10. Pathology and Oncology MCQs

A 24-year-old male presents with a painless, firm nodule on the palmar aspect of his hand. It was previously excised as a 'ganglion cyst' but rapidly recurred. Biopsy reveals a nodular proliferation of polygonal cells with central necrosis, mimicking a granuloma. Immunohistochemistry is positive for cytokeratin and EMA, but negative for INI1. Which of the following is a classic characteristic of this tumor?

A 30-year-old female presents with a deep soft tissue mass in her foot. Biopsy shows uniform plump spindle cells in nests separated by fibrous septa. Immunohistochemistry is positive for S100 and HMB45. Which of the following translocations is characteristic of this diagnosis?

A 40-year-old male complains of progressive hip stiffness and mechanical catching. A radiograph reveals multiple calcified bodies of uniform size within the joint space.

What is the primary underlying pathophysiology of this condition?

A 35-year-old female presents with a recurrent, painless, monoarticular knee effusion. MRI demonstrates a large joint effusion and nodular synovial proliferation with prominent 'blooming artifact' on gradient-echo sequences. What genetic alteration primarily drives this condition?

A 22-year-old female presents with a slow-growing, painless mass in her deep anterior thigh. Staging CT reveals multiple asymptomatic pulmonary nodules, and a brain MRI reveals a solitary metastasis. Histology shows large polygonal cells in a pseudoalveolar pattern with PAS-positive, diastase-resistant crystalline inclusions. Which molecular finding is expected?

A 60-year-old male undergoes a core biopsy of a deep 12 cm painless thigh mass. Pathology reveals mature adipose tissue with scattered atypical hyperchromatic stromal cells. What molecular test is most specific to differentiate this atypical lipomatous tumor from a benign lipoma?

A 45-year-old female presents with right thigh pain. Radiographs demonstrate a 'ground-glass' lytic lesion in the proximal femur with varus bowing. MRI of the thigh incidentally reveals multiple well-circumscribed intramuscular masses showing bright T2 hyperintensity. The intramuscular masses most likely represent:

A 14-year-old male presents with a rapidly enlarging soft tissue mass in his forearm. Biopsy reveals small round blue cells. Cytogenetic testing confirms a t(2;13) translocation. Which fusion protein is pathognomonic for this diagnosis?

A 7-year-old female presents with precocious puberty, cafe-au-lait spots with irregular 'coast of Maine' borders, and an antalgic gait. Radiographs show a large, expansile lytic lesion in the proximal femur. This syndrome is caused by a somatic, post-zygotic activating mutation in which gene?

A 65-year-old female presents with a rapidly enlarging, painless 10 cm mass in her proximal thigh. Core needle biopsy reveals highly pleomorphic spindle cells in a storiform pattern with numerous atypical mitoses. Immunohistochemistry is completely negative for cytokeratin, S100, desmin, and SMA. What is the most likely diagnosis?

A 24-year-old male presents with a painless, slow-growing nodule on his right palm. Excisional biopsy demonstrates a granuloma-like architecture with central necrosis surrounded by atypical epithelioid cells. Immunohistochemistry reveals loss of SMARCB1 (INI1) expression. What is the most common pattern of metastasis for this lesion?

A 28-year-old female presents with a deep, highly vascular mass in her right thigh. Staging workup reveals asymptomatic brain metastases. Cytogenetic testing identifies a t(X;17)(p11;q25) translocation. What is the diagnosis?

A 32-year-old male presents with a mass intimately associated with his Achilles tendon. Histology shows nested cells with prominent nucleoli. The tumor cells stain strongly positive for S100 and HMB-45. Which of the following translocations is most characteristic?

A 29-year-old pregnant female presents with a rapidly enlarging, firm mass in her anterior abdominal wall. Biopsy shows spindle cells arranged in broad, sweeping fascicles without malignant nuclear features. Nuclear beta-catenin staining is positive. What is the most appropriate initial management?

A 65-year-old man presents with a large retroperitoneal mass. Biopsy demonstrates areas of well-differentiated adipocytic proliferation transitioning abruptly into a high-grade, non-lipogenic sarcoma. Amplification of which of the following genes on chromosome 12q13-15 is a hallmark of this disease?

An 80-year-old female presents with a rapidly growing, deep soft tissue mass in her proximal thigh.

Histology reveals a storiform pattern of highly pleomorphic, bizarre, multinucleated giant cells with frequent mitoses and areas of necrosis. Extensive immunohistochemical staining is negative for specific lineage markers. What is the most likely diagnosis?

A 6-year-old boy presents with a rapidly enlarging mass in his forearm. Histologic examination demonstrates small round blue cells with interspersed rhabdomyoblasts. Molecular testing is positive for a t(2;13) translocation. Which fusion gene product is responsible for this condition?

A 35-year-old male presents with a multi-nodular, firm cutaneous plaque on his trunk. Biopsy reveals a uniform spindle cell proliferation arranged in a prominent storiform ("cartwheel") pattern that infiltrates subcutaneous fat in a honeycomb appearance. Tumor cells strongly express CD34. What targeted systemic therapy can be utilized for unresectable or metastatic disease?

A 42-year-old female with numerous cafe-au-lait spots and cutaneous neurofibromas presents with sudden, rapid enlargement and severe pain in a long-standing thigh mass.

A biopsy confirms malignant transformation. What underlying genetic syndrome is the primary risk factor for this transformation?

A 30-year-old female presents with chronic knee swelling, catching, and brown synovial fluid on aspiration. MRI shows a joint effusion and nodular synovial thickening with "blooming artifact" on gradient-echo sequences. What specific molecular target is implicated in the pathogenesis of this disease?