Azathioprine-induced squamous cell carcinoma of the kidney

A case report of complete pathological remission after chemotherapy in a patient with primary renal squamous cell carcinoma

This is the first case report of the outcomes of systemic chemotherapy in a patient with locally advanced renal squamous cell carcinoma, a rare tumor, as well as the first next generation sequencing study of this rare tumor. The patient's main symptoms were fever and low back pain. Initial positron emission tomography and computed tomography (PET-CT) suggested a malignant renal tumor at onset, but biopsy confirmed renal squamous cell carcinoma. Next generation sequencing showed a low level of microsatellite instability (MSI-L), a high tumor mutational burden (TMB-H), a high neoantigen burden (TNB-H), and a strong loss of heterozygosity (LOH) for human leukocyte antigen (HLA), with 67 deleterious mutations. The patient achieved partial radiological remission after a cycle of systemic chemotherapy with albumin-bound paclitaxel combined with nedaplatin. After radical resection of the left renal tumor, postoperative pathology confirmed complete tumor remission and tumor-like xanthogranulomatous pyelonephritis. Conclusion: This renal squamous cell carcinoma patient responded to systemic chemotherapy with paclitaxel combined with platinum, providing a reference for the future treatment of similar cases. Pathology and gene sequencing indicated that renal squamous cell carcinoma occurred in a background of active inflammation and that the tumor evolved immune escape mechanisms such as loss of HLA heterozygosity, with gene repair defects and TMB-H.

[A case of squamous cell carcinoma of the breast in a patient with Crohn's disease taking azathioprine]

Azathioprine (AZA) treatment in transplant or autoimmune patients and subsequent appearance squamous cell carcinomas at various sites, particularly skin and cervix, has shown a close relationship. However, it remains uncertain whether this is true for the patients with Crohn's disease. We report a case of squamous cell carcinoma of the breast occurred in a 35-year-old female with Crohn's disease taking AZA. She was first diagnosed with Crohn's disease 10 years ago and has taken AZA with 5-aminosalicylic acid (5-ASA) on regular follow up in gastrointestinal department for 9 years. She had no family history of breast cancer. She visited breast cancer clinic due to incidentally found right breast mass. A mastectomy on the right breast was performed and 6.3×5.5 cm mass was removed. The mass was microscopically proven to be poorly differentiated squamous cell carcinoma with focal keratin pearl formation. At age of 25, she was first diagnosed with active Crohn's disease. 5-ASA and corticosteroid induced remission. Then, steroid was tapered off and AZA was maintained at 1 mg/kg due to leukopenia at higher dose. She stopped taking AZA at her discretion during her two pregnancies and reported total of 67 months of AZA medication on her breast cancer diagnosis.

Squamous cell carcinoma of the renal pelvis associated with kidney stones: a case report

A 70-year-old female with a long-standing history of kidney calculi presented with vague abdominal pain. Work-up included a CT and MRI of the kidneys. A mass was demonstrated in the superior pole of the left kidney. The mass was biopsied percutaneously under CT guidance. Pathology revealed a poorly differentiated carcinoma, but was inconclusive for a definitive cell type. The patient subsequently underwent a nephrectomy that revealed squamous cell carcinoma of the renal collecting system. She had an uneventful postoperative recovery. Chronic renal calculi pose a risk for the development of squamous metaplasia that may lead to squamous cell carcinoma. Although this malignancy is rare in the upper urinary tracts, patients with long-standing nephrolithiasis should be monitored. This diagnosis should be included in one's differential when evaluating a renal mass that is associated with chronic inflammatory conditions.