Kidney Medullary Carcinoma; Medullary Carcinoma of the Kidney; Medullary Renal Cell Carcinoma; RMC

Renal medullary carcinoma (RMC) is a rare but aggressive type of kidney cancer. Its a very rare subclass of renal cancer that is largely restricted to individuals who carry the sickle cell trait, sickle cell disease, or other sickle hemoglobinopathies that can cause sickling of the red blood cells. Generally, about 80% of cases have metastatic disease present at diagnosis. Individuals without initial metastatic disease almost universally develop metastatic spread. RMC cells lack a protein called INI1 or SMARCB1. This protein is a tumor suppressor and normally helps prevent cells from becoming cancerous.

RMC develops in the innermost part of the kidney (medulla). Its main function is to maintain the bloods water and salt balance.

Diagnostic testing: Diagnostic testing for RMC may include:

• •

  Physical exam and history;

• •

  Hemoglobin electrophoresis;

• •

  Immunohistochemistry (IHC) testing showing INI1/SMARCB1 loss with or without confirmation by fluorescence in situ hybridization (FISH) testing or next-generation sequence (NGS) testing;

• •

  Blood chemistry studies;

• •

  Urinalysis;

• •

  Liver function tests;

• •

  Ultrasound exam;

• •

  Computed tomography (CT) scan;

• •

  Magnetic resonance imaging (MRI); and

• •

  Biopsy.

Physical findings: Symptoms of RMC include:

• •

  Blood in urine;

• •

  Flank pain;

• •

  Loss of appetite;

• •

  Unexplained weight loss;

• •

  Fever;

• •

  Night sweats;

• •

  Abdominal mass;

• •

  Low red blood cell count; and

• •

  Swelling in the lower body.

ICD-9: 189.0

ICD-10: C64.1; C64.2; C64.9

The current median of survival for individuals with RMC is about 13 months. Generally, by the time most individuals are diagnosed the cancer has spread to the lymph nodes or other organs. The survival rate is within two years regardless of treatment and therapy.

Many of the therapies that are used for other kidney cancers do not work against RMC. Due to the rarity of the disease, there is no standard of care. However, platinum-based combination chemotherapy is typically the initial treatment I with subsequent consideration for surgery or additional chemotherapy. Other specific therapeutic procedures may include radiation therapy, targeted therapy, immunotherapy, or other therapies on a case-by-case bases.

Suggested MER for Evaluation:

• •

  Clinical history and physical examination;

• •

  Results of imaging (CT scan, MRI, ultrasound); and

• •

  Biopsy to determine if the SMARCB1 gene is present or nonexistent.

Suggested Listings for Evaluation:

Metastatic disease is typically present at diagnosis and should be evaluated under listing 13.21B.