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10. Pathology and Oncology MCQs

Practice Set 181 of 351

This practice set contains high-yield board review questions covering key concepts in 10. Pathology and Oncology. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 3601

Topic: 10. Pathology and Oncology

An 8-year-old boy is diagnosed with a solitary, painful eosinophilic granuloma of the clavicle confirmed by core needle biopsy. The lesion is structurally sound without an impending risk of fracture. What is the most appropriate next step in management?

. Wide surgical resection and allograft reconstruction
. Intralesional corticosteroid injection
. Multi-agent systemic chemotherapy
. External beam radiation therapy
. Radical claviculectomy

Correct Answer & Explanation

. Intralesional corticosteroid injection

Explanation

For a symptomatic, structurally stable solitary eosinophilic granuloma (LCH), minimally invasive treatments are preferred. Intralesional corticosteroid injection is highly effective at relieving pain and promoting lesion healing without the morbidity of surgical resection.

Question 3602

Topic: 10. Pathology and Oncology

A biopsy of a solitary lytic skull lesion in a 5-year-old child demonstrates cells containing 'tennis-racket' shaped Birbeck granules on electron microscopy. Immunohistochemical staining of these cells will be characteristically positive for which of the following?

. CD34 and Vimentin
. S-100 and CD1a
. CD68 and TRAP
. Cytokeratin and EMA
. SMA and Desmin

Correct Answer & Explanation

. S-100 and CD1a

Explanation

Langerhans Cell Histiocytosis (LCH) is characterized by the presence of Birbeck granules on electron microscopy. The pathological Langerhans cells characteristically stain positive for S-100, CD1a, and CD207 (langerin).

Question 3603

Topic: 10. Pathology and Oncology

A 7-year-old boy presents with a painful, lytic lesion in the proximal femur with periosteal reaction. Biopsy reveals cells with characteristic "coffee bean" grooved nuclei and electron microscopy demonstrates Birbeck granules. Which of the following immunohistochemical marker profiles is most specific for this diagnosis?

. CD34 and Smooth Muscle Actin (SMA) positive
. CD1a, S100, and Langerin (CD207) positive
. Cytokeratin and Epithelial Membrane Antigen (EMA) positive
. Desmin and MyoD1 positive
. CD99 and FLI-1 positive

Correct Answer & Explanation

. CD1a, S100, and Langerin (CD207) positive

Explanation

The clinical and histologic findings describe Langerhans Cell Histiocytosis (LCH). The neoplastic cells in LCH characteristically stain positive for CD1a, S100, and Langerin (CD207).

Question 3604

Topic: 10. Pathology and Oncology

A 4-year-old girl is evaluated for a skull mass. Radiographs reveal a lytic lesion with a "beveled edge" or "hole-within-a-hole" appearance. Which of the following is the most likely diagnosis?

. Langerhans Cell Histiocytosis
. Ewing Sarcoma
. Osteosarcoma
. Multiple Myeloma
. Metastatic Neuroblastoma

Correct Answer & Explanation

. Langerhans Cell Histiocytosis

Explanation

The "beveled edge" or "hole-within-a-hole" appearance on a skull radiograph is classic for Langerhans Cell Histiocytosis (Eosinophilic Granuloma). This occurs due to unequal destruction of the inner and outer tables of the skull.

Question 3605

Topic: 10. Pathology and Oncology

A 55-year-old female with systemic sclerosis desires surgical correction of severe proximal interphalangeal (PIP) joint flexion contractures in her hands to improve hygiene. What is the most significant perioperative risk that must be extensively discussed with this patient?

. Accelerated systemic spread of the disease
. Malignant hyperthermia during general anesthesia
. Digital ischemia and catastrophic wound healing failure
. Heterotopic ossification of the PIP joints
. Iatrogenic rupture of the extensor tendons

Correct Answer & Explanation

. Digital ischemia and catastrophic wound healing failure

Explanation

Patients with systemic sclerosis have profound digital microangiopathy. Any surgical intervention on the digits carries an extremely high risk of postoperative digital ischemia, necrosis, and severe wound healing complications.

Question 3606

Topic: 10. Pathology and Oncology

A 9-year-old boy presents with localized pain in his clavicle. Imaging reveals a solitary, well-circumscribed, 'punched-out' lytic lesion. Biopsy confirms Eosinophilic Granuloma. If the lesion remains symptomatic despite brief observation, what is the most appropriate first-line intervention?

. Wide en bloc resection and allograft reconstruction
. Systemic administration of methotrexate and cytarabine
. Radiation therapy
. Radical amputation
. Intralesional injection of methylprednisolone

Correct Answer & Explanation

. Intralesional injection of methylprednisolone

Explanation

Symptomatic, solitary Eosinophilic Granuloma (LCH) bone lesions that do not resolve with observation are effectively treated with intralesional corticosteroid (methylprednisolone) injection. Wide resection or radiation is overly aggressive for this benign condition.

Question 3607

Topic: 10. Pathology and Oncology

A 6-year-old boy presents with a painful, isolated lytic lesion in the clavicle with mild periosteal reaction. Biopsy confirms eosinophilic granuloma. There is no impending fracture or neurological deficit. What is the most appropriate initial management?

. En bloc wide resection
. Systemic chemotherapy
. Radiation therapy
. Observation and symptomatic management
. Preoperative embolization followed by curettage

Correct Answer & Explanation

. Observation and symptomatic management

Explanation

Isolated eosinophilic granuloma (LCH of bone) in children is a benign, often self-limiting process. Asymptomatic or mildly symptomatic lesions without high risk of pathologic fracture are typically managed with observation or intralesional corticosteroid injection.

Question 3608

Topic: 10. Pathology and Oncology

A patient with advanced systemic sclerosis is scheduled to undergo an elective orthopedic procedure. The surgical team must be hypervigilant regarding which of the following perioperative complications directly related to the disease pathophysiology?

. Massive perioperative hemorrhage due to primary thrombocytopenia
. Severe digital ischemia and necrosis secondary to extreme vasospasm
. Hypercalcemic crisis from mobilization of calcinosis cutis
. Acute adrenal insufficiency requiring stress-dose steroids
. Malignant hyperthermia

Correct Answer & Explanation

. Severe digital ischemia and necrosis secondary to extreme vasospasm

Explanation

Patients with systemic sclerosis suffer from severe microvascular disease and Raynaud's phenomenon. Perioperative stress, cold exposure, or the use of epinephrine-containing local anesthetics can precipitate severe vasospasm leading to digital ischemia or necrosis.

Question 3609

Topic: 10. Pathology and Oncology

A 6-year-old child presents with back pain and a normal neurologic examination. Radiographs of the thoracic spine demonstrate a severe, uniform collapse of the T7 vertebral body, with preservation of the adjacent disc spaces. Which of the following is the most likely diagnosis?

. Ewing sarcoma
. Osteosarcoma
. Langerhans cell histiocytosis
. Tuberculous spondylodiscitis
. Aneurysmal bone cyst

Correct Answer & Explanation

. Langerhans cell histiocytosis

Explanation

A severely flattened vertebral body (vertebra plana) with intact adjacent disc spaces in a child is the classic radiographic presentation of eosinophilic granuloma. This is a localized form of Langerhans cell histiocytosis.

Question 3610

Topic: 10. Pathology and Oncology

A biopsy of a lytic skull lesion in a 5-year-old boy reveals clusters of histiocytes with abundant eosinophilic cytoplasm and indented nuclei. On electron microscopy, rod-like intracytoplasmic inclusion bodies with a central striated line are identified. What are these structures called?

. Weibel-Palade bodies
. Russell bodies
. Birbeck granules
. Cowdry type A inclusions
. Howell-Jolly bodies

Correct Answer & Explanation

. Birbeck granules

Explanation

Birbeck granules are the hallmark electron microscopic finding in Langerhans cell histiocytosis. They are frequently described as "tennis-racket" shaped intracytoplasmic organelles.

Question 3611

Topic: 10. Pathology and Oncology

A 9-year-old boy has a biopsy of a solitary lytic clavicle lesion. Electron microscopy of the specimen demonstrates characteristic cytoplasmic organelles resembling "tennis rackets." These structures are pathognomonic for which of the following conditions?

. Ewing sarcoma
. Osteosarcoma
. Langerhans cell histiocytosis
. Chondroblastoma
. Fibrous dysplasia

Correct Answer & Explanation

. Langerhans cell histiocytosis

Explanation

Birbeck granules are characteristic cytoplasmic organelles shaped like tennis rackets seen on electron microscopy. They are pathognomonic for Langerhans cell histiocytosis (LCH).

Question 3612

Topic: Bone Tumors

A 40-year-old female with diffuse systemic sclerosis presents with palpable grating over the flexor tendons of her wrists and ankles during active motion. The presence of these tendon friction rubs is most strongly associated with an increased risk for which of the following?

. Progression to limited cutaneous sclerosis
. Development of osteosarcoma
. Severe internal organ involvement and reduced survival
. Avascular necrosis of the femoral head
. Acute septic arthritis

Correct Answer & Explanation

. Severe internal organ involvement and reduced survival

Explanation

Tendon friction rubs are highly specific to the diffuse cutaneous form of systemic sclerosis. Their presence is a poor prognostic marker, strongly associated with severe skin thickening, restrictive lung disease, renal crisis, and reduced overall survival.

Question 3613

Topic: 10. Pathology and Oncology

In a patient diagnosed with Hereditary Multiple Exostoses (HME), which clinical finding is considered a 'red flag' for malignant transformation into secondary chondrosarcoma after skeletal maturity?

. A cartilage cap thickness of 0.5 cm on MRI
. Presence of a pedunculated lesion pointing away from the joint
. New onset of pain and rapid growth of a lesion in adulthood
. Symmetrical involvement of the distal radius and ulna
. The presence of a sessile lesion in a 10-year-old

Correct Answer & Explanation

. New onset of pain and rapid growth of a lesion in adulthood

Explanation

Correct Answer: CMalignant transformation in HME occurs in approximately 1-5% of cases. Signs of malignancy include new onset of pain after skeletal maturity, rapid growth, and a cartilage cap thickness exceeding 1.5 to 2 cm in adults. Lesions pointing away from the joint are typical of benign osteochondromas.

Question 3614

Topic: Bone Tumors
A 22-year-old female presents with multiple enchondromas localized primarily to the left side of her body, including the hand and femur. There are no associated soft tissue hemangiomas. What is the most likely diagnosis?
. Maffucci Syndrome
. McCune-Albright Syndrome
. Ollier's Disease
. Trevor's Disease
. Jaffé-Campanacci Syndrome

Correct Answer & Explanation

. Ollier's Disease

Explanation

Ollier's disease (enchondromatosis) is characterized by multiple enchondromas, often with a unilateral or asymmetrical distribution. Unlike Maffucci syndrome, it does not involve soft tissue hemangiomas. It is a non-hereditary condition resulting from somatic mutations.

Question 3615

Topic: Bone Tumors

Which of the following conditions carries the highest lifetime risk (approaching 100% in some series) for the development of both skeletal and extra-skeletal malignancies, including visceral carcinomas?

. Monostotic Fibrous Dysplasia
. Ollier's Disease
. Maffucci Syndrome
. Hereditary Multiple Exostoses
. Dysplasia Epiphysealis Hemimelica

Correct Answer & Explanation

. Maffucci Syndrome

Explanation

Correct Answer: CMaffucci syndrome (Enchondromatosis plus hemangiomas) carries a significantly higher risk of malignancy than Ollier's disease. Patients have a very high risk of chondrosarcoma and are also predisposed to visceral malignancies such as gliomas and ovarian carcinomas.

Question 3616

Topic: Bone Tumors
A 9-year-old girl presents with a 'Shepherd's crook' deformity of the proximal femur and large, irregular café-au-lait spots with 'Coast of Maine' borders. Which molecular defect is responsible for this condition?
. Mutation in the COL1A1 gene
. Constitutive activation of the GNAS gene
. Inactivation of the EXT2 gene
. Deficiency of Alkaline Phosphatase
. Mutation in the FGFR3 gene

Correct Answer & Explanation

. Constitutive activation of the GNAS gene

Explanation

The patient has McCune-Albright syndrome (polyostotic fibrous dysplasia, café-au-lait spots, and precocious puberty). This is caused by a post-zygotic somatic mutation in the GNAS gene, leading to constitutive activation of the alpha subunit of the stimulatory G-protein (Gs-alpha) and increased intracellular cAMP.

Question 3617

Topic: Bone Tumors

Radiographic evaluation of a 15-year-old's femur shows a well-circumscribed intramedullary lesion with a 'ground-glass' appearance and a thin sclerotic rim (rind sign). What is the most appropriate initial management for an asymptomatic monostotic lesion in this location?

. Immediate wide resection and endoprosthetic replacement
. Curettage and autologous bone grafting
. Observation with serial radiographs
. High-dose radiation therapy
. Systemic chemotherapy

Correct Answer & Explanation

. Observation with serial radiographs

Explanation

Correct Answer: CAsymptomatic monostotic Fibrous Dysplasia (FD) often does not require surgical intervention and can be managed with observation. Surgery (curettage, grafting, or stabilization) is reserved for lesions that are symptomatic, causing significant deformity, or at high risk of pathological fracture.

Question 3618

Topic: 10. Pathology and Oncology

A patient with polyostotic fibrous dysplasia is found to have multiple soft tissue myxomas. This clinical association is known as:

. Proteus Syndrome
. Mazabraud Syndrome
. Albright's Hereditary Osteodystrophy
. Paget's Disease
. Gardner Syndrome

Correct Answer & Explanation

. Mazabraud Syndrome

Explanation

Correct Answer: BMazabraud syndrome is the rare association of fibrous dysplasia (usually polyostotic) and multiple soft tissue myxomas. These patients require monitoring for both skeletal complications and the potential for malignant transformation of the FD lesions.

Question 3619

Topic: 10. Pathology and Oncology

Dysplasia Epiphysealis Hemimelica (Trevor's Disease) is histologically indistinguishable from which of the following tumors?

. Enchondroma
. Osteoid Osteoma
. Osteochondroma
. Chondroblastoma
. Osteosarcoma

Correct Answer & Explanation

. Osteochondroma

Explanation

Correct Answer: CTrevor's disease is essentially an osteochondroma arising from the epiphysis (epiphyseal overgrowth). Histologically, it shows a benign osteocartilaginous cap similar to a standard osteochondroma, but its location is intra-articular or peri-articular at the epiphysis.

Question 3620

Topic: Bone Tumors

In the surgical management of a 'Shepherd's crook' deformity in a patient with Fibrous Dysplasia, which of the following is the preferred method of fixation to prevent recurrence of the deformity?

. Isolated Cortical Bone Grafting
. Compression Hip Screw (CHS)
. Intramedullary Nailing (e.g., Cephalomedullary nail)
. External Fixation
. Plate and Screw fixation only

Correct Answer & Explanation

. Intramedullary Nailing (e.g., Cephalomedullary nail)

Explanation

Correct Answer: CFor the Shepherd's crook deformity in Fibrous Dysplasia, intramedullary fixation is preferred over plates or bone grafts alone. Intramedullary devices provide better load-sharing and support the entire weakened femoral shaft, reducing the high rate of deformity recurrence seen with other methods.

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