Renal cell carcinoma initially presenting as an arteriovenous malformation: a case presentation and a review of the literature

Crisis Averted: Clinical T1b Renal Mass with Concurrent Arteriovenous Malformation and Renal Vein Thrombus

Arteriovenous malformations (AVMs) secondary to renal-cell carcinoma (RCC) are well-described in the literature. Independently, renal vein and inferior vena cava tumor thrombi can be detected in locally-advanced RCC. A 67-year-old gentleman presented with a cT1b renal mass detected on workup for elevated creatinine. Multiphase CT imaging obtained for partial nephrectomy surgical-planning revealed an initially-missed renal cortical AVM. This drastically changed the plan for intervention, including use of an open approach with AVM embolization by interventional radiology prior and avoidance of a nephron-sparing approach. Final pathology confirmed the AVM and a subclinical renal vein thrombus masked by arterial flow on CT imaging, making this the first concurrent case described in the literature. Herein, we describe avoidance of catastrophic intraoperative hemorrhage by careful review of preoperative imaging and provide a literature review of imaging modalities for both renal surgical-planning and detection of tumor thrombi in RCC.

The Spinal Dural Arteriovenous Fistula in a Patient With Metastatic Renal Cell Carcinoma

Spinal dural arteriovenous fistula (SDAVF) is an elusive and underdiagnosed disease. Congestive myelopathy occurs from increased venous pressure transmitted by the fistula between a radiculomeningeal artery and the spinal venous plexus. While its cause remains unknown, associations between SDAVF and hyper-vascular states have been reported. We present the first documented case report of a de novo SDAVF diagnosis in a patient with active renal cell carcinoma (RCC) metastasis to the spinal epidural space and review the literature.

A case of duodenal hemorrhage due to arteriovenous malformation around a serous cystic neoplasm

Background

No reports have so far described arteriovenous malformation (AVM) in the pancreas caused by a tumor. We herein report a case of pancreatoduodenectomy for a patient who developed duodenal hemorrhage due to AVM developed around serous cystic neoplasm (SCN) of the pancreas.

Case presentation

A 79-year-old man was referred to our hospital because of anemia (Hb 7.4 g/dl) and pancreatic head tumor. Computed tomography showed microcystic-type SCN, 87 mm in size, in the pancreatic head. Vascular hyperplasia had developed around the cystic lesion. Upper gastrointestinal endoscopy and colonoscopy did not reveal the cause of anemia, so the patient was followed closely without hemostatic therapy. Iron preparations had improved the anemia. Three months later, the patient developed anemia (Hb 5.8 g/dl) again. Gastrointestinal endoscopy showed oozing from the mucosa in the duodenum via the swollen vascular hyperplasia. He was diagnosed as duodenal hemorrhage from the blood vessels around SCN. Pancreatoduodenectomy was performed to control repeated duodenal bleeding. A histopathological examination revealed that the cystic lesion in the pancreatic head was SCN, and the AVM developed around SCN and duodenum, causing repeated duodenal hemorrhage. The patient was discharged on postoperative day 22. Nine months after surgery, the patient had no recurrence of anemia.

Conclusions

There have been no reports of duodenal hemorrhage due to acquired pancreatic AVM around pancreatic tumor, including SCN. We successfully treated a case of duodenal hemorrhage due to pancreatic AVM around SCN by pancreatoduodenectomy.

Arteriovenous malformation and thyroid metastasis from underlying renal cell carcinoma, an unusual presentation of malignancy: A case report

Renal Clear Cell Carcinoma (RCC) comprises over 80% of renal malignancies in adults. Thyroid gland metastasis is rare in RCC. Few studies have described cases of RCC mistaken for benign arteriovenous malformation (AVM). To the best of our knowledge, an AVM arising from underlying RCC metastasis to the brain has not yet been reported. The current study presents a case of RCC metastasis to the thyroid gland, with an AVM identified to be a result of metastatic involvement in the brain. A 45-year-old African-American female presented with left-sided weakness, slurred speech, facial droop and seizure. The patient's medical history was notable for a diagnosis of RCC, 2010 American Joint Committee on Cancer Tumor-Node-Metastasis Stage 1B (T1B, N0, M0) grade III status post-right partial nephrectomy. Computed tomography (CT) imaging revealed a soft-tissue mass, suspected to be metastasis, in the left lobe of the thyroid, in addition to a 1.9 cm right intracranial mass in the parietal lobe. Positron emission tomography/computed tomography revealed a hypermetabolic area in the thyroid. Fine needle aspiration of the thyroid, and subsequent histopathological analysis, suggested a diagnosis of RCC metastasis. Subsequent immunohistochemical analysis of the thyroid tumor confirmed RCC metastasis. The patient also underwent a right partial craniotomy with resection of the intra-axial mass. Initial pathology was suggestive of an AVM. After several months, the patient was readmitted with headache, nausea and vomiting. Repeat imaging revealed recurrence of a 3.9 cm mass that was negative for AVM on biopsy; however, the immunostaining markers were positive for RCC. Recent literature suggests a link between AVMs and RCC as each exhibit highly vascular characteristics. RCC is a particularly vascular tumor that has been demonstrated to lead to the abnormal expression of various angiogenesis-promoting growth factors, including vascular endothelial growth factor. These angiogenic factors are vital to the pathophysiological pathway involved in the tumorigenesis and progression of RCC, and may explain the development of AVMs within these neoplasms, as demonstrated in the case presented in the current study.