Case Presentation: A 30-year-old woman with sickle cell trait and recent history of preeclampsia, pregnancy loss, and deep vein thrombosis presented to the emergency room with right upper quadrant pain. The pain was new, rated ten on a ten-point severity scale, and non-radiating. She also endorsed progressively worsening cough over several months and new, right-sided chest pain without shortness of breath. She had been taking rivaroxaban for her DVT until she ran out of the medication 2 weeks earlier. On initial presentation, vital signs were normal, and physical exam revealed deep cervical and supraclavicular lymphadenopathy and trace bilateral lower extremity edema. Labs were remarkable for hemoglobin of 9.9 g/dL, which was stable from prior labs. Basic metabolic panel, liver panel, and lipase were normal. Chest x-ray showed right paratracheal and possible hilar lymphadenopathy. D-dimer came back elevated at 4.68 µg/mL. CT angiogram demonstrated acute lobar and segmental pulmonary emboli in the left lower lobe, as well as mediastinal and hilar lymphadenopathy and multiple bilateral pulmonary nodules. The patient was admitted, and anticoagulation was started.A broad workup for a differential including fungal infection, tuberculosis, sarcoidosis, and malignancy returned with a negative Histoplasma antigen and antibody, Blastomyces antibody, and QuantiFERON gold. Angiotensin-1-converting enzyme assay and serum and urine calcium were within normal limits. Fine needle biopsy of a cervical node was performed, and pathology was consistent with renal medullary carcinoma. Subsequent CT chest, abdomen, and pelvis showed a right-sided renal mass as well as evidence of metastatic disease to the lungs, liver, and lymph nodes.Cytotoxic chemotherapy with paclitaxel, carboplatin, and gemcitabine yielded some response, but ultimately this regimen was discontinued due to severe neutropenia and anorexia. Nephrectomy was not pursued because of the extent of metastatic disease. Second line therapies with PARP inhibitor olaparib and then nivolumab were trialed without response, leading to hospice referral. The patient ultimately died 9 months after diagnosis at the age of 31.
Discussion: Renal medullary carcinoma (RMC) is diagnosed almost exclusively in patients with sickle cell trait. While sickle cell trait is relatively common and generally thought to be benign, RMC is an aggressive and rare cancer, with under 300 cases reported in literature. RMC is usually found in young adults, is more common in men, and more commonly arises in the right kidney. There are limited early signs or symptoms of disease. RMC may present with the classic triad of flank pain, hematuria, and a palpable mass as other renal carcinomas, but patients usually present with metastatic disease at diagnosis (1). Patients may have hematuria preceding diagnosis by several months, but given the rarity of disease, routine screening is not standard unless urinalysis is performed for other reasons. There is limited evidence for treatment regimen, but platinum-based cytotoxic chemotherapy has been shown to have a modest palliative benefit (2). As most present with advanced disease, average survival is thirteen months with treatment (3).
Conclusions: Renal medullary carcinoma, although rare, should be high on the differential when a young patient with sickle cell trait presents with diffuse lymphadenopathy concerning for a metastatic process. As it carries a very poor prognosis, early diagnosis is key to initiate chemotherapy as soon as possible.