Rare (<1%) histological subtypes of renal cell carcinoma: an update

Huge mucinous tubular and spindle cell carcinoma of the kidney: A case report

Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a rare type of kidney cancer. Accurate diagnosis depends on pathological examination. A huge left renal tumor was incidentally found by computed tomography (CT) examination of a 52-year-old lady. She underwent Laparoscopic radical left nephrectomy. The postoperative pathological diagnosis is Mucinous tubular and spindle cell carcinoma. Eight months later, she showed no signs of recurrence.

Imaging findings for mucinous tumors of the abdomen and pelvis

This article aims to describe the imaging findings for mucinous tumors of the abdomen and pelvis, which have a similar appearance on imaging tests regardless of the organ in which they develop. Due to the high water content of mucus, the appearance of these tumors is generally similar to that of water on ultrasonography, computed tomography, and magnetic resonance imaging. Another common feature of mucin-producing tumors is that calcifications are often present. The rupture of these lesions and accumulation of mucinous material in the peritoneal cavity gives rise to pseudomyxoma peritonei. It is important to identify mucinous tumors because they have a different prognosis and clinical course than non-mucinous tumors and require different management. Depending on their anatomic location and their imaging characteristics, the treatment approach varies from follow-up to radical surgery together with chemotherapy or radiotherapy or both.

Renal Medullary Carcinoma; A Rare Entity

Renal medullary carcinoma (RMC) is an uncommon aggressive neoplasm of the kidney. RMC is biologically aggressive with a very poor prognosis, and metastasis is seen in up to 95% of the patients at diagnosis or shortly thereafter. The common sites of metastasis are respectively lymph nodes, lungs, livers, and adrenal glands in order of frequency. The presence of poorly differentiated eosinophilic cells in a characteristic fibro-inflammatory stroma is seen in histological examination. The origin and pathogenesis of RMC are unclear. The radiographical and pathological findings suggest that RMC probably originates in the calyceal epithelium in or near the renal papillae, which could be the result of chronic ischemic damage in the renal papillae epithelium by sickled erythrocytes. Positivity of VEGF and HIF-1α supports the chronic hypoxia that may be caused in the pathogenesis of RMC. Other factors such as genetic or environmental factors are important. Although hemoglobinopathy is very common, RMC is very rare. An understanding of the molecular and genetic factors of this rare disease is important for its prevention and treatment. We herein describe an adult Turkish patient, who presented with hematuria. The diagnosis was RMC after pathological examination.

The spectrum of renal cell carcinoma in adults

The spectrum of renal cell carcinoma (RCC) includes many neoplasms with distinct cytogenetics, biologic behaviors, and imaging appearances. The advent of molecular therapies targeting different tumor types, new insights into the relative roles of biopsy and surveillance for small incidental tumors, and a growing array of nephron-sparing interventions have altered management of RCC. Similarly, the role of the radiologist is changing, and it is becoming increasingly important for radiologists to familiarize themselves with the various types of RCC. This article introduces the reader to the common and uncommon recognized types of renal cell carcinoma and discusses how these neoplasms differ in imaging appearance and behavior.

Renal cell carcinoma: staging and surveillance

Renal cell carcinoma is a common malignancy with many histologic subtypes. Appropriate treatment depends not only upon the specific subtype but also the size of the tumor and extent of spread at time of presentation. Approximately 5% of RCCs are part of a hereditary syndrome which must also be considered in the therapeutic decisions. Although some RCCs are detected with ultrasound, CT or MR is required for staging. CT is used most commonly as it is most readily available and relatively less expensive than MR imaging. The TNM classification of the American Joint Committee on Cancer has largely replaced the Robson classification. Early detection, accurate staging, and improved treatment options have resulted in improved 5-year survival of patients with renal carcinoma.

TGF-β1-induced Fascin1 promotes cell invasion and metastasis of human 786-0 renal carcinoma cells

OBJECTIVE

To investigate the effect of transforming growth factor-β1 (TGF-β1) on the expression of Fascin1 protein and its impact on cell invasion and metastasis in human renal carcinoma.

METHODS

Renal tissue slices of 52 cases when undergoing radical nephrectomy were collected to be the observation group, and the normal renal tissues of 23 cases when undergoing nephrectomy due to trauma were collected to be the control group. The expressions of TGF-β1 and Fascin1 were measured by immunohistochemical staining. Human renal carcinoma 786-0 cell line was selected as the study subject. The cells were divided into six groups including NT (no transfection), si-NC (transfection with pGenesil-1-con) si-Fascin1 (transfection with pGen-1-FSCN1) groups, and three corresponding groups: NT, si-NC and si-Fascin1 groups treated with TGF-β1. RT-qPCR, Western-Blot, Transwell, and flow cytometry method were used in this study.

RESULTS

The expressions of TGF-β1 and Fascin1 in the observation group were significantly higher than those in the control group. The expression of TGF-β1 was positively correlated with that of Fascin1. After 24 and 48h of treatment with TGF-β1 (10ng/mL), the invasive and metastatic abilities of the 786-0 cells in the NT and si-NC groups were higher than those before the treatment (P<0.05). Comparing the three groups before TGF-β1 treatment, the invasive and metastatic ability of 786-0 cells in the si-Fascin1 were significantly lower than those in the NT group and si-NC group (P<0.05).

CONCLUSION

TGF-β1 could induce the expressions of 786-0 Fascin1 mRNA and protein and thus improve the invasive and metastatic ability of human 786-0 renal carcinoma cell.

Impact of histologic subtype and sarcomatoid transformation on metastasis in renal cell carcinoma: a single institute experience in 149 patients

PURPOSE

To compare the metastatic pattern and outcome of clear cell RCC (ccRCC) and papillary RCC (pRCC), and to assess the impact of sarcomatoid transformation on the disease spread and prognosis.

MATERIALS AND METHODS

This IRB-approved, HIPAA-compliant retrospective study included 149 consecutive patients (108 men; mean age 58 years; range 25-86) with metastatic RCC (ccRCC = 116, pRCC = 33), identified from imaging database. All available imaging studies and electronic records of these patients were reviewed to document pathological features, distribution and timing of metastasis, and survival. The metastatic pattern and survival was first compared between the ccRCC and pRCC groups, and then between those with and without sarcomatoid transformation; all 27 cases of sarcomatoid transformation occurred in the ccRCC group.

RESULTS

Metastases were noted at presentation in 62 (42%) and after median 13 months in the remaining 87 (58%) patients. Lymph nodes (134/149), lung (125/149), and bone (60/149) were the most common metastatic sites, which did not differ between the RCC subtypes. Pancreatic (p = 0.0014) and renal (p = 0.046) metastases were more common in ccRCC, lymphangitic spread (p = 0.0003) and peritoneal metastasis (p = 0.039) more common in pRCC. In ccRCC, sarcomatoid transformation was associated with high-grade tumors (p < 0.0001), more frequently demonstrated lymphangitic (p = 0.016), pleural (p = 0.0018), and peritoneal metastases (p = 0.0002), and had shorter metastasis-free survival and overall survival (log-rank test, p < 0.0001). In the absence of sarcomatoid transformation, ccRCC had longer metastasis-free interval (median 22 months compared to 6 months) (p = 0.0238) and overall survival (median survival 48 months vs. 25 months) (p = 0.0193) compared to pRCC.

CONCLUSION

Histologic subtype, as well as the presence of sarcomatoid transformation, affects the metastatic pattern and metastasis-free survival of RCC. In the absence of sarcomatoid transformation, ccRCC has a better outcome than pRCC.