Clear Cell Lesions Research Articles

Diagnostic Utility of EWSR1 in Clear Cell Odontogenic Carcinoma: A Systematic Review.

In the 2022, World Health Organisation classification of odontogenic tumours, the clear cell odontogenic carcinoma is designated as a malignant odontogenic tumour with high recurrence and aggressive behaviour. Deceptive behaviour in the context of a wide range of differentials presents a significant diagnostic problem. It is the fifth most commom type of malignant odontogenic tumor. A systematic assessment of published cases, case series, and retrospective investigations of diagnostic significance of EWSR1 gene in clear cell odontogenic carcinoma is presented to determine trends in presentation, diagnostic characteristics, treatment, and patient outcome. To locate papers reporting clear cell odontogenic carcinoma and EWSR1, extensive database searches were carried out. Demographics, tumour location, immunohistochemical and molecular tests, treatment, follow-up, and recurrence were the variables. 34 cases were detected; 52.9% (n = 18) of the cases were females. The average age was 62.5years, with a range of 43-82years. The average size ranged from 3.4 to 8cm. The mandibular body was the most common location, followed by the maxilla. Maximum immunohistochemistry positivity revealed by CK 19, CKAE1/3, EMA and p63. Most common gene fusion detected was EWSR1-ATF1 in 62.4% of cases contributing to its diagnostic attributes. Surgical treatment was used in 97% of cases. The average follow-up period was 30.3months, and recurrence was reported in 52.4% of the cases. CCOC can metastasize, and the prognosis is fair. This is first systematic review, where we have attempted to consolidate the mutational expression of EWSR1 in Clear cell odontogenic carcinoma. It is difficult to identify from other clear cell tumours of the head and neck region. It is crucial to distinguish it from other clear cell lesions because of its aggressiveness.

Diagnostic Approach to and Differential Diagnosis of Clear Cell and Glandular Lesions of the Lower Urinary Tract.

A variety of glandular and clear cell lesions may be seen in the urinary bladder and/or urethra, ranging from benign to malignant primary and secondary tumors. Lesions with no malignant potential include reactive processes, such as nephrogenic metaplasia, and may show similar morphologic features as an infiltrative neoplasm, particularly in small biopsies. Similarly, ectopic tissues of Müllerian origin may be seen in the lower urinary tract, and their distinction from a true glandular neoplasm is essential to avoid overtreatment. A wide variety of primary and secondary malignant tumors exist with varying degrees of glandular and clear cell features. Therefore, surgical pathologists must be aware of the full scope of possible lesions to avoid misdiagnosis. To provide a practical framework for approaching the diagnosis of clear cell and glandular lesions of the urinary bladder/urethra and prostate, highlighting the strengths and limitations of various diagnostic features and ancillary tests. A review of the current literature was performed to obtain data regarding up-to-date diagnostic features and ancillary studies. In summary, distinct morphologic and immunohistochemical features and clinical and radiologic correlation are essential to establish an accurate diagnosis when such cases with glandular and clear features are encountered in the lower urinary tract.

An unusual presentation of oral metastasis of mucinous colorectal adenocarcinoma: A rare clinical entity and diagnostic challenge

ABSTRACT Mucinous colorectal adenocarcinoma represents a distinctive variant of colorectal carcinoma (CRC), which is typified by copious amounts of extracellular mucin. This subtype of CRC is distinguished by the presence of mucin, which constitutes at least 50% of the tumor volume, thus serving as a defining histologic feature of this malignancy. Colorectal carcinoma patients may develop lymphocytic and hematogenous metastases. While surgery is the only curative treatment option available, the use of chemotherapy, radiation therapy, or a combination of both can help improve the prognosis. However, the risk of recurrence remains substantial, in terms of both locoregional and distant spread. This article reports a gingival metastatic carcinoma of colorectal mucinous adenocarcinoma in a 24-year-old woman. Microscopically, architectural and cellular features resulted in ruling out differentials. Oral metastases are an infrequent phenomenon that can arise within either the soft tissues or the osseous structures of the oral cavity. This metastasis can exhibit clinical and radiographic features that are reminiscent of clear cell lesions localized in the head and neck region.

Top 10 Clear Cell Head and Neck Lesions to Contemplate.

Optically clear cytoplasm may occur in neoplastic and non-neoplastic conditions, either as a characteristic feature of a disease entity or as a morphologic rarity, potentially creating diagnostic dilemmas in various organ systems. In the head and neck, clear cell change can occur in lesions of salivary, odontogenic, thyroid, parathyroid, or sinonasal/skull base origin, as well as in metastases to these regions. This review elaborates the top ten clear cell lesions in the head and neck, emphasizing their distinguishing histologic, immunohistochemical, and molecular attributes, and presents a rational approach to arriving at an accurate classification. Cytoplasmic pallor or clearing may be caused by accumulations of glycogen, lipid, mucin, mucopolysaccharides, water, foreign material, hydropic organelles, or immature zymogen granules. Overlapping morphologic features may present a diagnostic challenge to the surgical pathologist. Similarity in immunohistochemical profiles, often due to common cell type, as well as rare non-neoplastic mimics, furthers the diagnostic conundrum. The top ten lesions reviewed in this article are as follows: (1) clear cell carcinoma (salivary and odontogenic), (2) mucoepidermoid carcinoma, (3) myoepithelial and epithelial-myoepithelial carcinoma, (4) oncocytic salivary gland lesions, (5) squamous cell carcinoma, (6) parathyroid water clear cell adenoma, (7) metastatic renal cell carcinoma (especially in comparison to clear cell thyroid neoplasms), (8) sinonasal renal cell-like adenocarcinoma, (9) chordoma, and (10) rhinoscleroma.

A new insight into the classification of clear cell lesions of the oral cavity based on the diagnostic modalities used – A review

A new insight into the classification of clear cell lesions of the oral cavity based on the diagnostic modalities used – A review

ODP098 Hyperparathyroidism Caused by Two Large Water Clear Cell Adenomas

Abstract Background In ambulatory settings, primary hyperparathyroidism is the most prevalent cause of hypercalcemia. Approximately 85% of primary hyperparathyroidism cases are caused by a solitary parathyroid adenoma; other causes include diffuse parathyroid hyperplasia, multiple parathyroid adenomas, and parathyroid cancer. Chief cell adenomas are the most prevalent; adenomas can also consist of oxyphil cell adenomas, lipoadenomas, or mixed cell adenomas. Water clear cell adenoma (WCCA) is a rare tumor formed of large clear cells with foamy pink cytoplasm. Fewer than 30 cases have been recorded in the literature. Case A 52-year-old male with polyuria and polydipsia, diagnosed with hypercalcemia was referred to an endocrinologist. His calcium was 10.9 mg/dl, corresponding parathyroid hormone (PTH) 74 pg/ml, 24-hour urine calcium 818 mg/24hr, vitamin D 25–hydroxy 24.2 ng/ml. He was referred to an endocrine surgeon. A 4-dimensional CT scan revealed soft tissue masses posterior to the thyroid and in the tracheoesophageal groove, consistent with potential parathyroid masses. In the operating room, baseline intraoperative PTH (ioPTH) was 371 pg/ml. A large left superior gland was removed from its normal position, and the ioPTH dropped to 104 pg/ml at 10 minutes post-resection, followed by a rise to 525 pg/ml. A large descended (ectopic) right superior gland was then identified and resected, and the ioPTH decreased to 72, 44, and 57 pg/ml at 10, 15 and 20 minutes post-resection. The remaining parathyroid glands were not identified due to adipose tissue in the neck and likely gland suppression in the setting of high PTH. The pathology report of the two excised glands (left superior 3.2×1.7×0.5cm and 3.703g, right superior 3.4×1.3×0.4cm and 1.86g) demonstrated water clear cell tissue. Post-operatively, patient's polyuria and polydipsia resolved. Labs collected 3 months after surgery demonstrated normalization of the calcium and PTH. The patient was advised to continue follow up every six months. Conclusion Water clear cell parathyroid adenomas are extremely rare. Water clear-cell lesions are considered indolent because excised adenomas are markedly larger than conventional adenomas and grow to a considerable size before becoming biochemically active and diagnosed. Clinical presentation of water clear cell parathyroid lesion is like other causes of primary hyperparathyroidism. The only way to diagnose is via histopathological examination. In rare cases, clear cell renal carcinoma can metastasize to the parathyroid gland causing a similar presentation. Additionally, the rate of hypercalcemia recurrence is higher in WCCA as compared to chief cell adenoma. Therefore, closer follow up of these patients is recommended. Reporting additional cases will aid in our understanding of this uncommon entity, elucidating possible causes/associations, natural history, typical appearances, and post-treatment prognosis. Presentation: No date and time listed

Clear cell squamous cell carcinoma of the tongue exhibits characteristics as an undifferentiated squamous cell carcinoma

Clear cell squamous cell carcinoma (CCSCC), where cells show abundant clear cytoplasm, –is a variant of squamous cell carcinoma (SCC) and a rare entity in the oral cavity. The characteristics of CCSCC, especially in immunohistochemical features, remain unclear. We characterized a case of CCSCC arising from the oral mucosal epithelium of tongue, where the clear cell lesion accounted for a predominant portion of the tumor. This CCSCC, which was partially surrounded by conventional SCC, exhibited cellular atypia immunohistopathologically and histopathologically with a high Ki-67 index, increased number of mitotic figures and enlarged nuclei. Intravascular invasion of the carcinoma cells was also observed. Furthermore, the CCSCC recurred and metastasized to the cervical lymph nodes and both lungs three months after resection. Immunohistochemical analyses demonstrated decreased expression of p40 (an isoform of SCC marker p63), ADP-ribosylation factor (ARF)-like 4c (ARL4C), yes-associated protein (YAP) and 5-methylcytosine (5mC) in the CCSCC lesion compared with the surrounding SCC lesion, where the expression of ARL4C was upregulated compared with non-tumor region and YAP showed nuclear translocation. In addition, siRNA loss-of-function experiments revealed that p63 expression was required for ARL4C expression and DNA methylation was induced by p63 and YAP/transcriptional co-activator with PDZ-binding motif (TAZ) signaling in oral SCC cell lines. These results suggest that CCSCC, in which several markers of SCC-associated intracellular signaling pathways are downregulated, together with evidence of altered epigenetic regulation, is characterized as an undifferentiated SCC variant.

Clear Cell Proliferations of the Skin: A Histopathologic Review.

Cutaneous clear cell proliferations encompass a heterogenous group of several primary cutaneous neoplasms and metastatic tumors with different histogenesis. Many of these clear cell proliferations may seem strikingly similar under the microscope resulting in challenging diagnosis. In many of these clear cell lesions, the reason for the clear or pale appearance of proliferating cells is unknown, whereas in other ones, this clear cell appearance is due to intracytoplasmic accumulation of glycogen, mucin, or lipid. Artifacts of tissue processing and degenerative phenomenon may also be responsible for the clear cell appearance of proliferating cells. Awareness of the histopathologic findings as well as histochemical and immunohistochemical techniques are crucial to the accurate diagnosis. This review details the histopathologic features of clear cell cutaneous proliferations, classifying them according their type of differentiation and paying special attention to the histopathologic differential diagnosis among them.

Clear cell lesions in pathology: Histomorphologic approach to diagnosis.

There has been remarkable progress in the field of surgical pathology; however, histomorphology has remained the most important and essential tool of the surgical pathologist in everyday practice till now. It is surprising that the hematoxylin-eosin (H and E) stain, introduced more than a century ago, has still remained the gold standard stain for histological examination and diagnosis of human diseases. Besides different findings or clues observed in histopathology sections like inclusions, granules, grooving, globules, halo, or clearing, which would enable the pathologist to provide a precise and accurate diagnosis; observation of clear cells is one of the important findings and clue for reporting. It may also sometimes lead to difficulties and delays in establishing the diagnosis. It can be focal or extensive and primary or rarely it may be secondary. Clear cell changes may be observed in many non-neoplastic, benign, or malignant tumors of diverse origin. Clear cell tumors contain a preponderance of clear cells. It can be seen in almost all the organs of human body and can be classified according to location or biological behavior. Commonly seen clear-cell tumors are usually malignant and common organs involved are female genital tract, urogenital tract, head and neck areas, central nervous system, skin, and rarely in bone and soft tissues. For approach to clear cell lesions, one has to decide if the change is artifactual, a mimic of clear cell tumors, or a clear cell tumor in reality. Once the mimics and artifactual/degenerative changes have been ruled out, a tumor either primarily of clear cell origin or showing secondary change has to be decided. The tumor next is to be diagnosed as benign/malignant and epithelial/mesenchymal based on morphology.

Evaluation to Differentiate between Tumor Lesions and the Parenchyma in Partial Nephrectomies for Renal Tumors Based on Quantitative Fluorescence Imaging Using Indocyanine Green Dye

Introduction: Near-infrared fluorescence imaging with indocyanine green is a useful tool during partial nephrectomy. Because an accurate method for judging hasn't been established yet, the success rate may be slightly different and inconsistent. Materials and Methods: A total of 21 cases with suspected renal cancers who had undergone a partial nephrectomy were enrolled. We examined differences in the success rate between malignant lesions and the parenchyma by quantifying fluorescence in the pre-resection and ex vivo phases. Results: Pre-resection imaging showed a significant degradation of fluorescence in the focused lesion in 76.2% (16/21) of cases. A significant degradation was observed in 73.7% (14/19) of the total malignant lesions, 70.5% (12/17) of cases with a clear cell lesion, 100% (2/2) of cases with non-clear cell lesions, and 100% (2/2) of benign angiomyolipomas. In contrast, imaging of the ex vivo resected specimens showed a significant degradation in fluorescence of the focused lesions in 85.7% (18/21) of cases. A significantly degradation was observed in 84.2% (16/19) of the total malignant lesions, 82.3% (14/17) of cases with a clear cell lesion, 100% (2/2) of cases with non-clear cell lesions, and 100% (2/2) of benign angiomyolipomas. Conclusion: We firstly evaluated the efficacy of quantitative indocyanine green-based fluorescence as an objective method.

Solid Variant of Serous Cystadenoma of the Pancreas, Cytology Findings

Abstract Introduction Serous cystadenoma of the pancreas is the most common benign neoplasm of the pancreas, tending to have a very good prognosis and treatable by surgical excision. The solid variant of serous cystadenoma of the pancreas is a very rare subtype with only a few cases reported in recent literature, mostly in elderly females. Case History An asymptomatic 85-year-old woman presented with a large pancreatic mass. Endoscopic ultrasound findings were consistent with an ill-defined large isoechoic mass involving almost the entire pancreas, with no significant common bile duct dilation. Fine-needle aspiration was performed. Results The smears showed groups of cells with uniform nuclei, ample cytoplasm, inconspicuous nucleoli, minimal cytologic atypia, and absent mitotic activity, suggesting a benign or low-grade lesion. A solid aggregate of these cells was present in the cell block, which was positive for CK7, inhibin, and PAS. Negative staining for chromogranin, synaptophysin, and B-catenin helped exclude neuroendocrine tumors and solid pseudopapillary neoplasm. Additionally, absent staining for PAX-8, ER, PR, BRST-2, GATA-3, CK20, CDX2, Melan-A, and calretinin helped exclude other metastatic clear cell lesions. Conclusion Diagnosis of solid variant serous cystadenoma of the pancreas can be challenging due to nonspecific clinical symptoms and misdiagnosis as other solid pancreatic tumors. Based on the clinical, radiologic, cytologic, and immunohistochemical features, we favor a diagnosis of solid variant of serous cystadenoma. Recognition of this lesion is important because the vast majority of solid tumors in the pancreas are malignant. The differential diagnosis includes the rare primary clear-cell “sugar” tumor of the pancreas, clear cell carcinoma, clear cell islet cell tumor, and metastatic renal cell carcinoma. Therefore, the diagnosis of solid-type serous cystadenoma of the pancreas is frequently dependent on a series of immunohistochemical and molecular studies.

Gamma-aminobutyric acid decreases macrophages infiltration and suppresses inflammatory responses in renal injury

Abstract The immunomodulatory effects of gamma-aminobutyric acid (GABA) on renal disease were investigated using conditional von Hippel-Lindau gene-knockout C57BL/6 mice (Vhlhdel/del mice), which spontaneously develop fibrosis, inflammation, and hyperplastic clear-cell lesions in the kidneys. Diets containing either GABA rice or pure GABA significantly extended the life span of Vhlhdel/del mice, with decreasing levels of urinary kidney injury molecule (KIM)-1 and renal clear cell formation, which are the typical markers of renal damage. Levels of serum inflammatory markers such as interleukin (IL)-6, renal monocyte chemoattractant protein (MCP)-1, transforming growth factor (TGF)-β, IL-17A, C-C chemokine receptor type 2 (CCR2), and macrophage infiltration were significantly decreased in GABA-fed mice. Further, induction of monocyte migration was significantly suppressed in GABA-treated VHL-silenced HK-2 cells, suggesting that GABA has protective effects against renal injury by disrupting the MCP-1/CCR2 axis and thus macrophage infiltration.

The Proangiogenic Capabilities of Malignant Ascites Generated by Aggressive Ovarian Tumors.

Here we examined whether malignant ascites may determine ovarian tumor angiogenesis, and if so whether ascites generated by highly aggressive serous and undifferentiated cancers are more proangiogenic than those from less aggressive clear cell and endometrioid tumors. Angiogenesis was analyzed according to expression of CD31, CD34, and connexin 43. Proliferation and migration of endothelial cells were tested using fluorescence-based methods. The quantification of angiogenic agents and hypoxia-inducible factor 1α (HIF-1α) was performed using specific immunoassays. Results showed that the expression of CD31 and CD34 in serous and undifferentiated tumors was greater, whereas endothelial expression of connexin 43 was lower than in clear cell and endometrioid lesions. Serous cancers that formed in the presence of ascites displayed increased expression of connexin 43 in vascular smooth muscles as compared with tumors developed in the fluid's absence. Endothelial cells exposed to ascites from serous and undifferentiated tumors proliferated and migrated more vigorously than cells subjected to ascites from clear cell and endometrioid cancers. They also exhibited an increased level of HIF-1α and produced increased amounts of multiple proangiogenic agents. Our results indicate that high vascularization of aggressive ovarian tumors may be associated with profound angiogenic capabilities of ascites generated by these tumors.

Inactivation of the tumor suppressor gene von Hippel-Lindau (VHL) in granulocytes contributes to development of liver hemangiomas in a mouse model.

BackgroundMutations in the tumor suppressor gene von Hippel-Lindau (VHL) underlie a hereditary cancer syndrome—VHL disease—and are also frequently observed in sporadic renal cell carcinoma of the clear cell type (ccRCC). VHL disease is characterized by malignant and benign tumors in a few specific tissues, including ccRCC, hemangioblastoma and pheochromocytoma. The etiology of these tumors remains unresolved.MethodsConditional inactivation of the VHL gene in mouse (Vhlh) was generated to examine the pathophysiological role of the VHL gene function. Specific cell populations were isolated by fluorescence-activated cell sorting (FACS) and bone marrow transplants were performed to identify the Vhlh-inactivated cells responsible for the phenotype.ResultsPreviously we showed that inactivation of Vhlh in a subpopulation of kidney distal tubule cells resulted in hyperplastic clear-cell lesions and severe inflammation and fibrosis. Here, we show that this knockout mouse strain also develops Hif-2α-dependent vascular overgrowth (hemangioma) and extramedullary erythropoiesis in the liver. However, Vhlh inactivation was not detected in the liver parenchyma. We instead demonstrate that in these mice, Vhlh is inactivated in liver granulocytes and that hemangiomas are partially rescued in knockout mice reconstituted with wild-type hematopoietic stem cells, indicating the involvement of bone-marrow-derived leukocyte. Interestingly, bone marrow from knockout mice failed to generate the liver phenotype in wild-type recipients, suggesting that an additional cell type that is not derived from the bone marrow is involved in the development of the hemangioma phenotype.ConclusionThese results support the idea that the development of a full-blown VHL disease phenotype requires inactivation of the VHL gene not only in the tumor proper, but also in the stromal compartment.

Metastasis of renal cell carcinoma to the parathyroid gland 16 years after radical nephrectomy: A case report.

Renal cell carcinoma (RCC) has a high metastatic potential, and most commonly metastasizes via the bloodstream, although lymphatic metastases also occur. RCC is well-known for its propensity to metastasize to unusual sites, and late metastasis, even after a number of years, is common. The occurrence of RCC metastasis to the head and neck region is uncommon, and occurs primarily in the thyroid gland and in patients with widespread dissemination. Involvement of the parathyroid gland in metastatic carcinoma is extremely rare. In the present report, a case of metastasis confined to the parathyroid gland is described, likely with intrathyroidal localization, arising from a RCC that occurred 16 years after nephrectomy. A 66-year-old man was referred to the Department of Surgery of the University Hospital of Pisa (Pisa, Italy) with a preoperative fine-needle aspiration diagnosis of a follicular lesion in the context of nodular goiter of the thyroid gland. The previous medical history of the patient included a right nephrectomy for the treatment of clear cell RCC in February 1997. No other distant metastases were identified as of the latest follow-up in March 2014. At the time of thyroid surgery, the thyroid and parathyroid function tests were normal. The gross appearance of the surgical specimen was a multinodular goiter with a solid nodule measuring 33 mm on the left lobe of the thyroid gland. Microscopic examination revealed a completely encapsulated lesion consisting of clear cells arranged in a solid pattern and intermixed with fragments of parathyroid tissue. Following immunohistochemical examination, the clear cell lesion was negative for thyroid transcription factor-1 and thyroglobulin and strongly positive for epithelial membrane antigen, cluster of differentiation 10 and vimentin. To the best of our knowledge, this is the second case of metastasis to the parathyroid gland from a RCC reported in the literature.

An unusual case of palatal swelling – Hyalinizing clear cell carcinoma: a case report

Hyalinizing clear cell carcinoma is an uncommon malignant salivary gland tumour that appears almost exclusively in the minor salivary glands of the oral cavity.[1, 2] It is an indolent tumour with little metastatic potential, and therefore, it is important to distinguish it from other, more aggressive, clear cell lesions such as metastatic renal cell carcinoma.[3] We present the case of a 48-year-old woman who presented with a 2-year history of a mass on her soft palate. The clinical history, imaging and histopathological features are described and discussed.

Clear Cell Odontogenic Carcinoma (CCOC): Mini-Review of Literature and Case Report of Mandibular Radiolucency in 17-year Girl

A 17-year girl reported with painful right lower posterior teeth. Orthopantomogram showed unilocular radiolucency with scalloped non-sclerotic border at apical area of non-carious right mandibular molars and premolar. A provisional radiological diagnosis of ameloblastoma or odontogenic keratocyst was given. Histopathological examination revealed follicular areas of peripheral palisaded hyperchromatic basaloid cells and central round-polygonal clear cells. A diagnosis of clear cell odontogenic carcinoma (CCOC)-ameloblastomatous variant was made after assessing the provisional diagnoses. A nosological dilemma arose as many authors opined that the terms ‘clear cell ameloblastoma’ and ‘clear cell odontogenic tumor’ should be invalidated and CCOC should be the preferred diagnosis because of the reported aggressive nature of clear cell odontogenic neoplasms. The scientific literature gave variable biological behavior and prognosis with diverse therapeutic approaches leading to therapeutic dilemma in management of the case. The authors have attempted to resolve the diagnostic and therapeutic challenges by presenting the clinical, radiological and histological aspects of the case and discussing the differential diagnoses of clear cell lesions involving the maxillofacial region along with the therapeutic approaches and prognosis of CCOC.

Molecular Characterization of Clear Cell Lesions of Head and Neck.

The salivary glands, oral mucosa and jaws constitute a group of lesions which are heterogeneous in nature and are odontogenic, salivary or metastatic in origin. This group of tumours is termed as Clear Cell Tumours. Fixation artifacts are one of the most important reasons for the cell to appear clear but clearing of cells may also result from cytoplasmic accumulation of water, presence of glycogen within the cell, intermediate filaments, immature zymogen granules, or a paucity of cellular organelles. Clear cell Odontogenic neoplasms predominantly include odontogenic carcinoma, ameloblastoma and calcifying epithelial odontogenic tumour. Clear cell tumours of salivary gland origin are almost invariably malignant in nature but they do include two benign lesions. Very frequently, surgical pathologist encounters clear cells in many malignant neoplasms, the nature and sources of which are undetermined on the basis of conventional histopathology. This review will selectively discuss the clinicopathological features of neoplasms which at times may pose a diagnostic challenge and dilemma due to clear cell changes.

MP69-04 NUTRITIONAL SCREENING IS STRONGLY ASSOCIATED WITH OVERALL SURVIVAL IN PATIENTS TREATED WITH TARGETED AGENTS FOR ADVANCED RENAL CELL CARCINOMA

available at http://www.ncbi.nlm.nih.gov/pubmed/26901011 Editorial Comment: This study examined 137 renal masses without fat. All masses were smaller than 4 cm. Patients were scanned during the noncontrast and nephrographic phases (many also underwent corticomedullary imaging). A total of 117 renal cell carcinomas and 20 benign lesions were included. Of the 117 malignant masses 9 (8%) did not reach the 15 HU enhancement threshold on nephrographic imaging and 14 (12%) did not reach the 20 HU threshold. Clear cell, papillary and chromophobe lesions were identified as the hypoenhancing masses. As we closely scrutinize small renal lesions, enhancement is an important indicator of whether a lesion is solid or cystic. Some solid renal cell carcinomas may be hypoenhancing and overlap in the range with renal cysts that may show some artifactual pseudoenhancement. Radiologists must review the morphology of the small hypoenhancing mass, review prior studies and consult the patient electronic radiology jacket to see if other imaging (ultrasound or magnetic resonance) may assist in differentiating the subtle solid hypoenhancing lesion from a simple cyst, complicated cyst or high attenuation cyst.

204 Nutritional screening is strongly associated with overall survival in patients treated with targeted agents for advanced renal cell carcinoma

available at http://www.ncbi.nlm.nih.gov/pubmed/26901011 Editorial Comment: This study examined 137 renal masses without fat. All masses were smaller than 4 cm. Patients were scanned during the noncontrast and nephrographic phases (many also underwent corticomedullary imaging). A total of 117 renal cell carcinomas and 20 benign lesions were included. Of the 117 malignant masses 9 (8%) did not reach the 15 HU enhancement threshold on nephrographic imaging and 14 (12%) did not reach the 20 HU threshold. Clear cell, papillary and chromophobe lesions were identified as the hypoenhancing masses. As we closely scrutinize small renal lesions, enhancement is an important indicator of whether a lesion is solid or cystic. Some solid renal cell carcinomas may be hypoenhancing and overlap in the range with renal cysts that may show some artifactual pseudoenhancement. Radiologists must review the morphology of the small hypoenhancing mass, review prior studies and consult the patient electronic radiology jacket to see if other imaging (ultrasound or magnetic resonance) may assist in differentiating the subtle solid hypoenhancing lesion from a simple cyst, complicated cyst or high attenuation cyst.