
IV) Non-uniform, thick, enhancing wall with large nodules and solid components.
Often appears as a heterogeneous exophytic mass with distortion of the renal contour secondary to hemorrhage and necrosis. Metastatic disease involves direct local invasion of the adrenal glands, liver, spleen, colon and pancreas with local lymphadenopathy. RCCâ€™s can extend into the renal vein and ultimately the IVC resulting in thrombosis. The lungs as the #1 site for distant metastasis. Skeletal lesions are purely lytic in nature, well-defined as a focal photopenic defect on Technetium 99m MDP bone scan.
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