Renal medullary carcinoma: sonographic, computed tomography, magnetic resonance and angiographic findings

Magnetic Resonance Imaging Virtual Biopsy of Common Solid Renal Masses-A Pictorial Review

ABSTRACT

The expanded application of radiologic imaging resulted in an increased incidence of renal masses in the recent decade. Clinically, it is difficult to determine the malignant potential of the renal masses, thus resulting in complex management. Image-guided biopsies are the ongoing standard of care to identify molecular variance but are limited by tumor accessibility and heterogeneity. With the evolving importance of individualized cancer therapies, radiomics has displayed promising results in the identification of tumoral mutation status on routine imaging. This article discusses how magnetic resonance imaging features can guide a radiologist toward identifying renal mass characteristics.

Manifestations of Sickle Cell Disorder at Abdominal and Pelvic Imaging

Sickle cell disorder (SCD) refers to a spectrum of hematologic disorders that cause a characteristic clinical syndrome affecting the entire body. It is the most prevalent monogenetic hemoglobinopathy worldwide, with a wide range of focal and systemic expressions. Hemoglobin gene mutation leads to the formation of abnormal sickle-shaped red blood cells, which cause vascular occlusion and result in tissue and organ ischemia and infarction. Recurrent episodes of acute illness lead to progressive multisystem organ damage and dysfunction. Vaso-occlusion, hemolysis, and infection as a result of functional asplenia are at the core of the disease manifestations. Imaging plays an essential role in the diagnosis and management of SCD-related complications in the abdomen and pelvis. A thorough understanding of the key imaging findings of SCD complications involving hepatobiliary, gastrointestinal, genitourinary, and musculoskeletal systems is crucial to timely recognition and accurate diagnosis. The authors aim to familiarize the radiologist with the SCD spectrum, focusing on the detection and evaluation of manifestations that may appear at imaging of the abdomen and pelvis. The topics the authors address include (a) the pathophysiology of the disease, (b) the placement of SCD among hemoglobinopathies, (c) the clinical presentation of SCD, (d) the role of imaging in the evaluation and diagnosis of patients with SCD who present with abdominal and pelvic manifestations in addition to extraperitoneal manifestations detectable at abdominal or pelvic imaging, (e) imaging features associated with common and uncommon sequelae of SCD in abdominal and pelvic imaging studies, and (f) a brief overview of management and treatment of patients with SCD. Online supplemental material is available for this article. ^©RSNA, 2022.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Imaging features of solid renal masses

The widespread use of abdominal imaging techniques has increased the detection of solid renal masses over the past years. Imaging plays a crucial role in the management and surveillance and in determining which lesions need treatment. The "classical angiomyolipoma" is the only benign solid renal mass that can be characterized with confidence by imaging through the detection of a fat-containing lesion without calcifications. There is a large overlap of imaging features between benign and malignant renal masses that often makes difficult a correct characterization of these lesions. In this review, we discuss the imaging features of the main solid renal masses that may suggest a likely benign diagnosis.

Imaging of Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed.

Renal medullary carcinoma with an ophthalmic metastasis

Renal medullary carcinoma (RMC) is a rare, aggressive primary renal malignancy that classically occurs in adolescent males with sickle cell trait and universally presents with metastatic disease at presentation. We report a case of medullary carcinoma in a young man with likely ophthalmic metastasis. We also review relevant literature available to date. The patient is a 20-year-old African-American male with a past medical history significant to for sickle cell trait who presented to the University Medical Center with cough and the right eye pain for 1 month as well as painless gross hematuria for 1 week. A chest and abdominal computed tomography showed a 7 cm hypodense right renal mass with bilateral hilar adenopathy, and multiple bilateral pulmonary nodules. A renal biopsy was performed and showed RMC. Ophthalmic exam revealed the right retinal hemorrhage concerning for a metastatic lesion. Palliative chemotherapy was offered to the patient, however, he and his family chose to enroll in hospice care considering his poor prognosis. He subsequently passed away 33 days after presentation. To our knowledge, there is only one other case of ophthalmic metastasis in a patient with metastatic RMC. Thus, we present this case to contribute to current literature regarding orbital metastasis in this largely fatal disease.

[Kidney and hemoglobinopathy]

Sickle-cell disease (SCD), one of the most common severe monogenic disorders into the world, is associated with an increased frequency of chronic kidney disease. SCD is caused by a point mutation in the gene encoding β globin gene which leads to the formation of hemoglobin S that polymerises after deoxygenation. HbS polymerisation is associated with erythrocyte rigidity and vaso-occlusive episodes that play a central role into SCD pathogenesis. The spectrum of renal diseases during SCD is broad and includes various renal manifestations which become more apparent with increasing age. Underlying pathophysiological processes involved in sickle cell nephropathy are multifactorial but endothelial dysfunction related to chronic hemolysis is a key factor contributing to renal involvement. Our review focuses on the pathogenesis and on the spectrum of renal manifestations occurring in SCD patients.

Clinical and computed tomography imaging features of renal medullary carcinoma: A report of six cases

Patients with renal medullary carcinoma (RMC) have a poor prognosis, usually due to late diagnosis. Computed tomography (CT) analysis may aid the differentiation between RMC and other types of renal cell carcinoma, in order to establish an accurate early diagnosis. There is a limited number of reports in the literature focusing on clinical and multi-slice CT (MSCT) imaging findings of RMC. Consequently, the present study aimed to characterize the clinical and MSCT imaging features of RMC. For this purpose, the MSCT imaging findings of 6 patients with RMC were retrospectively studied. The patients were subjected to MSCT in order to investigate the characteristics of the tumors, including location, size, density, calcification, cystic or solid appearance, capsule sign, enhancement pattern and presence of retroperitoneal lymph node metastasis. The tumors in the current study presented a mean diameter of 7.48±3.25 cm, and were observed to be solitary and heterogeneous with necrotic components. The majority of the tumors did not contain calcifications (5/6); displayed an ill-defined margin (4/6); were centered in the medulla; extended into the renal pelvis or peripelvic tissues (6/6); and did not exhibit a fibrous capsule. Localized caliectasis was observed in 3 of the 6 cases. The attenuation of the solid region of the RMC on unenhanced CT was equal to that of the renal cortex or medulla (42.3±2.7 vs. 40.7±3.6 and 41.2±3.9 Hounsfield units, respectively; P>0.05) while, on enhanced CT, the enhancement of the tumor was lower than that of the normal renal cortex and medulla during all phases (cortical phase, 52.6±4.8 vs. l99.5±9.7 and 72.7±6.4; medullary phase, 58.6±5.7 vs. 184.6±10.8 and 93.5±7.8; delayed phase, 56.8±6.1 vs. 175.7±8.5 and 96.5±7.9, respectively; P<0.05). In conclusion, RMC tends to be an infiltrative, ill-defined heterogeneous mass with intratumoral necrosis, which arises from the renal medulla, and displays lower enhancement than the renal cortex and medulla during all phases on enhanced CT. Despite its rarity in adults, RMC should be included in a differential diagnosis when CT imaging reveals these features.

Renal medullary carcinoma and sickle cell trait: A systematic review

Sickle cell trait (SCT) carries a small risk of renal medullary carcinoma (RMC). We conducted a systematic literature review and reported new four RMC cases (total N = 217). Eighty eight percent had SCT and 8% had sickle cell disease; 50% were children. Males had 2.4× risk than females. Isolated hematuria or in combination with abdominal or flank pain was the presenting sign in 66% cases. Tumor-related mortality was 95%. Four non-metastatic patients were long-term disease-free survivors. Although risk appears to be very low, individuals with SCT should be informed about the low risk of RMC with the hope of early diagnosis. Hematuria should prompt immediate investigation.

Renal cell carcinoma: histological classification and correlation with imaging findings

Renal cell carcinoma (RCC) is the seventh most common histological type of cancer in the Western world and has shown a sustained increase in its prevalence. The histological classification of RCCs is of utmost importance, considering the significant prognostic and therapeutic implications of its histological subtypes. Imaging methods play an outstanding role in the diagnosis, staging and follow-up of RCC. Clear cell, papillary and chromophobe are the most common histological subtypes of RCC, and their preoperative radiological characterization, either followed or not by confirmatory percutaneous biopsy, may be particularly useful in cases of poor surgical condition, metastatic disease, central mass in a solitary kidney, and in patients eligible for molecular targeted therapy. New strategies recently developed for treating renal cancer, such as cryo and radiofrequency ablation, molecularly targeted therapy and active surveillance also require appropriate preoperative characterization of renal masses. Less common histological types, although sharing nonspecific imaging features, may be suspected on the basis of clinical and epidemiological data. The present study is aimed at reviewing the main clinical and imaging findings of histological RCC subtypes.

Clinical outcome and prognostic factors in renal medullary carcinoma: A pooled analysis from 18 years of medical literature

INTRODUCTION

We describe clinical features and prognostic factors of renal medullary carcinoma (RMC) by performing a pooled analysis of all reported cases since 1995.

METHODS

A systematic search was performed to identify all articles describing patients with medullary renal cancer until February 2013. Survivals were estimated using Kaplan-Meier method with 95% confidence intervals and compared across the groups using the log-rank test. The following factors were evaluated using the Cox proportional hazards model: association of extension of disease at diagnosis, response to therapy, and surgical treatment of primary tumour with overall.

RESULTS

A total 47 articles were selected; these described 165 patients with RMC plus 1 from our centre. The median age was 21 years and 98% of cases had the sickle cell trait. The mean size of the primary tumours was 6.0 cm, with an involvement of loco-regional lymph nodes in 71% of cases. The overall survival at diagnosis was 4.0 months in metastatic patients and 17.0 months in non-metastatic patients. Patients who received platinum-paclitaxel-gemcitabine had longer control of the disease when compared to topoisomerase inhibitors or targeted therapies. The multivariate analysis confirmed that the advanced stage at diagnosis increased the risk of death of about threefold.

CONCLUSION

RMC is a tumour with poorer prognosis; based on these results, platinum-based chemotherapy is the preferred systemic treatment. Even if radical nephrectomy as an up-front strategy did not report a survival benefit, it may be considered to palliate local symptoms and to perform a correct diagnosis.

Characteristics and outcomes of tumors arising from the distal nephron

OBJECTIVE

To compare the characteristics and predictors of cancer-specific survival (CSS) of 2 rare distal nephron tumors--medullary renal cell carcinoma (MRCC) and collecting duct carcinoma (CDC).

METHODS

All cases of histologically verified MRCC and CDC reported to The Surveillance, Epidemiology and End Results (SEER) database between 1995 and 2007 were considered. A number of characteristics were compared by tumor histology. Subset analyses were performed for metastatic patients and those managed surgically. CSS was analyzed using Cox proportional hazard models.

RESULTS

Overall, 21 cases of MRCC and 227 cases of CDC met the criteria for analysis. Patients with MRCC were younger (median 24 vs 63 years, P < .001), more often black (71.4% vs 22.7%, P < .001), metastatic at presentation (71.4% vs 27.8%, P < .001), and less likely to undergo surgery (61.9% vs 85.6%, P = .015) compared with patients with CDC. Tumor size was similar between MRCC and CDC (median 6 vs 5 cm, P = .70). Median survival was 5 months for MRCC and 30 months for CDC (P < .001). In metastatic MRCC and CDC patients, surgery predicted CSS (HR 4.61 and 2.24, both P ≤.05) despite having larger primary tumors than those managed nonsurgically (median 7.5 vs 5.0 cm, P < .01).

CONCLUSION

Patients with MRCC present younger, at a later stage, and are more often black than patients with CDC. The stage migration toward localized kidney cancer is not apparent for these tumors. Although both cancers have a poor prognosis, the clinical and survival characteristics are distinct. Patients selected for cytoreductive surgery have improved survival.

Response to radiation in renal medullary carcinoma

Renal medullary carcinoma (RMC) is a rare and highly aggressive malignancy arising from the renal medulla and found mostly in patients with sickle cell trait. RMC usually presents with widely metastatic disease. We describe a young man diagnosed with metastatic RMC who sustained a complete response to systemic chemotherapy but developed brain metastases with leptomeningeal involvement and subsequently had a partial response to brain irradiation. The use of radiation in the management of RMC is reviewed. Due to the apparent propensity for RMC to spread to the central nervous system, prophylactic treatment such as craniospinal irradiation should be considered along with chemotherapy in patients with metastatic RMC to potentially improve the progression-free interval.

Preliminary experience with epsilon aminocaproic acid for treatment of intractable upper tract hematuria in children with hematological disorders

PURPOSE

Gross, intractable hematuria is rare in children. Although the role of epsilon aminocaproic acid in the management of refractory hematuria is well established in the adult population, few data exist about its use in children for this indication. We present our initial experience with epsilon aminocaproic acid for the treatment of intractable hematuria after more conservative measures failed, and propose an algorithm for administration of epsilon aminocaproic acid in children.

MATERIALS AND METHODS

We reviewed the charts of all patients treated with epsilon aminocaproic acid for intractable gross hematuria at our institution during a period of 36 months. All patients underwent hematological evaluation and any underlying bleeding dyscrasias were addressed. All patients also underwent renal and bladder ultrasound, retrograde pyelogram and ureteroscopy. Demographic information, medical and surgical histories, and epsilon aminocaproic acid dosing and outcomes were recorded.

RESULTS

Three boys and 1 girl 11 to 17 years old were treated with epsilon aminocaproic acid. Three patients had sickle trait (1 with nutcracker phenomenon) and 1 had hemophilia A. Three patients required packed red blood cell transfusions to maintain hematocrit. Three renal angiograms were performed, all of which were nondiagnostic. Duration of hematuria ranged from 1 to 52 weeks before administration of epsilon aminocaproic acid. Endoscopic evaluation demonstrated hematuria localized to 1 ureteral orifice in all 4 patients. All patients received 100 mg/kg epsilon aminocaproic acid orally every 6 hours, which uniformly led to cessation of hematuria.

CONCLUSIONS

Epsilon aminocaproic acid is useful for the management of gross refractory hematuria when more conservative measures fail. Because of its potential side effects, it should be used cautiously.

Renal medullary carcinoma: molecular, pathological and clinical evidence for treatment with topoisomerase-inhibiting therapy

STUDY TYPE

Aetiology (case series) Level of Evidence 4.

OBJECTIVE

To present the molecular rationale and potential clinical benefit of topoisomerase II (TopoII)-inhibiting therapy for renal medullary carcinoma (RMC), a rare but extremely lethal form of kidney cancer that classically afflicts young men with sickle-cell trait. The current therapeutic approach with these aggressive tumours is radical nephrectomy followed by systemic chemotherapy, but the prognosis remains dismal.

MATERIALS AND METHODS

The whole-genome expression was analysed in four RMC tumours. We also report a case of metastatic RMC in which a complete response was achieved for 9 months using a TopoII-inhibiting therapy.

RESULTS

Expanded whole-genome expression analysis showed increases of TopoII in all cases. There was also overall deregulation of DNA remodelling and repair, and an ontological association between RMC and urothelial carcinoma. Using a TopoII-inhibiting agent, there was a complete response for 9 months in a patient with metastatic RMC.

CONCLUSION

This report provides molecular evidence for the rational use of TopoII inhibitors in the treatment of RMC.

Recent developments in the pathology of renal tumors: morphology and molecular characteristics of select entities

CONTEXT

Renal cell carcinoma is a heterogeneous group of tumors with distinct histopathologic features, molecular characteristics, and clinical outcome. These tumors can be sporadic as well as familial or associated with syndromes. The genetic abnormalities underlying these syndromes have been identified and were subsequently found in corresponding sporadic renal tumors.

OBJECTIVE

To review the recent molecular and genetic advancements relating to sporadic and familial renal carcinomas as well as those related to Xp11.2 translocation-associated renal cell carcinoma and renal medullary carcinoma.

DATA SOURCES

Literature review, personal experience, and material from the University of Chicago.

CONCLUSIONS

Molecular genetic diagnostic techniques will continue to introduce new biomarkers that will aid in the differential diagnosis of difficult cases. The identification of specific signaling pathways that are defective in certain renal tumors also makes possible the development of new therapies that selectively target the aberrant activity of the defective proteins.

Computed tomography and magnetic resonance imaging features of lesions of the renal medulla and sinus

The kidneys can harbor a wide variety of lesions, many of which can be visualized by computed tomography and magnetic resonance imaging. In this article, the pertinent renal anatomic relationships as well as the histologic composition and function of the renal medulla and sinus are reviewed. Additionally, computed tomography and magnetic resonance imaging features of renal sinus and medullary lesions in adult patients are presented. This article reviews the salient imaging features of various malignant, benign neoplastic, and nonneoplastic lesions of the sinus and medulla.

Laparoscopic nephrectomy for the management of renal medullary carcinoma in a child

Renal medullary carcinoma is a lethal subtype of renal cancer that afflicts patients with sickle-cell hemoglobinopathies. Here we present the case of a 13-year-old boy with renal medullary carcinoma who is the first, to our knowledge, to be managed using a planned laparoscopic radical nephrectomy.

Renal medullary carcinoma: the Bronx experience

OBJECTIVES

Renal medullary carcinoma (RMC) is a devastating and extremely rare malignancy primarily afflicting young men with sickle cell trait. We present our clinical experience with 9 cases of RMC during a 10-year period and briefly review the published data.

METHODS

A retrospective chart review of 9 cases of RMC during a 10-year period at our institutions was performed. The clinical patient characteristics, presentations, treatments, and outcomes were recorded. The radiographic images and pathologic specimens were reviewed. Applicable studies were selected from a Medline search.

RESULTS

All 9 patients had sickle cell trait, the male/female ratio was 6:3, and the age range was 13 to 31 years. All the patients presented with flank pain, two thirds had hematuria, and 3 of the 9 patients presented with a palpable mass. Eight of the nine tumors were right sided, ranging from 4 to 12 cm in the greatest diameter. Of the 9 patients, 7 underwent radical nephrectomy. One patient was deemed to have unresectable disease by the operating surgeon, and one was given initial chemotherapy after biopsy of a metastatic lesion. The neoadjuvant therapies varied. Overall survival ranged from 4 to 16 months, with 2 patients still living at the last follow-up visit.

CONCLUSIONS

Our urban setting likely explains our relatively large experience with this rare and extremely aggressive tumor. An early diagnosis is critical, and a high index of suspicion should be given to any individual with sickle cell trait and new-onset hematuria, especially in the setting of a right-sided mass. Prospective trials are needed for chemotherapy/immunotherapy, because surgical intervention alone is inadequate.

Renal medullary carcinoma: report of seven cases from Brazil

We report seven cases of renal medullary carcinoma collected from several institutions in Brazil. In spite of a relatively high incidence of sickle cell trait in Brazil, this is a rare tumor. All patients were males between the ages of 8 and 69 years (mean 22 years). From the collected information, the most frequent presenting symptoms were gross hematuria and flank or abdominal pain. The duration of symptoms ranged from 1 week to 5 months. Most of the tumors were poorly circumscribed arising centrally in the renal medulla. Size ranged from 4 to 12 cm (mean 7 cm) and hemorrhage and necrosis were common findings. All seven cases described showed sickled red blood cells in the tissue and six patients were confirmed to have sickle cell trait. All cases disclosed the characteristic reticular pattern consisting of tumor cell aggregates forming spaces of varied size, reminiscent of yolk sac testicular tumors of reticular type. Other findings included microcystic, tubular, trabecular, solid and adenoid-cystic patterns, rhabdoid-like cells and stromal desmoplasia. A peculiar feature was suppurative necrosis typically resembling microabscesses within epithelial aggregates. The medullary carcinoma of the 69-year-old patient was associated with a conventional clear cell carcinoma. To our knowledge, this association has not been previously reported and the patient is the oldest in the literature. The survival after diagnosis or admission ranged from 4 days to 9 months. The 8-year-old African-Brazilian patient with a circumscribed mass is alive and free of recurrence 8 years after diagnosis. This case raises the question whether a periodic search for renal medullary carcinoma in young patients who have known abnormalities of the hemoglobin gene and hematuria could result in an early diagnosis and a better survival.

Renal medullary carcinoma: unsuspected diagnosis at stone protocol CT

Renal medullary carcinoma (RMC) is an aggressive neoplasm occurring almost exclusively in adolescents and young adults with sickle cell (SC) hemoglobinopathies, usually sickle cell trait (SCT) or hemoglobin SC disease. The most common presentations are hematuria and flank or abdominal pain. It is a highly malignant tumor, and responses to chemotherapy are rare and transient resulting in a dismal prognosis. A high level of suspicion is necessary when evaluating at risk patients presenting with hematuria or flank pain, as currently it appears that only early diagnosis could potentially alter the outcome of this disease. We report a case of RMC in a young male patient with SCT, who presented to the emergency department with low back pain and microscopic hematuria, clinically mimicking acute obstructing urolithiasis. Our case emphasizes the need to consider alternate diagnoses when evaluating computed tomography scans for acute flank pain.

Renal Medullary Carcinoma: CT and MRI Features

OBJECTIVE

We review the cross-sectional imaging findings of six cases of pathologically proven renal medullary carcinoma in patients with sickle cell trait. MRI findings were available in three of the patients. To our knowledge, only one previous report has addressed MRI features of this rare disease.

CONCLUSION

In young patients with sickle cell trait, an infiltrative renal mass with associated retroperitoneal adenopathy and caliectasis are characteristic findings of renal medullary carcinoma on CT and MRI.

Renal medullary carcinoma and ABL gene amplification

PURPOSE

We characterized the clinical course of renal medullary carcinoma (RMC) and performed an expanded analysis of BCR-ABL.

MATERIALS AND METHODS

The literature was searched for all reports of RMC. New cases at Northwestern University are described and relevant clinical information was abstracted. BCR and ABL genes, and ABL protein were evaluated by fluorescence in situ hybridization and immunohistochemical analysis, respectively.

RESULTS

A total of 95 cases were identified. Mean age at diagnosis was 19 years, the male-to-female ratio was 1.9:1.0, 90% of all patients were black, 98% had an abnormality in a least 1 hemoglobin gene (ie sickle cell trait, SC disease or sickle cell disease) and mean survival was 19 weeks. Two patients (3%) without metastasis were long-term survivors. The response to chemotherapy was poor. One patient treated with thalidomide survived for 52 weeks. The ABL gene was amplified a mean +/- SEM of 1.9 +/- 0.1-fold in all 3 cases evaluated, while ABL protein was increased in 2 of 3 evaluated. No evidence of BCR-ABL translocation was detected.

CONCLUSIONS

RMC is typically seen in young individuals with the sickle cell trait. It is diagnosed when metastatic, is not responsive to systemic therapy and rapidly causes death. Because cure appears possible with early diagnosis, increased awareness of the disease could make an impact. The use of thalidomide or newer anti-angiogenesis agents should be considered for advanced disease. The role of ABL amplification with respect to etiology and as a therapeutic target should be investigated further.

Renal Medullary Carcinoma Metastatic to the Orbit: A Clinicopathologic Report

A 39-year-old black man with sickle cell trait presented with a rapidly progressive, painful proptosis of the left eye. A computed tomographic scan was interpreted as revealing a cavernous hemangioma. Medial orbitotomy revealed a hard, gray mass supranasal to the optic nerve and invading the medial rectus muscle. Intraoperative frozen section specimens were read initially by the pathologist as metastatic adenocarcinoma. On gross examination, the conspicuous hemorrhage, necrosis, and bright yellow color characteristic of renal cell carcinoma were not present. Final pathologic analysis of the orbital lesion revealed metastatic renal medullary cell carcinoma. The primary lesion was located in the right kidney. Renal medullary carcinoma is a rare tumor, often affecting young individuals with sickle cell trait or disease. We report the first confirmed case of renal medullary carcinoma metastatic to the orbit with orbital symptoms preceding the diagnosis of the primary tumor.

Renal Medullary Carcinoma

Renal medullary carcinoma is a recently recognized epithelial malignant tumor arising in the renal parenchyma. The tumor is almost exclusive to young black patients with the sickle cell trait. Most patients present with metastatic disease and have a poor prognosis. An Hispanic woman with renal medullary carcinoma who initially responded to chemotherapy with methotrexate, vinblastine, doxorubicin, and cisplatin and survived for 12 months is presented. The clinical, histologic, and radiologic features of this tumor are described, and chemotherapeutic regimens used in this disease are detailed. Treatment modalities have proved largely unsuccessful in the setting of advanced disease. Given the shared demographic, clinical, and radiographic features of these patients, awareness and early diagnosis may prove essential in improving survival.

Renal medullary carcinoma: a report of 2 cases and review of the literature

Renal medullary carcinoma is a recently described aggressive neoplasm of the kidney. With the exception of 2 patients, all other reported cases have been associated with sickle cell hemoglobinopathies, mainly sickle cell trait and hemoglobin SC disease. Renal medullary carcinoma is a highly malignant tumor with evidence of angiolymphatic and distant metastasis at the time of diagnosis. No specific genetic abnormality has been identified in this neoplasm despite its close association with a genetic disease. We describe 2 cases of renal medullary carcinoma, one associated with hemoglobin SC disease, and the other with what we believe to be the first reported case associated with sickle cell disease.

Renal complications of sickle cell disease: managing for optimal outcomes

A broad spectrum of renal changes is observed in patients with sickle cell anemia, and ideal therapeutic measures for the management of these alterations are still being studied. Affected patients have deficient urinary concentration and potassium excretion. Perhaps owing to a compensatory mechanism, the proximal tubules are in a condition of "hyperfunction", with increased sodium and phosphorus reabsorption and greater creatinine and uric acid secretion. Mild tubular acidosis may be present. No treatment has been reported for these tubular changes, except for care in the maintenance of hydration. The use of anti-inflammatory drugs is being studied in order to inhibit the prostaglandins involved in the process. Increased renal blood flow, glomerular filtration rate, and filtration fraction are frequent findings. Hematuria commonly occurs as a consequence of red blood cell sickling in the renal medulla, papillary necrosis, or even renal medullary carcinoma. Measures such as increased fluid ingestion, urine alkalinization and, if necessary, administration of epsilon-aminocaproic acid and certain invasive procedures have been proposed to treat hematuria. Nephropathy in patients with sickle cell anemia can be manifested by proteinuria and, more rarely, nephrotic syndrome. Drugs such as prednisone and cyclophosphamide are ineffective for the treatment of patients with nephrotic syndrome. Angiotensin converting enzyme inhibitors decrease proteinuria, but their long-term effect in preventing the progression of glomerular disease has not been established. Chronic renal failure, although infrequent, may be one of the manifestations of this disease. Hemodialysis and transplantation are satisfactory therapeutic options for patients with end-stage renal disease.