|LETTER TO THE EDITOR
|Year : 2018 | Volume
| Issue : 6 | Page : 1444-1445
Primary renal neuroendocrine carcinoma: Diagnosis and treatment dilemmas
Aydin Ciltas1, Osman Sütçüoğlu2, Ramazan Civelek2, Mustafa Benekli1
1 Department of Medical Oncology, Faculty of Medicine, Gazi University, Ankara, Turkey
2 Department of Internal Medicine, Faculty of Medicine, Gazi University, Ankara, Turkey
|Date of Web Publication||28-Nov-2018|
Department of Medical Oncology, Faculty of Medicine, Gazi University, Besevler, Ankara
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ciltas A, Sütçüoğlu O, Civelek R, Benekli M. Primary renal neuroendocrine carcinoma: Diagnosis and treatment dilemmas. J Can Res Ther 2018;14:1444-5
Primary renal neuroendocrine carcinomas (NECs) are extremely rare and have been reported in the literature as case reports. Although the pathologic origin of primary renal NEC is uncertain leading to pathological confusion, it is thought to be caused by an ancestor cell incorporating into the renal parenchyma from a primitive totipotential cell line that differentiates in a neuroendocrine direction. The rarity of this neoplasm has resulted in a relatively limited amount of literature.
We conducted a retrospective chart review of rare cases with renal NEC that spontaneously arose in the kidneys. We investigated the morphological, immunohistochemical, clinical, and therapeutic backgrounds of these cases in light of the available literature. Eligible patients were derived from the Department of Medical Oncology, Faculty of Medicine, Gazi University, Ankara, Turkey. Patients' characteristics are depicted in [Table 1]. All the patients had received chemotherapy treatment for metastatic disease.
Reported poor prognostic factors were older age (>40 years), large tumor size (>4 cm), increased mitotic activity higher than 1/10 high-power field (HPF), tumor extending through the capsule, presence of necrosis, and cytological atypia. Cases with higher mitotic rates of >:2 mitoses/10 HPF developed metastases more frequently., Renal carcinoid tumors have the characteristic features of carcinoid tumors located elsewhere. Conventional methods of imaging are inadequate for detecting smaller carcinoids; therefore, octreotide scintigraphy or Ga-68-labeled positron emission tomography-computed tomography (CT) should complement conventional CT and magnetic resonance imaging when searching for occult or metastatic disease in the postoperative period. Even though surgical resection is the mainstay of the treatment with curative potential, novel treatment modalities for metastatic carcinoid tumors have been reported recently such as somatostatin analogs, everolimus, and radionuclide therapy., In our patients, transabdominal palliative nephrectomy was performed. Macroscopically, the tumors measured 4 cm × 5 cm × 2 cm and 3 cm × 2 cm × 1.5 cm. One of the patients had a sarcomatoid neoplastic component with NEC. To the best of our knowledge, there is no description of NEC with simultaneous sarcomatoid change. Immunohistochemistry revealed that this lesion was stained positive for synaptophysin and CD56, but negative and weakly positive for chromogranin. CD10, CD7, CD20, and neuron-specific enolase were negative. In the metastatic setting, patients were treated with carboplatin + etoposide combination chemotherapy and followed with maintenance somatostatin analog. The patients are doing well with no local recurrence and metastatic progression in 3 years' follow-up.
In conclusion, renal NEC is rare with <100 cases reported in the literature to date. Most of the literatures on renal NEC are based on case reports and small case series. Therefore, their prognosis and management are not predictable and unclear. Since controlled trials are unlikely to be performed, large case series focusing on renal NEC and its treatment are warranted.
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