Abdominal Masses

Chapter 43 Abdominal Masses



Roger Berkow




ETIOLOGY


A mass in the abdomen can be caused by a wide variety of conditions and may present varying signs and symptoms depending on the organ or tissue involved, the age of the patient, and whether the mass is cystic or solid, malignant, or benign. The tendency of cancerous tissue to metastasize will also affect the presentation.



What Abdominal Masses Occur in Newborns?


The most common abdominal mass in the newborn period results from obstruction within the renal collecting system, leading to hydronephrosis. Complete obstruction would be detected during pregnancy because of oligohydramnios. Other nonmalignant abdominal masses include teratomas (most specifically in the sacrococcygeal area), duplication of the gut, and choledochal duct cyst. Hepatomegaly and splenomegaly result from storage diseases, portal vein thrombosis, viral and bacterial infections, hemolytic processes, and malignant infiltration.



What Malignancies Are Found in the First Year of Life?


Neuroblastoma is the most common malignant abdominal mass of newborns and in the first year of life. Most arise in the adrenal gland, but enlarged liver and lymph nodes can also be seen in metastatic disease. Neuroblastoma in this age group has a generally good prognosis and can often be treated with surgery alone if localized. Adrenal neuroblastoma with metastatic disease in the liver, spleen, skin, or bone marrow (but not in the bone) is termed stage 4S (“special”). This seemingly advanced disease has the potential for spontaneous regression with no or minimal therapy. More aggressive neuroblastoma may have biologic markers such as amplification of the N-myc oncogene. Wilms’ tumor is the other common malignant abdominal mass in the first year of life. The incidence of this embryonic renal malignancy begins to increase during the second 6 months of life. Other malignancies causing abdominal masses in this age group include germ cell tumors, soft tissue sarcoma, and hepatoblastoma. Lymphomas are rare.



What Masses Are Found in Toddlers and Young Children?


Noncancerous masses in children between ages 1 and 6 include hepatomegaly and splenomegaly caused by infection or storage disease. Ovarian cysts are rarely seen at this age. Malignant lesions include neuroblastoma, Wilms’ tumor, and lymphoma; hepatoblastoma, rhabdomyosarcoma of the vagina, bladder, or retroperitoneum, and ovarian germ cell tumors are seen less often. Constipation can sometimes be confused with an abdominal mass.



Is Neuroblastoma More Aggressive in Older Children?


Neuroblastoma beyond the first year of life often presents with bony pain, pallor, and an abdominal mass plus disseminated disease involving the bone and bone marrow. A child older than 2 years with disseminated neuroblastoma has poor prognosis despite aggressive multimodal therapy (surgery, chemotherapy, and radiotherapy). Paravertebral neuroblastoma may have intraspinal extension and cause spinal cord compression and paralysis of the legs. This medical emergency requires rapid treatment by those familiar with neuroblastoma.



What Is Wilms’ Tumor?


Wilms’ tumor is the second most likely cause of a malignant abdominal mass in the 1- to 6-year-old child. Parents often find a flank swelling during bathing or changing of diapers. Wilms’ tumor is usually localized at diagnosis but can metastasize to lymph nodes, lungs, and liver. The prognosis is excellent, even with advanced disease. The “classic triad” of abdominal mass, hematuria, and hypertension is rare.



What Other Malignancies Cause Abdominal Masses?


Lymphoma occurs less often than neuroblastoma or Wilms’ tumor. It can present with intussusception, especially in children older than 5 years, or hepatomegaly/splenomegaly. In these situations the metabolic problems associated with “tumor lysis syndrome” (hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia) must be anticipated. Rhabdomyosarcoma in the bladder or vagina can present with hematuria or vaginal bleeding, respectively, along with a pelvic or abdominal mass. It can also present as a retroperitoneal mass with or without obstruction of renal outflow or crampy abdominal discomfort. The extent of disease and the specific pathologic subtype of the rhabdomyosarcoma determine prognosis. Hepatoblastoma, ovarian germ cell tumors, and Ewing’s sarcoma of the retroperitoneum or pelvis must also be considered in the differential diagnosis of abdominal masses in this age group.

< div class='tao-gold-member'>

Related posts:

  1. Children with Special Needs
  2. Immunization
  3. Bleeding and Bruising
  4. Growth

Stay updated, free articles. Join our Telegram channel
Tags:
Jun 19, 2016 | Posted by in PEDIATRICS | Comments Off on Abdominal Masses

Full access? Get Clinical Tree
Get Clinical Tree app for offline access