This document discusses and classifies both solid and cystic pediatric abdominal tumors. It provides detailed information on common tumors such as Wilms tumor (nephroblastoma), neuroblastoma, hepatoblastoma, teratoma, intestinal lymphoma, and rabdomyosarcoma. For each tumor, it describes characteristics such as presentation, pathology, imaging findings, staging, and treatment approaches including surgery and chemotherapy. It also covers cystic lesions including hydronephrosis, mesenteric cysts, ovarian cysts, pseudo pancreatic cysts, and liver cysts. The document serves as a comprehensive reference for the diagnosis and management of major pediatric abdominal tumors.

1. Solid And Cystic Pediatric
Abdominal Tumors
Tarek A. Hassan
FRCS,MD
Prof. of Pediatric Surgery
Ain Shams University

2. Classification
Solid Tumours:
*Nephroblastoma (Wilm’s Tumour ).
*Neuroblastoma.
*Hepatoblastoma.
*Teratoma.
*Intestinal Lymphoma.
*Rabdomyosarcoma.

3. Classification
Cystic Swellings:
*Hydronephrosis
*Mesenteric and Duplication Cysts
*Liver cysts (Simple, Mesenchymal
hamartoma)
*Pseudo pancreatic Cyst
*Ovarian cysts
*Teratoma

4. Wilm’s Tumor (Nephroblastoma)
The second most common solid intra-
abdominal malignant tumor in children.
Commonest renal mass in children
Peak incidence: 3-5 years of age.

5. Wilm’s Tumour: Pathology
Derived from primitive metanephric
blastema cells.
Histopathology: Triphasic (three cell types)
stromal, epithelial, and blastemal. Thus
may contain tissue not found in the normal
kidney eg. Skeletal, muscles, cartilage and
squamous epithelium.

6. Wilm’s Tumour: Histological pattern
Favourable Histology
Unfavourable Histology
*Anaplastic (focal or diffuse)
*Clear cell sarcoma
*Rhabdoid tumour

7. Diagnosed by the
presence of a
solid, intrarenal
mass causing
intrinsic distortion
of the calyceal
collecting system.
Metastases: lung,
occasionally liver.
Wilm’s Tumor

8. Wilm’s Tumor: Presentation
Presentation: abdominal (flank) mass +/-
pain, fever.
Other presentations: malaise, weight loss,
anemia, hematuria, left varicocele and
hypertension.

9. Wilm’s Tumour: Investigation
Plain X-ray Abdomen.
Abdominal U.S.
C.T. Abdomen.
MRI Abdomen.
Chest: Plain X-ray and C.T.

10. Wilm’s Tumour: Abdominal U.S.

11. Wilm’s Tumour: C.T. Abdomen

12. Wilm’s Tumour: MRI Abdomen

13. Wilm’s Tumour: Chest Plain X-ray
and C.T.

14. Staging by National Wilm’s Tumor
Study Group:
Stage I: Tumor limited to kidney and
completely resected.
Stage II: Tumor extends beyond the
kidney but completely excised.
Stage III: Residual non-hematogenous
tumor confined to the abdomen.
Stage IV: Hematogenous metastasis.
Stage V: Bilateral tumors.

15. Wilm’s Tumour: Treatment
Surgical Excision followed by Chemotherapy +/-
Radiotherapy according to the stage and histology
(favorable or unfavorable).
Aim of surgery: Radical nephrectomy without
spillage + accurate staging (spread of disease).
Chemotherapy commonly used: Actinomycin D
(A), Vincristine (V), Doxorubicin (D), Cytoxan (C).

16. Wilm’s Tumour: NWTS-4 treatment
STAGE HISTOLOGY NEPHRE
CTOMY
CHEMO
THERAPY
RADIO
THERAPY
I FV, UFV + A, V NO
II FV + A, V NO
III, IV FV + A, V, D YES
II, III, IV UFV + A, V, D +/-
C
YES

17. Wilm’s Tumour: Surgical Excision

18. Wilm’s Tumor : Prognosis
Disease-free survival is 95% for Stage I
and approximately 77% for all patients.
Good prognosis:
-Stage I & II
-Para-aortic LN: -ve
-Favorable histology
-No tumor ruptured during surgery

19. Congenital Mesoblastic Nephroma
presents in infants < 30 days of age
(< 6 months), is commonly benign
and invasive locally.
Operative removal is curative.
Ruptured of tumor increases
recurrences.
Chemo and radiotherapy are not
indicated.
Mesoblastic Nephroma

20. Neuroblastoma
most common extracranial solid tumor
of childhood.
8-10% of all pediatric malignancies
Median age at diagnosis is 2 years.
Arises from the adrenals or sympathetic
chain
Higher frequency seen in certain
syndromes (Myoclonus-opsoclonus
syndrome ,Watery diarrhea )

21. Pathology
“Small round blue cell” tumors
 Originates from neural crest cells in the sympathetic
nervous system
Arises from the adrenals or sympathetic chain
3 subgroups
 Neuroblastoma- most primitive
 Ganglioneuroma- benign and mature
 Ganglioneuroblastoma- in between
Secrete neurogenically derived substance
 Urinary catecholamines in 75-90%
*VMA & HVA
 Others
*Neuron specific enolase (NSE)
*Ferritin

22. Pathology : Pseudorosettes
Shimada Classification:
favorable histology&
unfavorable histology
NBL metastasized to the
bone marrow
Clumps of tumor cells

23. Cytogenetics
Chromosomal abnormalities in most
cases of NBL
N-myc amplification (normally 2 copies)
 >10 copies/cell
 30% of NBL
 Poor prognosis
Ploidy
 Hyperdiploid = DNA index > 1.0
 Good prognosis, at least in those < 2 years

24. Presentation
Variable
 Median age is 2 years, so S/S are vague
Constitutional
 Fever, malaise, irritability
Mass
 Posterior mediastinal mass on CXR(esp in infants)
 Palpable abdominal mass
 Hard, painless mass in the neck
Mass effect, dependent on location
 Abd pain/obstruction
 Lower limb paresis from a paraspinal tumor

25. Metastasis
>50% have metastatic disease at
diagnosis
Sites
 Lymph nodes
 Bone marrow
 Liver
 Skin
 Orbit
 Bone

26. Raccoon eyes
Metastasis to
the orbit
Unilateral or
bilateral
May start with
just proptosis

27. Skin findings S.C. metastasis
May be dark or
skin colored

28. Neuroblastoma: Work-up
Blood
 CBC
 Ferritin
 NSE
 LDH
Urine
 Catecholamines
VMA / HVA
Tumor tissues
 Shimada class.
 N-myc
 1p deletion
Radiology
 CXR
 Abdominal U.S.
 C.T. and MRI
 Skeletal survey
 Bone scan
 MIBG
Bone marrow
 Aspirate and biopsy
from both post iliac
crests

29. Neuroblastoma: C.T.

30. Neuroblastoma: MIBG scan

31. International Neuroblastoma
Staging System (INSS)

32. Treatment
Surgery
 Localized tumors that don’t encase vasculature
 Complete resection = excellent chance for cure
 Palliative treatment for tumors compressing vital
organs
Chemotherapy
 The mainstay of therapy since most are metastatic
 May be very intensive requiring stem cell rescue
Radiation
 Used for localized but unresectable tumor (stage III)
 Control of tumor that is unresponsive to chemo

33. Neuroblastoma: Treatment
Stage I: Complete surgical resection.
Stage II: Incomplete surgical resection 
Chemotherapy  second look surgical
resection.
Stage III: Incomplete surgical resection 
Chemotherapy +/- Radioth.  second look
surgical resection.
Stage IV: Chemotherapy  Surgical
resection if possible.

34. Neuroblastoma: Risk Factors
PARAMETER HIGH RISK LOW RISK
Age >1 yr, esp >2 <1yr
Stage IV, some III I, II, III, IVs
Shimada class. Unfavourable Favourable
N-myc >10 copies <10, esp <3
1p36 Present Absent
Ploidy Diploid Hyperploid
Trk-expression Absent Present
Ferritin serum >145-150ng/ml <145-150ng/ml
LDH serum >1500 <1500

35. Neuroblastoma: Surgical Excision

36. Pelvic Neuroblastoma

37. Pelvic Neuroblastoma

38. Pelvic Neuroblastoma

39. Liver Tumors
Hepatoblastoma and hepatocellular carcinoma
2% of all malignancies in childhood and 15% of
malignant abdominal masses

40. Hepatoblastoma
Hepatoblastoma is the
most common primary
malignant neoplasm of
the liver in children
Males, < four year of age

41. Hepatoblastoma: Investigations
Plain X-ray, U.S., C.T., MRI: predict
resectability and tumor extension.
Tumour markers: alpha-fetoprotein and
gamma-glutamyl transferase II

42. Hepatoblastoma: Investigations

43. Hepatoblastoma: Treatment
Surgery + Chemotherapy +/- Radiotherapy
Surgery: Optimum treatment is complete
resection.
Chemotherapy:
*Adjuvant following resection.
*Pre-operative for non-resectable.
*Palliative for metastatic disease.
Radiotherapy: for non-resectable tumor to
reduce its size.

44. Hepatoblastoma: Treatment
Surgical Excision and Chemotherapy.

45. Hepatoblastoma: Preoperative
chemotherapy

46. Teratoma
Arises from Totipotent cells thus contains tissues
(bone, teeth, cartilage, hair and fat) foreign to
the site of origin.
Commonest site: Sacrococcygeal.
Other sites: Gonads, Retro-peritoneal,
Cervical.
Solid, cystic or mixed.
Benign or Malignant from the start .
High incidence of malignant transformation if not
resected.

47. Teratoma: Investigations
Plain X-ray, U.S., C.T.
High Alpha Feto-protien.

48. Sacrococcygeal & Cervical
Teratomas

49. Retro-peritoneal Teratoma

50. Retro-peritoneal Teratoma

51. Teratoma: Treatment
Surgical Excision.
Chemotherapy if histopathology proves it
to be malignant.

52. Ovarian tumours
Uncommon childhood malignancies (1%)
Presents as an Abdominal Mass or Acute
Abdomen in cases of torsion.
Common histology is germ cell:
dysgerminoma, teratoma, and endodermal
sinus tumor.
Other: Epithelial (older adolescent), lipid-
cell, and gonadoblastoma.

53. Ovarian Tumour: Investigations
Plain X-ray, U.S., C.T., MRI
Alpha feto protein

54. Ovarian Teratoma

55. Ovarian Dysgerminoma

56. Torsion Ovarian tumours

57. Ovarian Tumours: Treatment
Surgical excision with staging.
Chemotherapy for malignant cases.

58. Intestinal Lymphoma
Presents as an Abdominal Mass.
High incidence of Burkitt’s Lymphoma.
Diagnosis: U.S. and C.T.
Treatment: Chemotherapy
Surgery is only indicated if patient
presents with intestinal obstruction.

59. Intestinal Lymphoma

60. Rabdomyosarcoma

61. Rabdomyosarcoma

62. Mesenteric Cysts
Presents by Abdominal mass.
Diagnosis: U.S. and C.T.
Treatment: Surgical Excision

63. Mesenteric Cysts

64. Ovarian Cyst
Mostly functional and presents in the
neonatal period.
Can be diagnosed antenatally.
Liable for torsion.
Diagnosis: U.S ,C.T
Treatment is surgical excision of the cyst if
its size exceeds 4 to 5 cm.

65. Ovarian Cyst

66. Ovarian Cyst

67. Pseudo pancreatic Cyst
Commonly follows abdominal trauma
50% resolves spontaneously
Intervention is indicated
if it persists >4-6 W ,its size >4-6 cm,
develops complications
Surgical internal drainage, percutaneous
U.S. or C.T. guided drainage , endoscopic
internal drainage

68. Pseudo pancreatic Cyst

69. Liver Cysts
Mesenchymal Hamartoma and Solitery
Liver Cyst.
Presents in the first year of life as a rapidly
growing abdominal mass.
Diagnosis: U.S. and C.T.
Treatment: Excision.

70. Mesenchymal Hamartoma

71. Mesenchymal Hamartoma

72. Solitery Liver Cyst

73. Hydronephrosis
Commonest cystic abdominal swelling.
May be due to U.P.J., P.U.V., Megaureter,
V.U.Reflux.
Diagnosis: U.S., Isotope scan
Treatment: according to the cause.

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