Congenital mesoblastic nephroma
   HOME

TheInfoList



OR:

Congenital mesoblastic nephroma, while rare, is the most common
kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
neoplasm A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
diagnosed in the first three months of life and accounts for 3-5% of all childhood renal neoplasms. This neoplasm is generally non-aggressive and amenable to surgical removal. However, a readily identifiable subset of these kidney tumors has a more malignant potential and is capable of causing life-threatening
metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then ...
. Congenital mesoblastic nephroma was first named as such in 1967 but was recognized decades before this as fetal renal hamartoma or leiomyomatous renal hamartoma.


Presentation

Congenital mesoblastic nephroma typically (76% of cases) presents as an abdominal mass which is detected prenatally (16% of cases) by
ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
or by clinical inspection (84% of cases) either at birth or by 3.8 years of age (median age ~1 month). The neoplasm shows a slight male preference. Concurrent findings include hypertension (19% of cases), polyhydramnios (i.e. excess of amniotic fluid in the
amniotic sac The amniotic sac, also called the bag of waters or the membranes, is the sac in which the embryo and later fetus develops in amniotes. It is a thin but tough transparent pair of membranes that hold a developing embryo (and later fetus) until s ...
) (15%),
hematuria Hematuria or haematuria is defined as the presence of blood or red blood cells in the urine. “Gross hematuria” occurs when urine appears red, brown, or tea-colored due to the presence of blood. Hematuria may also be subtle and only detectable w ...
(11%), hypercalcemia (4%), and elevated serum levels of the kidney-secreted, hypertension-inducing enzyme,
renin Renin (etymology and pronunciation), also known as an angiotensinogenase, is an aspartic protease protein and enzyme secreted by the kidneys that participates in the body's renin–angiotensin–aldosterone system (RAAS)—also known as the r ...
(1%). Congenital anomalies have been reported in 11 patients: 6 with genitourinary anomalies, 2 with gastrointestinal anomalies, 1 with
hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary inc ...
, and 1 with the Beckwith–Wiedemann syndrome. The vast majority of patients present with localized (i.e. non-
metastatic Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
) disease. Most patients' disease is classified at presentation as stage I or II (i.e. localized), few patients present with stage III (i.e. locally advanced/infiltrating), and virtually no patients present with stage IV (
metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then ...
present or V (i.e. tumors in both kidneys) disease (see staging of renal cancer).


Tumor pathology

Congenital Mesoblastic nephroma is a malignant tumorous growth of the kidney's mesenchyme (i.e. connective tissue cells).
Histologic Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...
examination of these tumors provides critical information on their prognoses. This examination divides congenital mesoblastic nephroma into three types: * 1) The classic type occurs in ~39% of patients. Its tissues show interlaced spindle-shaped smooth muscle cells evidencing low
mitotic In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintai ...
activity with no evidence of tumor encapsulation; and infiltration into and entrapment of normal kidney tissue. * 2) The cellular type occurs in ~42% of patients. Its tissues show densely packed fibrosarcoma-like cells evidencing high rates of mitosis, less infiltration of normal kidney tissue, and multiple areas of hemorrhage and
cysts A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...
. * 3) The mixed type occurs in ~19% of patients. It shows a mixture of the classic and cellular types in different areas of the neoplasm.


Genetics

A study conducted in 1998 found that congenital mesoblastic nephroma tissues taken from some patients contained an acquired mutation, the ''ETV6-NTRK3''
fusion gene A fusion gene is a hybrid gene formed from two previously independent genes. It can occur as a result of translocation, interstitial deletion, or chromosomal inversion. Fusion genes have been found to be prevalent in all main types of human neopla ...
. This gene results from a translocation of genetic material from the ''
ETV6 ETV6 (i.e. translocation-Ets-leukemia virus) protein is a transcription factor that in humans is encoded by the ''ETV6'' (previously known as ''TEL'') gene. The ETV6 protein regulates the development and growth of diverse cell types, particularly ...
'' gene located on the short arm (designated p) of chromosome 12 at position p13.2 (i.e. 12p13.2) to the ''
NTRK3 Tropomyosin receptor kinase C (TrkC), also known as NT-3 growth factor receptor, neurotrophic tyrosine kinase receptor type 3, or TrkC tyrosine kinase is a protein that in humans is encoded by the ''NTRK3'' gene. TrkC is the high affinity catalyt ...
'' gene located on the long arm (designated q) of chromosome 15 at position q25.3 (i.e. 15q25.3). This ''ETV6-NTRK3'' gene fusion is notated as t(12;15)(p13;q25) and consists of the 5' end of ''ETV6'' fused to the
3' end Directionality, in molecular biology and biochemistry, is the end-to-end chemical orientation of a single strand of nucleic acid. In a single strand of DNA or RNA, the chemical convention of naming carbon atoms in the nucleotide pentose-sugar-r ...
of ''NTRK3''. In consequence, the
chimeric protein Fusion proteins or chimeric (kī-ˈmir-ik) proteins (literally, made of parts from different sources) are proteins created through the joining of two or more genes that originally coded for separate proteins. Translation of this '' fusion gene'' ...
product of this gene lacks ETV6 protein's transcription factor activity while having NTRK3 protein's tyrosine kinase in an unregulated and continuously active form. Either event can drive the malignant growth of cells but in most cases the chimeric protein's tyrosine kinase activity appears responsible for doing so. Based on a limited number of genetic studies (a total of 65 patients), the ''ETY6-NTRK3'' fusion gene appears to occur in most cases of the cellular and some cases of the mixed but no cases of the classical types of congenital mesolastic nephroma. However, a more recent study of 19 patients detected the fused gene in all 8 cases of cellular, 5 of 6 cases of mixed, and 0 of 5 cases of classic mesoblastic nephroma. This suggests that expression of this fused gene may be more common in cellar and mixed mesoblastic nephroma than previously appreciated.
Trisomy A trisomy is a type of polysomy in which there are three instances of a particular chromosome, instead of the normal two. A trisomy is a type of aneuploidy (an abnormal number of chromosomes). Description and causes Most organisms that reprodu ...
, i.e. pathological presence of an extra chromosome, also occurs in these neoplasms. Trisomy of chromosome 11 (e.g. trisomy 11) appears to be the most commonly found trisomy in this disease, being detected in 7 of 13 genetically studied cases. Individual
case report In medicine, a case report is a detailed report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient. Case reports may contain a demographic profile of the patient, but usually describe an unusual or novel occurrenc ...
s have also found trisomy 8 (9 cases), 17 (4 cases), 20 (4 cases), 7 (3 cases), 10 (3 cases), 18 (2 cases), 2 (2 cases), and 9 (2 cases) associated with the disease. The contribution of these trisomies to the development of mesoblastic nephroma is unclear.


Diagnosis

Diagnosis of mesoblastic nephroma and its particular type (i.e. classic, mixed, or cellular) is made by histological examination of tissues obtained at surgery. Besides its histological appearance, various features of this disease aid in making a differential diagnosis that distinguish it from the following childhood neoplasms: *
Wilms tumor Wilms' tumor or Wilms tumor, also known as nephroblastoma, is a cancer of the kidneys that typically occurs in children, rarely in adults.; and occurs most commonly as a renal tumor in child patients. It is named after Max Wilms, the German ...
is the most common childhood kidney neoplasm, representing some 85% of cases. Unlike mesoblastic nephroma, <2% of Wilms tumor patients present at under 3 months of age and most present in patients of >3 years of age. Bilateral kidney tumors, concurrent birth defects, and/or metastatic disease at presentation favor a diagnosis of Wilms tumor. * congenital infantile sarcoma is a rare aggressive
sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sar ...
typically presenting in the lower extremities, head, or neck of infants during their first year of life. The histology, association with the ''ETV6-NRTK3'' fusion gene along with certain chromosome trisomies, and the distribution of markers for cell type (i.e. cyclin D1 and
Beta-catenin Catenin beta-1, also known as beta-catenin (β-catenin), is a protein that in humans is encoded by the ''CTNNB1'' gene. Beta-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcrip ...
) within this tumor are the same as those found in cellular mesoblastic nephroma. Mesoblastic nephroma and congenital infantile sarcoma appear to be the same diseases with mesoblastic lymphoma originating in the kidney and congenital infantile sarcoma originating in non-renal tissues. * Rhabdoid tumor, which accounts for 5-10% of childhood kidney neoplasms, occurs predominantly in children from 1 to 2 years of age. Unlike mesoblastic nephroma, rhabdoid tumors may present with tumors in other tissues including in ~13% of cases, the brain. Rhabdoid tumors have a distinctive histology and abnormalities (i.e.
loss of heterozygosity Loss of heterozygosity (LOH) is a type of genetic abnormality in diploid organisms in which one copy of an entire gene and its surrounding chromosomal region are lost. Since diploid cells have two copies of their genes, one from each parent, a sing ...
, single nucleotide polymorphism, and deletions) in chromosome 22. * Clear cell sarcoma of the kidney, which is responsible for 5-10% of childhood pediatric tumors, occurs predominantly in children from 2 to 3 years of age. Unlike mesoblastic nephroma, clear cell sarcoma of the kidney presents with metastasis, particularly to bone, in 5-6% of cases; it histology is diverse and has been mistaken for mesoblastic nephroma. One chromosomal translocations t,(10;17)(q22;p13), has been repeatedly reported to be associated with clear cell sarcoma of the kidney. * Infantile myofibromatosis is a fibrous tumor of infancy and childhood most commonly presenting during the first 2 years of life as a single subcutaneous nodule of the head and neck region or less commonly as multiple lesions of skin, muscle, bone, and in ~33% of these latter cases, visceral organs. All of these lesions have an excellent prognosis and can regress spontaneously except for those in which there is visceral involvement where the prognosis is poor. While infantile myofibromatosis and classic mesoblastic nephroma have been suggested to be the same diseases because of their very similar histology, studies on the distribution of cell-type markers (i.e. cyclin D1 and
Beta-catenin Catenin beta-1, also known as beta-catenin (β-catenin), is a protein that in humans is encoded by the ''CTNNB1'' gene. Beta-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcrip ...
) indicate that they have different cellular origins.


Treatment

Based on a survey of >800, surgical removal of the entire involved kidney plus the peri-renal fat appeared curative for the majority of all types of mesoblastic nephroma; the patient overall survival rate was 94%. Of the 4% of non-survivors, half were due to surgical or chemotherapeutic treatments. Another 4% of these patients suffered relapses, primarily in the local area of surgery rare cases of relapse due to lung or bone metastasis.. About 60% of these recurrent cases had a complete remission following further treatment. Recurrent disease was treated with a second surgery, radiation, and/or chemotherapy that often
vincristine Vincristine, also known as leurocristine and marketed under the brand name Oncovin among others, is a chemotherapy medication used to treat a number of types of cancer. This includes acute lymphocytic leukemia, acute myeloid leukemia, Hodgkin's ...
and
actinomycin Dactinomycin, also known as actinomycin D, is a chemotherapy medication used to treat a number of types of cancer. This includes Wilms tumor, rhabdomyosarcoma, Ewing's sarcoma, trophoblastic neoplasm, testicular cancer, and certain types of ovari ...
treatment. Removal of the entire afflicted kidney plus the peri-renal fat appears critical to avoiding local recurrences. In general, patients who were older than 3 months of age at diagnosis or had the cellular form of the disease, stage III disease, or involvement of renal lymph nodes had a higher recurrence rate. Among patients with these risk factors, only those with lymph node involvement are recommended for further therapy. It has been suggested that mesoblastic nephroma patients with lymph node involvement or recurrent disease might benefit by adding the
ALK inhibitor ALK inhibitors are anti-cancer drugs that act on tumours with variations of anaplastic lymphoma kinase (ALK) such as an EML4- ALK translocation. They fall under the category of tyrosine kinase inhibitors, which work by inhibiting proteins involv ...
,
crizotinib Crizotinib, sold under the brand name Xalkori among others, is an anti-cancer medication used for the treatment of non-small cell lung carcinoma (NSCLC). It acts as an ALK ( anaplastic lymphoma kinase) and ROS1 ( c-ros oncogene 1) inhibitor. ...
, or a
tyrosine kinase A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger cla ...
inhibitor, either
larotrectinib Larotrectinib, sold under the brand name Vitrakvi, is a medication for the treatment of cancer. It is an inhibitor of tropomyosin kinase receptors TrkA, TrkB, and TrkC. It was discovered by Array BioPharma and licensed to Loxo Oncology in 201 ...
or
entrectinib Entrectinib, sold under the brand name Rozlytrek, is an anti-cancer medication used to treat ROS1-positive non-small cell lung cancer and NTRK fusion-positive solid tumors. It is a selective tyrosine kinase inhibitor (TKI), of the tropomyosin r ...
, to surgical, radiation, and/or
chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
treatment regimens. These drugs inhibit NTRK3's tyrosine kinase activity. Crizotinib has proven useful in treating certain cases of acute lymphoblastic leukemia that are associated with the ''ETV6-NTRK3'' fusion gene while larotrectinib and entrectinib have been useful in treating various cancers (e.g. a metastatic
sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sar ...
,
papillary thyroid cancer Papillary thyroid cancer or papillary thyroid carcinoma is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases.Chapter 20 in: 8th edition. It occurs more frequently in women and presents in th ...
,
non-small-cell lung carcinoma Non-small-cell lung cancer (NSCLC) is any type of epithelial lung cancer other than small-cell lung carcinoma (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitive to chemotherapy, compared to s ...
,
gastrointestinal stromal tumor Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavior ...
, mammary analog secretory carcinoma, and colorectal cancer) that are driven by mutated, overly active tyrosine kinases. Relevant to this issue, a 16-month-old girl with infantile fibrosarcoma harboring the ''ETV6–NTRK3'' fusion gene was successfully treated with larotrectinib. The success of these drugs, however, will likely depend on the relative malignancy-promoting roles of ETV6-NTRK3 protein's tyrosine kinase activity, the lose of ETV6-related transcription activity accompanying formation of ETV6-NTRK3 protein, and the various trisomy chromosomes that populate mesoblastic nephroma.


References


External links


Congenital mesoblastic nephroma
entry in the public domain NCI Dictionary of Cancer Terms {{Urologic neoplasia Urological neoplasia