The Child With An Abdominal Mass

Transcription

1 The Child With An Abdominal Mass Today we are going to talk about pediatric surgery, the abdominal masses in children. Firstly we have to take a full history and make a general, local and rectal examination which is very important. Any mass in any child can be noticed by the doctor in general routine examination or by his mother. - There is some important information that must be identified for any mass in any child:- 1- The Site, Characteristics, the Size, Consistency, and the Mobility. (Mobility when it is mobile we usually think that the lesion is not badly advanced and usually surgery is likely not to be difficult, while fixed masses usually difficult to treat surgically as a basic principle). So, knowing the mobility (with all the previous points) will help us and will give us an idea about the probable 2- Organ Of Origin (i.e.:- is it kidney, suprarenal glands, any pelvic organ etc). knowing the 3- Age, How old is the child?, is very important because neonate and infants with abdominal masses usually the mass of congenital origin while in older age children the mass can be due to acquired causes. Knowing the most likely 4- Pathological Process arising in the organ affected is mostly related to the 5- Length of the History (long or short) a history of a mass for a few days (acute) duration is different from a mass being there for a few months (chronic),where the 6- Symptoms will differ, usually acute cases are painful while the chronic cases might be milder or without symptoms. Abdominal masses can be congenital or acquired, and these masses can be benign or malignant.

2 Q: - What are the most common malignant abdominal masses of the pediatric age group? 1- Neuroblastoma: * It is originated from the suprarenal glands (commonly). * It can be extra-adrenal (very very rare). * The most common malignant mass from the suprarenal gland. * The most common malignant tumor in the pediatric age group. * It is a malignant round cell tumor of the suprarenal gland. 2- Wilm's tumor (Nephroblastoma): * It is originated from the kidneys (kidney parenchyma or tumor of any other renal origin). * It is the most common kidney malignant tumor in the pediatric age group. *It is the second common malignant tumor in the abdomen in the pediatric age group. The doctor advised: if you memorize the organ of origin of these masses it will be easy to list all the different types. The most common kidney tumor in adults is Renal Cell Carcinoma while the most common kidney tumor in children is Nephroblastoma. the Doctor will discuss both of these tumors (1+2) in details later. Less commonly: 3- Malignant lymphoma: * It is originated from the bowls (small intestine "commonly", large intestine "less common") * It is of Non-Hodgkin type. * They may be present as an abdominal mass or other features of intestinal problem like intestinal obstruction, perforation of malignant lymphoma as acute abdomen,.. and so on.

3 4- Lymphosarcoma: * It is type of sarcoma that means malignancy of the connective tissue (while carcinoma is the malignancy of the epithelial tissue). * Sarcoma is more common in children as malignancy. * It is also might be presented as abdominal mass. * It is less common than the other tumors ( a rare tumor) but it is one of the very badly malignant sarcoma. 5- Hepatoblastoma: * The commonest liver malignancy in the pediatric age group (while the commonest liver tumor in adults is the secondary metastasis from the other drainage site in the abdomen) * It is a primary liver malignancy. 6- Other suprarenal tumors: * Rarely suprarenal gland may give rise to malignant tumors of Non- Neuroblastoma tumors type, which may present as abdominal mass. 7- Others:- * Including rhabdomyosarcoma, which usually in children is originated from the pelvic organs especially the urinary bladder, which may be presented as a pelvic mass in children. * Other malignancies to be presented as abdominal mass alone are very rare. SUMMARY:- So considering the primary organ giving the origin:- # The kidneys give rise to Wilm's tumor" commonest". #The suprarenal gland either Neuroblastoma or less commonly non- Neuroblastoma.

4 # The intestine might give rise to lymphoma. # The live might give rise to hepatoblastoma. # The lymphosarcoma can be originated from the rest of the tissues especially the lymph nodes and the lymphatic tissue in the abdomen. Now, what about benign abdominal masses? Here we are mentioning mass rather than tumor because it is a palpable lesion. 1- Hydronephrotic kidney or kidney of a distended pelvicalyical system due to the impairment of the urine outflow can be presented as loin mass, so here it is a benign mass rather than a malignant tumor. The commonest cause of the congenital hydronephrosis in the presence of obstruction between the junction of the pelvis and the ureter and it is called congenital peliviuretric junction obstruction. It is very common presented as a loin mass in children, also but less commonly polycystic or multicystic kidney will give a mass in the loin as well. 2- Mesenteric cyst and duplication of the intestine where it is of a cystic type might also presented as abdominal mass, the location of this mass is usually in the center of the abdomen (not in the loin). The mesenteric mass as tumor (or more commonly mesenteric cyst) is either symptomatic (when it is complicated) or asymptomatic (not complicated that means painless detectable mass). 3-The intestinal duplication, which is a congenital condition, when the intestine duplicate developmentary.

5 The duplication generally is one of two types:- 1-Cyst type, the duplication forms a cyst attached to the mesentery of the normal intestine. 2- Tubular type, where we have a loop of the intestine joining another loop of duplication. When it is cystic duplication it is presented as abdominal mass, once it is complicated it will present as acute abdominal problem. 4-hydatid cyst: In the areas of the world endemic with hydatid disease, older children (4,5 year old) might be presented with abdominal mass because of the hydatid cyst whether originated from the liver or from any other organ. EXAMPLE: A toddler child (1-3 year old) with an abdominal mass, which could be detected by a routine clinical examination of the abdomen or by the child mother, has three possible diagnosis (according to the most common masses at this age group): 1- Two of them are originated from the kidney: Wilm's tumor "malignant", hydronephrosis "benign". 2- One originated from the suprarenal gland which is abdominal neuroblastoma. (If it is not one of these three it could be any one of the other benign or malignant tumors which are previously mentioned). So if we have a child of this age group with a mass which is palpable with no tenderness usually, firm in consistency think about the previously mentioned lesions. When having such an abdominal mass, what are the investigations we need to perform to reach a definite diagnosis? 1- Once you feel a mass in the abdomen, DON'T REPEAT PALPATING AND SQUEZING THE MASS, just do minimal palpation because

6 palpating a malignant tumor especially Neuroblastoma might enhance metastasis. So once you palpate a mass and you suspect that it is a malignant tumor, restrict your palpation to the minimum. 2- Take an X-RAY: Plain X-ray to the abdomen to see????? to the area of the lesion, we might see calcification on the area of the mass which usually with Neuroblastoma. Then we might proceed to renal angiogram or intravenous urogram (I.V.U). We do all of these investigations to study the tumor and to make sure that the other kidney is normal because most of the tumors which are originating from the kidney, when they are malignant, are treated by nephroctomy so we need the other kidney to be functioning normally, if we have agenesis on the other kidney (absence of a kidney) or the other kidney is not functioning normally, all our line of treatment will change. 3- Ultra-Sound (US), CT scan, and MRI: US to see whether the tumor is solid or cystic (one or multicystic) so US will help to give us more details about the tumor and its relations to other structures. 4- Blood and Urine examination: (especially when we suspect Neuroblastoma)Because metabolites of the tumor can be detected in the blood and in the urine samples and this might help us to reach our diagnosis. 5- Bone Marrow Aspiration or biopsy: In the case we suspect a malignancies especially Neuroblastoma, which metastasis early to the bone marrow and if we suspect it and the bone marrow proved that there are malignant cells of round cell type in the BM aspirate it will indicate(1) that our diagnosis is definite.

7 (2) It is an advanced stage by BM metastasis. So the line of treatment will be planed according to these results. 6- When the tumor is huge and very big and it is not mobile and infiltrative, giving an impression of an advanced lesion and we don t think that surgery is applicable, we might reach the diagnosis after a cytological examination of an aspiration ( Fine Needle Aspiration Cytology "FNAC"), here we have to be careful not to rupture the tumor QUESTION by a colleague:- Are these procedures only applied to children??????????? ANS.: NO. Now, I have mentioned the two groups of masses which are the benign and the malignant, and I will concentrate on two tumors both of them are malignant and both of them are common in the pediatric age group which are the Neuroblastoma and Wilm's tumor. Neuroblastoma - It is one of the most malignant round cell tumors. - It is originated from the suprarenal gland and it is believed that it is a raised from the fetal neural crest. - The age of presentation is usually around 2 years old. - On examination:- There is a mass located on the loin usually firm in consistency (not soft "firm to hard consistency"), not very well defined eages, diffuse of limited mobility ( maybe fixed), and either extend to the midline or cross it. Wilm's tumor usually does not cross the midline, while Neuroblastoma does. Usually the child has history of fever and weight loss. So, if u have a child 2 to 2.5 yr old presenting with abdominal mass with or without symptoms located in the loin, having the character of malignancy we think of Neuroblastoma, while older children (3-4 yr old) having a mass in the loin usually we think about Wilm's tumor or Nephroblastoma.

8 you can see this is a child having a loin mass and we put (DO NOT PALPATE) for the student because we afraid of squeezing and rupturing the tumor. This is the appearance of the tumor of the suprarenal gland malignancy of neuroblastoma, striching the loop of the intestine because it is a retroperitoneal organ This IVU and as we can see it displacing the pelvicalysis system down, the kidney should be here (guess where????). Tumor in the suprarenal gland will displace the kidney rether than distort the collecting system in contradistiction to Wilm's tumor. Long Bone Metastasis See next page

9 It is very matignant tumor and it is metastasis early, so the question here is: WHERE DOSE IT METASTASIS? 1- Bone marrow: it is very common in Neuroblastoma, so once we suspect it, we do bone marrow aspiration and if it comes positive for malignant cells this means *It is Neuroblastoma. *It is in an advanced stage. 2- Cortex of the long bones, skull, spine. 3- Orbit (A characteristic feature, which will give us an orbital or ocular spread very important). Rarely other childhood tumors will metastasis to the orbit but in Neuroblastoma it is characteristic. 4- Lymph node metastasis in the abdomen. 5- Liver (especially the right Neuroblastoma). 6- Periorbital metastasis (a characteristic feature, once we see a child with this eyes (look at the picture below) it is metastatic Neuroblastoma, it is called raccoon like appearance of metastatic Neuroblastoma. So when we suspect a Neuroblastoma in a child with abdominal mass, we usually investigate for all these sites of metastasis, and if we see the eyes of the child like this one the diagnosis is more or less established.

10 What is the outcome of Neuroblastoma? It is badly malignant tumor, and its prognosis is usually poor especially when there is distant metastasis (65-75%) but minority of the tumors (about 3% or less) might regress or cure spontaneously, no one knows how exactly!!!! But some people think because of the maturation of the malignant cells into benign cells, so there is a possibility to cure but its % is low. Most of the cases of Neuroblastoma, when we made our diagnosis the metastasis is already established and the cells have been spread to the areas we have mentioned (pervious page) so in 60-75% of the cases, that is why the prognosis is usually poor. Another outcome (which is also rare, less than 1%of the cases) is the maturation into benign Ganglioneuroma. Although it is badly malignant one but it is sensitive to radiotherapy and usually favorably respond to cytotoxic drugs, if these modalities of treatment are ablied in the proper time. When the clinical evidence suggests that the mass is Neuroblastoma, (abdominal or loin mass hard in consistency crossing the midline), the investigations required are:- 1) First to do in BONE MARROW BIOPSY (it is positive in 2\3 of the cases). 2) Do SKELETAL SURVEY. 3) Do BIOPSY of the suspicious sites of metastasis (i.e.: lymph node biopsy for example to see if they are involved). 4) Examine URINE AND BLOOD for the metabolites of Neuroblastoma (i.e.: CATECHOLAMINE metabolites (adrenalin and noradrenalin) because the tumor cells might produce they without sense of their production, VMA, MHMA)" after a collection of urine of 24 hours ", this is a very strong evidence of the diagnosis even before the metastasis.

11 5) Chest X-RAY, to localize and have an idea about the extent of the lesion. Not mentioned by the Dr.: 6) I.V.U, Ultrasound, MRI. 7) Fine needle aspiration cytology? Biopsy. What is the treatment? If the diagnosis is established early, the treatment is surgical excision (we will be very happy if we remove the tumor ) BUT because we receive the case it will be already metastatic and sometimes it crosses the midline and crushing all the major blood vessels (which indicate bad prognosis)so it is not always possible to remove the tumor surgically, so we add to the treatment combination of chemotherapy,radiotherapy local to the site of the tumor and to the distant metastasis, and some medical centers stimulate the immune system of the body to produce antibodies against the malignant cells what is called immunotherapy (not very common for Neuroblastoma) If the tumor in not resectable we only biopsy, and then refer the child to radiotherapy and chemotherapy hoping for improvement. Question by a colleague: Q:-How many years do these children live? ANS.: Usually very short. 5 years survival rate is 20% in early presented children and 5% for late presented children (depend on the stage).

12 - It is originated from the renal parenchyma. - It is less malignant than Neuroblastoma. - It is more common than Neuroblastoma. - The most common intrarenal tumor of the childhood. - The age of incidence is between 3 and 4 years (it is a little bit older than Neuroblastoma but it can be presented in younger or older age group " 3,4yrs and 3,4yrs"). - Presentation: WILM'S TUMOR (NEPHROBLASTOMA) Usually the mother feels a mass or a lump in the child's abdomen or notices an increase in the size of his abdomen while the child is usually asymptomatic and we try to diagnosis this condition after this presentation, rarely it is discovered by a nurse or by a Paramedical person who feel something unusual in the abdomen. Rarely, especially if the tumor is advanced or enlarged, it might be present with abdominal pain because of the stretch of the capsule or because of local infiltration (the doctor said abdominal mass but I think this is wrong,,,, in the slides it is written abdominal pain and the sequence of the words suggest it,,,, just to be honest ), or might be associated with hematuria(= blood in the urine). Q: Why sometimes this condition is presented with no hematuria? ANS:- It is originated from kidney tissue, but usually it is originated from the periphery or from the cortex of the kidney so sometimes it is presented with no hematuria, but when the tumor infiltrate the pelvicalysial system (major calyx.) it may give hematuria. So hematuria is confirmatory evidence but not very sensitive (we don t depend on hematuria on diagnosis this condition).

13 - Examination:- The child will have in the examination of the abdomen a loin mass (arise from the flank) usually firm in consistency with smooth surface, not tender, usually does not cross the midline usually bimanually palpable. We should differentiate this mass from splenomegaly. What is the gross appearance or the histopathology of Wilm's tumor? This is bisected kidney with big Wilm's tumor, this is the normal kidney tissue and this is the tumor originated from the pole of the kidney, and the tumor here is showing areas of hemorrhage and necrosis and the composition of the cells; there are epithelial cells and mesenchymal cells because it is considered to be of an embryological origin, so we will have a mixture of the epithelial cells, mesenchymal tissue and even there are striated muscle fibers. So the congenital origin of Wilm's tumor is considered strongly. Now we have a child who is 4 years of age, presented as painless abdominal mass and we think, Is itwilm's tumor, Neuroblastoma, or anything else?, what investigations can we do to specify our diagnosis? 1- Plain X- RAY. 2- I.V.U. This is an I.V.U showing complete absence of the collecting system, here in the left, there is hemorrhage obasty (???) in the area, and it is displacing or diverting the pelvicaylical system down because it is originated from the upper pole.

14 So plain X-RAY or I.V.U will not give a definite diagnose, because the definite diagnose is by histopathology, but it will give us an idea that the kidney is the site of origin rather than an extra-renal origin. 3- Chest X-RAY, because the pulmonary metastasis is very common in Wilm's tumor. Early metastasis will show what we call canon balls appearance (not sure about spelling) with no pulmonary symtoms. But late, more advanced tumor might infiltrate all the lung tissue, and you can imagine the clinical picture here, the pt. might have dyspnea, very bad cough and other pulmonary symptoms. 4- Selective renal angiogram to detect the vascularity of the tumor and the displacement of the vessels by the tumor. 5- MRI, US (ultrasound) and CT SCAN: will help to identify the tumor, find out the extent of the lesion and the relation with the surrounding structures. 6- Biopsy: in the advanced stage of the disease where we have a big mass, fixed, hard, and we do not thing that it is possible to remove it surgically, so we so biopsy just to confirm the diagnosis and proceed to other lines of treatment.

15 Mesoblastic Nephroma (Neonatal Nephroblastoma): At the beginning of the lecture we mentioned that the age of the patient is very important, and here there is one type of Wilm's tumor which occurs in the neonatal age (1 st month of age usually) where the kid will be born with an abdominal mass. It is a special type of wilm's tumor in this age group. It has a very good prognosis if it is treated with the proper surgery. It differs from Wilm's tumor by histopathology where there is no lobulation, no necrosis and no areas of hemorrhage, but we have in the histopathology a lot of spindle cells more than the epithelial cells. This is a child with a giant tumor of the left kidney; we can see the edge which is smooth, not lobulated and bimanually palpated, and on investigation it was a tumor of the kidney and after nephrectomy it is proved to be neonatal Wilm's tumor. Q: What is the differential diagnosis of Wilm's tumor clinically? It should be differentiated from all other loin masses, but concerning the kidney it should be differentiated from: 1- Mesenchymal hamartoma. 2- Multilobular cystic kidney or polycystic kidney. These 2 are important because Wilm's tumor may be presented with solid mass with areas of cystic changes or necrosis giving an impression of a cyst. The differentiation is on a histo-pathological background after nephrectomy.

16 Treatment: * Nephrectomy: this is in the case of unilateral Wilm's tumor; we have 5-10% of cases which are bilateral tumors where we can not apply this. *Chemotherapy and Radiotherapy can be added. There is no chemotherapy or radiotherapy for neonates and any child under 2 year of old, nephrectomy is enough. Chemotherapy and cytotoxic drugs used depend on: 1- Age of the patient: the older the age the more the need to these treatments. 2- Size of the tumor: the larger the size, the more the need of these treatment. 3- Histology of the tumor: when the tumor is poorly differentiated and there is intravascular spread. 4- Incomplete removal. 5- Pre-operative or intra-operative rupture or spill. 6- Histological evidence of extra-capsular tumor cells (spread outside the capsule). Prognosis: *Usually better than Neuroblastoma. * In the early stage, when the tumor is localized to the kidney without metastasis, the survival rate is up to 90%. * Even when there is pulmonary metastasis the 5 year survival is 50% after proper surgery, chemotherapy and radiotherapy. * If we do nephrectomy for Wilm's tumor and there is no metastasis and the child is good after 2 years, we considered the child cured.

17 I HOPE THAT THE LECTURE WAS NOT THAT DIFFICULT ALTHOUGH IT IS A BIG ONE, AND IAM SORRY OF BEING LATE. GOOD LUCK IN THE OSCE EXAM Special regards to my group B3 DONE BY: LAITH M. IBRAHEEM