Quiz

Two-year-old boy presented with generalized bone pains and hepatosplenomegaly. Bone marrow biopsy/aspirate

Adamantinomatous craniopharyngioma

Glomus tumor

Five-year-old boy with mass in the sellar region near third ventricle. Tumor biopsy

CASE 3

History

Four-year-old girl presented with a painful 1 cm subungual mass on her left index finger

Anaplastic large cell lymphoma

Eight-year-old boy with peripheral lymphadenopathy and very high fever. Cervical lymph node biopsy showed tumor cells to be positive for CD30 and AlK-1

Teratoma (mature and immature components present)

Alveolar capillary dysplasia with misaligned veins

CASE 6

History

Newborn girl with severe respiratory distress and pulmonary hypertension. Lung biopsy

Ten-month-old infant with a large retroperitoneal mass

Congenital hepatic fibrosis

Angiomatoid fibrous histiocytoma

Twelve-year-old boy with hematemesis and melena. He has a past history of ARPKD. Liver biopsy

CASE 8

History

Teenager with malaise, fever, and mass in popliteal fossa. Tumor biopsy was done. Tumor cells are positive for Calponin, CD68, and EMA

Congenital pulmonary airway malformation (type I)

Blue nevus

CASE 10

History

Smooth surfaced 1 cm dark brown, dome-shaped lesion on scalp of a 9-year-old boy. Skin biopsy. Lesional cells are positive for HMB45

Neonate with progressive respiratory distress; chest radiograph shows a multicystic mass. The mass was resected

Burkitt lymphoma

Eight-year-old African boy with a mass in ileocecal region. Tumor biopsy

Calcifying nested stromal-epithelial tumor of liver

Ten-year-old boy with Cushing syndrome and hepatic mass. Liver tumor biopsy

Hodgkin lymphoma nodular sclerosis type

Sixteen-year-old girl with cervical lymphadenopathy. The neoplastic cells are positive for CD15 and MUM1

Epithelioid sarcoma

Eighteen-year-old boy with a firm to hard palpable mass in the soft tissue of hand. The lesional cells are positive for AE1/AE3. Tumor biopsy

Choroid plexus papilloma

Eleven-year-old boy presented with long-standing history of hydrocephalus. On imaging a mass was seen in right lateral ventricle of brain. Tumor cells are positive with S100 and focally with GFAP

Chondroblastoma

Enterobius vermicularis

Nine-year-old boy with pain and swelling in the knee. Tumor cells are positive with S100 and vimentin. Tumor biopsy

CASE 17

History

Four-year-old girl from Haiti who underwent appendectomy for mild features of appendicitis. Appendectomy specimen

Chordoma

Fifteen-month-old boy presented with a slow-growing mass in sacrum. Tumor biopsy

Xp11.2 translocation renal cell carcinoma

Three-year-old girl presented with kidney mass that showed nuclear expression of TFE3 immunostain and had Xp11.2 translocation

Ameloblastoma

Congenital infantile fibrosarcoma

Two-year-old girl with painless swelling and deformity in maxilla. Imaging showed a soap bubble appearance. Neoplastic cells are positive for CK5. Tumor biopsy

CASE 21

History

Premature infant with recurrent large right shoulder mass. Tumor was positive for t(12;15) ETV6-NTRK3 gene rearrangement. Neoplastic cells are positive for vimentin

Fibrous hamartoma of infancy

Synovial sarcoma

One-year-old with mass in right axilla. Lesional cells are positive for vimentin and actin. Tumor biopsy

CASE 23

History

Long-standing deep-seated mass in ankle of a 12 year old. Tumor cells are positive for EMA and vimentin

Desmoplastic small round cell tumor

Embryonal rhabdomyosarcoma

Fourteen-year-old boy with intra-abdominal mass. Tumor cells are positive for WT-1. Molecular studies show t(11;22), WT1-EWS gene rearrangement

CASE 25

History

Three-year-old boy with a mass in the paratesticular region. Neoplastic cells are diffusely positive for desmin and show weak patchy positivity for myogenin. Tumor biopsy

Eosinophilic esophagitis

Chondromyxoid fibroma

Two-and-a-half-year-old girl with wheezing and failure to thrive. Biopsy from proximal esophageal mucosa

CASE 27

History

Fifteen-year-old with a lytic well-circumscribed mass in metaphysis of right tibia. Tumor biopsy

Ewing sarcoma

Ten-year-old boy with pain, fever, and weight loss. Lytic destructive lesion of femur on imaging. Tumor biopsy

Extra-adrenal paraganglioma

Juvenile hemangioma

Eighteen-year-old girl with MEN2a syndrome and recurrent tumor in front of lumbar vertebra. Tumor biopsy

CASE 30

History

Six-month-old boy with a large pink papule on neck. The neoplastic cells are positive for CD31 and GLUT-1. Biopsy from the lesion

Fibrous dysplasia

Focal cortical dysplasia type IIA

Seven-year-old girl with spontaneous fracture of the orbital bone. Bone biopsy

CASE 32

History

Eight-year-old boy with progressive cognitive impairment and seizures. Imaging did not show any mass lesion. Biopsy from frontal lobe of brain

Giant cell fibroblastoma

Giardia lamblia

Five-year-old boy with painless subcutaneous mass in trunk. Tumor cells are positive for vimentin and CD34, and negative for S100. Tumor biopsy

CASE 34

History

Six-year-old boy with chronic diarrhea and malabsorption after he returned from a camping trip. Duodenal biopsy

Granular cell tumor

Fundic gland polyp

Eleven-year-old boy with lesion in perianal skin. Cells are S-100 and PAS positive. Tumor biopsy

CASE 36

History

Fourteen-year-old girl was on proton pump inhibitors for hyperacidity. Endoscopy of the gastric fundus showed an incidental 5 mm mucosal nodule

Hodgkin lymphoma-mixed cellularity

Sixteen-year-old boy with fever, night sweats, and enlarged mediastinal lymph nodes. Tumor cells are positive for CD15, CD30, and EBV. Lymph node biopsy

Hepatoblastoma epithelial type (fetal and embryonal)

Six-month-old boy with Beckwith-Wiedemann syndrome and abdominal mass. Liver mass was resected. Nuclear beta-catenin positivity was noted

Hodgkin lymphoma-nodular lymphocyte predominant

Testicular regression syndrome

Enlarged mediastinal lymph nodes in a 13-year-old girl. Neoplastic cells are positive for OCT-2, CD20, BOB1, and CD45. Lymph node biopsy

CASE 40

History

Six-year-old boy with ambiguous genitalia and history of right testicular cryptorchidism. Biopsy is from a 1 cm right inguinal mass

Kikuchi lymphadenitis

Inclusion body fibromatosis

Seventeen-year-old girl with fever, cervical lymphadenopathy, and negative infectious workup. Flow cytometry findings were not suggestive of lymphoma. Lymph node biopsy

CASE 42

History

A 1 cm nodular mass on the dorsum of index finger in a 6-month-old infant. Biopsy from the mass

Extramedullary myeloid sarcoma

Myofibroma/myofibromatosis

Orbital mass in a 2-year-old girl with a history of unknown malignancy. Neoplastic cells are positive for myeloperoxidase and CD68. Biopsy from the orbit

CASE 44

History

Seven-month-old girl with a raised hard violaceous mass 6 cm × 6 cm, on left side of face. Biopsy from mass showed spindle-shaped cells positive for smooth muscle actin and vimentin stain

Granuloma annulare

Fifteen-year-old boy with an erythematous, scaling and pruritic 2 cm mass on dorsum of hand. Biopsy from the mass

Pilocytic astrocytoma

Seven-year-old girl with a well-circumscribed, slow-growing cerebellar mass. On imaging the mass was contrast enhancing and cystic in appearance. Brain tumor biopsy

Aplastic anemia with myelodysplasia

Six-year-old boy with anemia, bleeding, and recurrent infections. Cytogenetic studies showed monosomy 7. Bone marrow biopsy/aspirate

Juvenile granulosa cell tumor

Juvenile xanthogranuloma

Nine-year-old girl with precocious puberty. Biopsy from ovarian tumor

CASE 49

History

One-year-old girl with circumscribed yellow papular mass on dorsum of tongue. Biopsy from the mass showed lesional cells to be positive for CD68 and negative for S100

Inflammatory bowel disease-Crohn colitis

Medulloblastoma

Sixteen-year-old girl with abdominal pain, diarrhea, and bloody stools. Biopsy from cecum

CASE 51

History

Five-year-old girl with headaches and rapidly enlarging posterior fossa mass. MIB-1 was very high. Brain tumor biopsy

Leydig cell tumor

Eight-year-old boy with virilization, precocious puberty, and testicular mass. Testicular biopsy

Mature ganglioneuroma

Eight-year-old boy with posterior mediastinal mass. Mass was resected and it showed a gray-white solid homogenous cut surface

Glioblastoma multiforme

Seven-year-old boy with a solitary, rapidly enlarging supratenticular brain mass. On imaging, the mass was ring-enhancing

Atypical teratoid rhabdoid tumor

Seventeen-month-old boy with rapidly growing mass in posterior fossa. Tumor cells are INI-1 negative but positive for EMA, SMA, and GFAP. Biopsy from the brain tumor

Pilomatrixoma

Medullary carcinoma thyroid gland

Three-year-old girl with a firm to bony hard mass on left cheek. Cut surface of the mass was chalky white

CASE 57

History

Teenage boy with MEN2a and increased serum calcitonin. Cells are positive for calcitonin and congo-red staining is identified. Biopsy from thyroid gland

Langerhans cell histiocytosis

Five-year-old boy with a tender, palpable lytic mass in the skull. Biopsy from the skull mass

Graft versus host disease-stomach

Non-alcoholic fatty liver disease (NAFLD)

Twelve-year-old boy who developed severe diarrhea after allogenic bone marrow transplant

CASE 60

History

Markedly obese 14-year-old boy with impaired liver function tests. Liver biopsy

Metastatic neuroblastoma bone marrow

Bone marrow biopsy in a 1-year-old infant who has a large mediastinal mass. The neoplastic cells are positive for CD56, tyrosine hydroxylase and PGP9.5

Mesenchymal hamartoma liver

Eleven-month-old boy with a large liver mass. The mass was well circumscribed and had a solid-cystic cut surface

Pituitary adenoma

Slow-growing sellar mass in a 13-year-old girl who presented with history of headaches and galactorrhea. Tumor cells are positive for chromogranin

Melanotic neuroectodermal tumor of infancy

Osteolytic mass lesion in maxilla of newborn infant. Mass was brown-black in color and solid in appearance. Tumor cells are positive for HMB45, CK, and NSE

Malignant peripheral nerve sheath tumor

Nodular fasciitis

Recurrent mass in gluteal region in a 12-year-old boy with NF1. Tumor biopsy

CASE 66

History

Eleven-year-old boy with a rapidly enlarging 3 cm nodular painful mass in forearm. Biopsy from the mass

Pleuropulmonary blastoma

Mesothelioma

Four-month-old girl with shortness of breath and lung mass. The mass was solid-cystic and hemorrhagic in appearance. Right lung lobectomy was done

CASE 68

History

Peritoneal mass in 18-year-old boy with prior history of radiotherapy. Tumor cells are positive for CK5/6, WT-1, and calretinin. Biopsy from the mass

Nasopharyngeal carcinoma

Fourteen-year-old African boy with a metastatic tumor in left cervical lymph node. The tumor cells were positive for cytokeratin and Epstein-Barr virus. Lymph node biopsy

Poorly differentiated neuroblastoma

Twenty-month-old boy with a large abdominal mass, fever, and weight loss. The lesion was positive for chromogranin, tyrosine hydroxylase and negative for CD99. Biopsy from the adrenal gland mass

Malignant mucinous cystadenocarcinoma of ovary

Fifteen-year-old girl with a large solid-cystic mucinous mass of right ovary. Neoplastic cells are positive for CEA and CA125. Biopsy from ovarian tumor

Osteosarcoma

Fourteen-year-old boy with a lytic mass in the distal femur. Bone was resected and showed a necrotic tumor mass

Solid pseudopapillary neoplasm of pancreas

Nineteen-year-old girl with a multinodular mass in her pancreas. Grossly, the tumor was partly necrotic and cystic. Tumor cells are positive for vimentin, CD10, and progesterone. Tumor biopsy

T-cell acute lymphoblastic leukemia

Six-year-old boy with weight loss, fever, bleeding, and anemia. Bone marrow biopsy

Pancreatoblastoma

Two-year-old girl with mass in the pancreas. Tumor cells are positive for cytokeratin and beta-catenin, and negative for NSE. Pancreatic mass biopsy

Pheochromocytoma adrenal medulla

Ten-year-old boy with headaches, tachycardia, and an abdominal mass. Adrenal gland biopsy

Pulmonary interstitial glycogenosis

Myxopapillary ependymoma

Lung biopsy from a 1-month-old infant who has severe respiratory distress and needs oxygen supplementation

CASE 78

History

Twelve-year-old girl with a sharply circumscribed, enhancing lesion in the filum terminale of the spinal cord. GFAP was positive and CK was negative in tumor cells. Tumor biopsy

Plexiform fibrohistiocytic tumor

Twelve-year-old girl with multinodular poorly circumscribed subcutaneous mass on the foot. Biopsy from the mass

Coccidioides immites infection lung

Five-year-old HIV positive immunosuppressed boy who is a resident of Arizona and presented with a granulomatous lesion in left lung

Sertoli-Leydig cell tumor ovary

Ovotestis

CASE 82

History

A 1.5-year-old girl with a 1 cm nodular mass in the right inguinal region. Biopsy is from the tissue labeled as “right gonad”

Fourteen-year-old girl with primary amenorrhea and pelvic pain. Neoplastic cells are positive for inhibin and calretinin. Ovarian tumor biopsy

Yolk sac tumor

Five-year-old girl with abdominal pain and rapidly growing abdominal mass. Serum AFP levels were high. Ovarian mass was resected, and it showed a variegated solid-cystic cut surface with zones of necrosis

Wilms tumor (favorable histology)

Four-year-old girl with a large abdominal mass. The right kidney was resected, and it showed a large solid yellow-colored mass replacing the entire kidney

Wilms tumor with diffuse anaplasia (unfavorable histology)

Three-year-old girl with enlarged right kidney. She has a past history of known Wilms tumor of left kidney. Section is from the right kidney tumor

Subependymal giant cell astrocytoma

Six-year-old boy with a history of tuberous sclerosis presented with a mass in the third ventricle of the brain. Brain tumor biopsy

Giant cell tumor of tendon sheath

Fourteen-year-old boy with a mass in right popliteal fossa. Biopsy is from the mass

Alveolar rhabdomyosarcoma

Seven-year-old girl with an enlarging soft-tissue mass in the heel of left foot. FISH studies show PAX3-FOXO1 gene rearrangements. Biopsy is from the mass

Acute myeloid leukemia-bone marrow

Six-year-old girl with generalized weakness, weight loss, and fever for 1 week. Bone marrow biopsy/aspirate was performed. Flow cytometry confirmed expression of cD11b, CD11c, CD13, CD33, HLA-DR, myeloperoxidase, and CD163

Carcinoid tumor-appendix

Eight-year-old boy who underwent appendectomy for appendicitis. At the time of surgery an incidental 1 cm yellow circumscribed mass was found on tip of the appendix. Tumor cells express chromogranin and are negative for CEA

Seminoma

Five-year-old boy with a painful testicular enlargement. Testicular tumor biopsy was performed and tumor cells were seen to express CD117, OCT4, and PLAP

Malignant melanoma of soft parts

Twelve-year-old boy with a deep soft-tissue mass in thigh. Tumor biopsy

Clear cell sarcoma of kidney

Eight-year-old boy with large mass in left kidney. The kidney was resected, and it showed a large gray-white solid tumorous mass. The tumor had also metastasized to the pelvic bone

Diffuse large B-cell lymphoma

Cervical lymph node biopsy from a 14-year-old boy with anemia and weight loss. Lesional cells expressed CD19, CD20 and light chain restriction. The cells did not express CD10 or TdT

Embryonal carcinoma of testis

Testicular resection for tumorous mass in a 8-year-old boy. Tumor cells expressed CK, CD30, and OCT4 but not EMA

Ependymoma

Large tumor in the posterior fossa of the brain in a 5-year-old girl presenting with headaches. Tumor cells expressed GFAP and EMA

Hemophagocytic lymphohistiocytosis

Bone marrow biopsy/aspirate in a 5-year-old boy who presented with fever, increased serum ferritin, abnormal liver function tests, and weakness

T-cell lymphoblastic lymphoma of mediastinum

Twelve-year-old boy who presented with a large mediastinal mass, dyspnea, and superior vena cava syndrome. Biopsy from the mass

Gastrointestinal stromal tumor (epithelioid variant)

Ten-year-old girl presented with a large mass in the wall of small bowel. Tumor cells are positive for c-Kit, vimentin, and CD34

Spitz nevus (spindle and epithelioid cell nevus)

Eight-year-old boy with a tan-colored papular mass (1 cm) on the cheek

Scleroderma (morphea)

Inflammatory myofibroblastic tumor

Nine-year-old girl with history of autoimmune disorders now presented with atrophic, hypopigmented patchy skin lesion on the genitalia

CASE 102

History

Seven-year-old boy with tumor of urinary bladder. The resected mass showed spindle cells that were positive for smooth muscle actin stain and AlK1. Several lymphocytes and plasma cells were admixed

Spitzoid malignant melanoma

Seven-year-old girl with a sudden enlargement in size of a skin lesion on forearm. The lesion is painful, irregular in shape, and 1.8 cm in size

Perilobar nephrogenic rests

Cutaneous mastocytosis

Biopsy from the right kidney of a 2-year-old boy who had the left kidney resected for a tumorous mass 1 year ago

CASE 105

History

Five-year-old boy with erythematous macules and telangiectasia in the legs. Lesional cells are positive for CD117 and toluidine blue

Hepatocellular carcinoma-fibrolamellar variant

Fibroma of heart

Fifteen-year-old boy with a large abdominal mass. Tumor cells express HepPar and Ck7. Liver biopsy

CASE 107

History

Seven-year-old boy with a cardiac mass that resulted in fatal ventricular arrhythmia. Tumor cells were positive for vimentin

Medulloepithelioma

Osteoblastoma

Eight-year-old girl with a tumorous mass arising in the ciliary body of the eye

CASE 109

History

Eleven-year-old girl with a 3 cm painful mass in base of the skull. On imaging, the mass was well demarcated and had a central nidus

Castleman disease-hyaline vascular variant

Sixteen-year-old girl with supraclavicular lymphadenopathy

Normal glomerulus

Twelve-year-old girl who died in a motor vehicle accident. Kidney biopsy

Focal segmental glomerulosclerosis

Five-year-old African American boy who presented with proteinuria, hematuria, hypertension, and edema. Electron microscopy (EM) showed extensive foot process effacement with epithelial cell vacuolization and often separation of the epithelial cells from underlying glomerular basement membrane

Minimal change glomerulopathy

Eleven-year-old girl with severe edema, heavy albuminuria, hypoalbuminemia, elevated serum cholesterol but no hematuria or hypertension. EM shows diffuse effacement of the foot processes. There are no electron-dense deposits

Cyclosporine/tacrolimus related nephrotoxicity

Eight-year-old girl who was a recipient of allogenic renal transplant for end-stage kidney failure. She was given anti-rejection therapy to prevent acute cellular rejection

Membranous glomerulonephritis

Insidious onset of nephrotic syndrome in a 15-year-old girl with hepatitis B-associated chronic hepatitis. IF shows confluent granular deposits of IgG and C3 along glomerular capillary loops. EM shows subepithelial electron dense deposits and fusion of epithelial foot processes