Bone and Soft Tissue Pathology — MCQs

Q: Fibrous histiocytoma is classified as which type of tumor?

Soft tissue tumor. ***Soft tissue tumor*** - Fibrous histiocytoma is a type of **soft tissue tumor** arising from fibroblasts and histiocytes [1]. - It typically presents as a **nodular mass** and can be mistaken for other spindle cell tumors. *Hemangiopericytoma* - This is a vascular tumor arising from **pericytes**, often presenting as a deep-seated mass rather than a fibrous nodule. - Hemangiopericytoma has a distinct morphology and is associated with **hemorrhagic pathology**, unlike fibrous histiocytoma. *Angiomyolipomas* - Composed of **blood vessels, smooth muscle, and fat**, angiomyolipomas typically occur in the kidneys, not resembling fibrous histiocytoma. - These tumors are often associated with **tuberous sclerosis**, which is not the case for fibrous histiocytoma. *Angiomyosarcoma* - This malignant tumor consists of malignant **vascular and smooth muscle** components, distinct from the benign nature of fibrous histiocytoma. - Angiomyosarcoma has a poor prognosis and is characterized by **aggressive behavior**, unlike the benign fibrous histiocytoma. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1222.

Q: The most common variety of soft tissue sarcoma is:

Liposarcoma. ***Liposarcoma*** - Currently considered the **most common soft tissue sarcoma** in adults, accounting for approximately **20-25% of all cases** [1]. - Arises from **adipose tissue** and has several subtypes including well-differentiated, dedifferentiated, myxoid, and pleomorphic variants [1][2]. *Rhabdomyosarcoma* - Primarily affects **children and adolescents**, representing the most common soft tissue sarcoma in pediatric population [4]. - Accounts for only **3-5% of all soft tissue sarcomas** when considering all age groups, making it less common overall. *Malignant fibrous histiocytoma* - This is an **outdated term** that has been largely replaced by **"undifferentiated pleomorphic sarcoma"** in current WHO classification. - While historically considered common, modern pathology recognizes it as a **diagnosis of exclusion** rather than a specific entity. *Synovial sarcoma* - Represents approximately **5-10% of all soft tissue sarcomas** [3], making it significantly less common than liposarcoma. - Characterized by specific **t(X;18) translocation** [3] and typically occurs near **joints and tendon sheaths** in young adults. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1222. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1222-1223. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1225-1226. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1224-1225.

Q: Most common tumor producing purely osteoclastic (osteolytic) metastases is?

Kidney. ***Kidney*** - **Renal cell carcinoma** is the most common tumor associated with **purely osteolytic (osteoclastic)** bone metastases [2]. - These metastases characteristically cause **bone destruction** through increased osteoclastic activity without any osteoblastic (bone-forming) component. - The metastases appear as **punched-out lytic lesions** on radiography. *Lung* - While lung cancer commonly metastasizes to bone and typically produces **predominantly lytic lesions**, it can show mixed patterns [1]. - **Small cell lung cancer** and **squamous cell carcinoma** of the lung cause osteolytic metastases, but not as characteristically pure as kidney cancer. *Prostate* - **Prostate cancer** is highly associated with **osteoblastic (bone-forming) metastases**, which are characterized by increased bone density [4]. - This pattern is the opposite of the purely osteolytic lesions seen in kidney cancer. *Thyroid* - **Follicular thyroid carcinoma** frequently metastasizes to bone and produces osteolytic lesions [3]. - However, kidney cancer (renal cell carcinoma) is more commonly recognized for producing **purely osteolytic** metastases. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 724-725. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 492-493. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 671-672. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 993-994.

Practice by Chapter

Bone Development and Growth

Practice Questions

Fracture Healing

Practice Questions

Osteomyelitis and Infectious Diseases

Practice Questions

Metabolic Bone Diseases

Practice Questions

Bone Tumors and Tumor-like Lesions

Practice Questions

Joints and Rheumatologic Diseases

Practice Questions

Soft Tissue Tumors

Practice Questions

Muscular Dystrophies and Myopathies

Practice Questions

Diseases of Tendons and Fascia

Practice Questions

Pathology of Orthopedic Implants

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Scan to download app