A 3-year-old boy is found to have spontaneous bursts of non-rhythmic conjugate eye movements in various directions, as well as hypotonia and myoclonus. Physical examination also reveals an abdominal mass. A CT scan shows a mass in the adrenal gland. Which of the following statements is false regarding the patient's condition?
A renal mass seen on prenatal check-up is most probably:
Opsoclonus-myoclonus is a phenomenon seen in:
Which of the following childhood tumor uses N-myc gene amplification for its prognosis?
What is the most common malignant tumor of the kidney in children?
A 4-year-old boy was diagnosed with a malignancy. On physical examination, he was found to have aniridia. Which of the following tumors is associated with aniridia?
On USG, a mass was found in the abdomen which was displacing the kidney laterally in a 1-year-old child. What is the most likely diagnosis?
Most common malignant tumour in childhood:
Which one of the following regarding abdominal pediatric surgery is correct?
Most common cause of acute intestinal obstruction in children is
Explanation: ***Immunohistochemical detection of chromogranin is not useful for diagnosis.*** - This statement is **false** because **neuroblastoma** cells, which originate from neural crest cells, commonly express **chromogranin A** and C, along with other neuroendocrine markers like **synaptophysin** and **neuron-specific enolase (NSE)** [1]. - **Immunohistochemical staining** for chromogranin is thus a **useful diagnostic tool** to confirm the neuroendocrine differentiation of the tumor [1]. *The most common site of tumor is adrenal medulla.* - This statement is **true**. Approximately **50% of neuroblastomas** originate in the **adrenal glands**, specifically the adrenal medulla, because it is derived from neural crest cells, the precursor cells for neuroblastoma [1]. - Other common sites include the paraspinal ganglia, such as the posterior mediastinum, pelvis, and neck. *70-80% of tumors are associated with elevated production of catecholamines.* - This statement is **true**. Neuroblastoma cells often retain the ability to synthesize and secrete **catecholamines** (**epinephrine, norepinephrine, dopamine**) [1]. - Elevated levels of **vanillylmandelic acid (VMA)** and **homovanillic acid (HVA)**, which are the **breakdown products (metabolites) of catecholamines**, are detected in the urine of 70-80% of patients and serve as **important diagnostic and prognostic markers** [1]. *Rearrangement or deletion of short arm of chromosome 1 is seen in 25-35% of cases.* - This statement is **true**. **Deletion** or **rearrangement** of the **short arm of chromosome 1 (1p36)** is a common **cytogenetic abnormality** found in 25-35% of neuroblastomas. - This genetic alteration is often associated with **poor prognosis** and more aggressive disease behavior. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 483-487.
Explanation: ***Mesoblastic nephroma*** - This is the most common **congenital renal tumor** and is often detected antenatally or in the **neonatal period**. - It is typically a **benign tumor** that presents as a solid, well-circumscribed renal mass. *Neuroblastoma* - While it can present as an abdominal mass in infants, **neuroblastoma** usually arises from adrenal glands or sympathetic ganglia, not primarily the kidney itself. - It often shows features of calcification and can be associated with elevated **catecholamines**. *Wilms' tumor* - **Wilms' tumor** is the most common childhood renal malignancy, but it is typically diagnosed in older infants and young children (peak incidence at 2-3 years), less commonly detected definitively on prenatal check-ups. - Prenatal detection of **Wilms' tumor** is rare, and it usually grows rapidly postnatally. *Renal sarcoma* - **Renal sarcoma** is an extremely rare primary renal tumor in children, making it a much less likely diagnosis than mesoblastic nephroma for a prenatal renal mass. - These tumors tend to be aggressive but are statistically much less common in the prenatal period.
Explanation: ***Neuroblastoma*** - **Opsoclonus-myoclonus syndrome (OMS)** is a rare paraneoplastic neurological disorder primarily associated with childhood neuroblastoma. - It is characterized by rapid, irregular eye movements (**opsoclonus**), brief, involuntary muscle jerks (**myoclonus**), ataxia, and irritability. *Wilm's tumor* - Wilms' tumor (nephroblastoma) is a kidney tumor of childhood and is not typically associated with opsoclonus-myoclonus syndrome. - While it is also a pediatric cancer, its paraneoplastic manifestations are different and do not include OMS. *Meningioma* - Meningiomas are typically slow-growing tumors arising from the meninges in adults, and are not associated with opsoclonus-myoclonus. - Paraneoplastic syndromes are rare with meningiomas, and OMS is not one of them. *Cortical tuberculoma* - A cortical tuberculoma is a granulomatous lesion in the brain caused by Mycobacterium tuberculosis, often seen in individuals with tuberculosis. - While it can cause neurological symptoms like seizures, headaches, and focal deficits, it does not cause opsoclonus-myoclonus syndrome.
Explanation: ***Neuroblastoma*** - **N-myc gene amplification** is a crucial **prognostic indicator** in neuroblastoma, correlating with aggressive disease and poor outcomes [1]. - Neuroblastoma is a **childhood cancer of neural crest origin**, often presenting as an adrenal mass or in sympathetic ganglia. *Nephroblastoma* - Also known as **Wilms tumor**, it is a childhood kidney cancer. - Its prognosis is more strongly associated with histology (e.g., **anaplasia**) and specific gene mutations like **WT1**, not N-myc amplification. *Retinoblastoma* - This is a **childhood eye cancer**. - Its prognosis is primarily linked to the presence of **RB1 gene mutations** and the extent of retinoblastoma gene protein (pRB) expression, not N-myc. *Rhabdomyosarcoma* - An aggressive **childhood soft tissue sarcoma** with skeletal muscle differentiation. - Prognostic factors often include clinical staging, histology (e.g., **alveolar vs. embryonal**), and specific genetic translocations like **PAX-FOXO1**, rather than N-myc amplification. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 486-487.
Explanation: ***Wilms tumor*** - Wilms tumor, or **nephroblastoma**, is the most common type of kidney tumor in children, typically presenting with an **abdominal mass** [2]. - Most patients are diagnosed between the ages of **2 and 5** [3], and it is often associated with syndromic conditions like **WAGR syndrome** [1]. *PCKD* - **Polycystic Kidney Disease (PCKD)** is a genetic disorder that leads to kidney enlargement but is not classified as a tumor. - While it can lead to complications like hypertension, it does not typically present as a **neoplastic mass** in children. *Angioliposarcoma* - This is a rare tumor that occurs primarily in adults, characterized by **fatty tissue** and vascular infiltrations, making it an uncommon kidney tumor in children. - Typically, renal tumors in children are **Wilms tumor** rather than **sarcomas** like angioliposarcoma. *Neuroblastoma* - Neuroblastoma is an **extrarenal tumor** that commonly arises from the adrenal glands or sympathetic nervous tissue [3], rather than directly from the kidney. - It presents with **abdominal masses** but is distinct from kidney tumors, which makes it less relevant in the context of renal tumors in children. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 487-488. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 488-490. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 483-484.
Explanation: ***Correct: Nephroblastoma*** - **Wilms' tumor**, or nephroblastoma, is a common pediatric renal malignancy that can be associated with **aniridia** as part of the **WAGR syndrome**. - **WAGR syndrome** is caused by a deletion on chromosome 11p13, which includes the *WT1* gene (responsible for Wilms' tumor) and the *PAX6* gene (responsible for aniridia). - Other features include **Genitourinary anomalies** and intellectual disability (formerly called mental **Retardation**). *Incorrect: Retinoblastoma* - This is a malignancy of the **retina** and is primarily associated with mutations in the **RB1 gene**. - While it affects the eye, it does not typically present with or cause aniridia. *Incorrect: Hepatoblastoma* - This is a rare malignant tumor of the **liver** and is not directly associated with aniridia. - It is sometimes linked to genetic syndromes like **Beckwith-Wiedemann syndrome** or familial adenomatous polyposis. *Incorrect: Medulloblastoma* - This is a malignant **brain tumor** originating in the cerebellum and is not associated with aniridia. - It often presents with symptoms related to increased intracranial pressure like **hydrocephalus** or ataxia.
Explanation: ***Neuroblastoma*** - A retroperitoneal mass displacing the kidney laterally in an infant is highly characteristic of **neuroblastoma**, which originates from neural crest cells in the adrenal gland or sympathetic ganglia. - The key finding is **extrarenal origin** - the mass pushes the kidney aside rather than arising from within it. - Most common extrarenal abdominal mass in children under 2 years. *Wilms' tumor* - This is an **intrarenal mass** that originates within the kidney parenchyma. - Wilms' tumor **expands and distorts the kidney** rather than displacing it laterally from outside. - Most common renal tumor in children (peak age 3-4 years), presenting with abdominal mass, hematuria, and hypertension. *Renal cell carcinoma* - Exceedingly **rare in a 1-year-old child** - primarily an adult malignancy (typically >40 years). - Would be an intrarenal mass, not an extrarenal mass displacing the kidney laterally. *All of the options* - Incorrect because the specific imaging finding of **lateral kidney displacement** indicates an extrarenal origin, which is pathognomonic for neuroblastoma, not the intrarenal tumors listed.
Explanation: ***Leukaemia*** - **Leukaemia** is the **most common paediatric malignancy**, accounting for approximately 30% of all childhood cancers. - It involves the uncontrolled proliferation of abnormal white blood cells, primarily in the **bone marrow** and blood. - **Acute lymphoblastic leukaemia (ALL)** is the most common subtype. *CNS tumours* - **CNS tumours** (brain and spinal cord tumours) are the **second most common** paediatric malignancy, accounting for 20-25% of childhood cancers. - Include medulloblastoma, gliomas, and ependymomas. - While common, they are less frequent than leukaemia. *Rhabdomyosarcoma* - **Rhabdomyosarcoma** is a malignant tumour of **mesenchymal origin**, typically affecting skeletal muscle. - While it is the most common soft tissue sarcoma in children, it is not the most common overall childhood malignancy. *Neuroblastoma* - **Neuroblastoma** is a malignant tumour derived from **neural crest cells**, often arising in the adrenal glands or sympathetic nervous system. - It is one of the most common solid extracranial tumours in children but is less common than leukaemia.
Explanation: ***Incision can be closed with absorbable suture*** - **Absorbable sutures** are commonly used in pediatric abdominal surgery for closing deeper layers and sometimes skin, as they degrade over time and do not require removal. - This is particularly beneficial in children to avoid the trauma and discomfort of suture removal and to promote good cosmetic outcomes. *Transverse abdominal incision is always used* - While **transverse incisions** are often preferred in pediatric abdominal surgery for their good cosmetic results and lower incidence of incisional hernias, they are not *always* used. - Other incisions, such as **vertical midline incisions**, may be utilized depending on the surgical exposure required, the specific pathology, or the surgeon's preference. *Bowel must be always anastomosed in double layer* - **Bowel anastomoses** in pediatric surgery can be performed using either a **single-layer** or **double-layer** technique. - The choice depends on surgeon preference, the specific bowel segment involved, and the patient's condition, with both methods demonstrating comparable outcomes in many situations. *Skin over abdomen can never be closed with subcuticular sutures* - **Subcuticular sutures** are frequently used for skin closure in pediatric abdominal surgery, especially for their excellent cosmetic results and to avoid external suture removal. - This technique places the suture material under the skin surface, minimizing scarring and being well-suited for a child's healing skin.
Explanation: ***Intussusception*** - **Intussusception** is the most common cause of **acute intestinal obstruction** in children, particularly between 3 months and 3 years of age. - It occurs when a segment of the intestine telescopes into an adjacent segment, leading to obstruction and potentially **ischemia**. *Inguinal hernia* - While an **incarcerated inguinal hernia** can cause intestinal obstruction, it is less common than intussusception as the primary cause of acute obstruction in children generally. - It is more frequent in **neonates and infants** but overall incidence of obstruction is lower than intussusception. *Volvulus* - **Volvulus** refers to a twisting of the intestine on its mesentery, often associated with **malrotation**, leading to obstruction and vascular compromise. - While a serious cause of obstruction, especially in neonates, it is less common overall than intussusception in the pediatric population. *None of the options* - This option is incorrect because **intussusception** is a recognized and frequent cause of acute intestinal obstruction in children.
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