Connective Tissue Neoplasms – Fibrous & Fibrohistiocytic Tumors

One-hundred question-and-answer flashcards summarizing key facts about fibrous and fibrohistiocytic connective-tissue neoplasms for exam review.

Fibrous, fibrohistiocytic, vascular, neural, muscle, and fat neoplasms.

What are the six major categories of connective tissue neoplasms outlined in the lecture?

Name eight fibrous neoplasms discussed.

Solitary fibrous tumor, myxoma, nasopharyngeal angiofibroma, nodular fasciitis, myofibroblastic tumors, fibromatosis, fibrosarcoma, and synovial sarcoma.

Where was the solitary fibrous tumor first described?

As a tumor of the pleura.

What is the cell of origin for solitary fibrous tumor believed to be?

Probable fibroblastic origin.

In the oral cavity, what is the usual presentation of a solitary fibrous tumor?

A submucosal mass in adults, most often on the buccal mucosa.

Does solitary fibrous tumor have malignant potential?

No, it is considered benign with no malignant potential.

Histopathologically, how is a solitary fibrous tumor characterized?

A well-circumscribed lesion composed of a patternless proliferation of spindle cells.

What is the treatment of choice for solitary fibrous tumor?

Surgical excision.

What material predominates in a myxoma?

Gelatinous myxoid material.

How common are oral myxomas?

They are rare.

What is the typical clinical presentation of an oral soft tissue myxoma?

A slow-growing, asymptomatic submucosal mass.

Which intraoral site is preferred by soft tissue myxoma?

The palate.

Describe the histopathology of myxoma.

Non-encapsulated lesion infiltrating surrounding tissue, with dispersed stellate and spindle fibroblasts in loose myxoid stroma.

What is the common recurrence rate after myxoma excision?

Recurrence is rare.

Nasopharyngeal angiofibroma most commonly affects which patient group?

Males in their second decade of life.

List the classic triad of symptoms for nasopharyngeal angiofibroma.

Epistaxis, nasal obstruction, and a mass within the nasopharynx.

How does nasopharyngeal angiofibroma appear intraorally?

As palatal expansion or inferior displacement of the soft palate with a blue color due to intense vascularity.

What is the histopathologic appearance of nasopharyngeal angiofibroma?

A mature, well-collagenized lesion containing cleft-like vascular channels.

What is the preferred management for nasopharyngeal angiofibroma?

Surgical removal, though recurrences are common.

Where was giant cell angiofibroma first described?

In the orbit.

Name four other sites where giant cell angiofibroma can occur.

Submandibular region, parascapular area, posterior mediastinum, and oral cavity.

Clinically, how does giant cell angiofibroma present?

As a slowly growing nodule or mass with normal overlying mucosa.

Histopathologically, what distinctive cells are found in giant cell angiofibroma?

Multinucleated floret-type giant cells among spindle cells.

What type of growth pattern does giant cell angiofibroma show microscopically?

Non-infiltrative patternless proliferation of round to spindle cells with collagen or myxoid stroma and pseudovascular spaces.

What is the usual treatment for giant cell angiofibroma?

Local excision.

What is another name for nodular fasciitis?

Pseudosarcomatous fasciitis.

What is the suspected etiologic factor sometimes linked to nodular fasciitis?

Trauma.

Describe the growth behavior of nodular fasciitis.

Rapid growth often accompanied by pain or tenderness.

In which age group is nodular fasciitis most common?

Young adults and adults.

Which body regions most commonly develop nodular fasciitis?

Trunk and extremities.

What percentage of nodular fasciitis cases arise in the head and neck?

About 10%.

Histologically, how are the fibroblasts arranged in nodular fasciitis?

Plump fibroblasts with vesicular nuclei arranged haphazardly to storiform.

What is the typical management of nodular fasciitis?

Conservative surgical excision.

Do nodular fasciitis lesions often recur?

Recurrence is rare.

What cell type proliferates in myofibroblastic tumors?

Myofibroblasts.

Name the two clinical forms of myofibroblastic tumors.

Myofibromatosis (multifocal) and myofibromas (solitary).

In which age group does myofibromatosis typically occur?

Infants.

Are myofibromas restricted to a certain age?

No, they occur across a wide age range.

What is the usual growth behavior of myofibroblastic tumors?

Slowly growing, circumscribed masses.

Which anatomic site is most commonly affected by myofibroblastic tumors?

The oral cavity.

What immunohistochemical marker is typically positive in myofibroblastic tumors?

Smooth muscle actin.

Describe the borders of myofibroblastic tumors histologically.

Pushing, well-demarcated borders.

What is the standard therapy for myofibroblastic tumors?

Local excision.

How is fibromatosis defined?

A group of locally aggressive neoplasms that infiltrate, destroy, and recur but do not metastasize.

What are the two broad classifications of fibromatosis?

Superficial and deep (desmoid).

Name two types of superficial fibromatosis.

Palmar and plantar.

Do superficial fibromatoses occur in the oral cavity?

No.

List the three categories of deep (desmoid) fibromatosis.

Sporadic, familial adenomatous polyposis (FAP) associated, and multicentric (familial).

What percentage of desmoid fibromatosis cases are extra-abdominal?

About 60%.

Which desmoid fibromatosis subtype can occur in the oral cavity?

Extra-abdominal desmoid.

What is the intraoral site of predilection for extra-abdominal desmoid fibromatosis?

The mandible.

Describe the demographic profile for extra-abdominal desmoid fibromatosis.

Seen in children and young adults, more common in females.

Histologically, how does fibromatosis appear?

Non-encapsulated infiltrative lesion with fascicular growth of uniform fibroblasts surrounded by abundant collagen.

What is the recommended treatment for fibromatosis?

Aggressive surgical approach.

Does fibromatosis metastasize?

No, there is no metastatic potential.

Define fibrosarcoma.

A malignant spindle cell tumor of fibroblastic origin.

Historically, how was fibrosarcoma viewed among soft tissue sarcomas?

It was once considered the most common.

Is fibrosarcoma more of a metastatic or local problem?

Primarily locally destructive with less frequent metastasis.

Which age group is most commonly affected by fibrosarcoma?

Young adults.

How common is fibrosarcoma in the head and neck?

It is rare.

From which structures does fibrosarcoma of bone arise?

Periosteum, endosteum, or periodontal ligament.

Describe the classic histologic pattern of fibrosarcoma.

Malignant fibroblasts arranged in a herringbone or interlacing fascicular pattern.

What is the preferred treatment for fibrosarcoma?

Wide surgical excision.

What is the five-year survival rate for fibrosarcoma?

Approximately 30–50%.

Which two tumor types comprise fibrohistiocytic tumors?

Benign fibrous histiocytoma and malignant fibrous histiocytoma.

What is another term for malignant fibrous histiocytoma?

Pleomorphic undifferentiated sarcoma.

How do benign fibrous histiocytomas typically present?

As painless masses that may ulcerate, often in adults in their fifth decade.

Radiographically, how does a benign fibrous histiocytoma of bone appear?

As a radiolucency with an ill-defined margin.

Histologically, what growth pattern is characteristic of benign fibrous histiocytoma?

Storiform (cartwheel) pattern of spindle cells.

Does benign fibrous histiocytoma recur after complete excision?

No, it does not tend to recur.

List the five variants of malignant fibrous histiocytoma.

Pleomorphic-storiform, myxoid (myxofibrosarcoma), giant cell, inflammatory, and angiomatoid.

Which adult population is most affected by malignant fibrous histiocytoma?

Male adults.

Most malignant fibrous histiocytomas arise in which anatomical regions?

The extremities and retroperitoneum.

How common is malignant fibrous histiocytoma in the head and neck?

Rare.

When occurring in bone, is malignant fibrous histiocytoma more or less aggressive?

More aggressive with potential to recur and metastasize.

Describe the histologic features of malignant fibrous histiocytoma.

Proliferation of pleomorphic spindle cells with frequent mitoses, necrosis, and marked atypia.

What is the treatment of choice for malignant fibrous histiocytoma?

Wide surgical excision.

What recurrence rate is associated with malignant fibrous histiocytoma?

About 40%.

What is the five-year survival range for malignant fibrous histiocytoma?

20–60%.

Nodular fasciitis is considered benign despite its rapid growth—true or false?

True.

Which immunohistochemical marker helps distinguish myofibroblastic tumors from other fibrous lesions?

Smooth muscle actin positivity.

Giant cell angiofibroma shows infiltrative borders—true or false?

False; it exhibits non-infiltrative growth.

Which fibrous lesion is typically associated with epistaxis?

Nasopharyngeal angiofibroma.

In fibrosarcoma, metastasis is infrequent; name the most common local behavior.

Recurrence/local destructive infiltration.

What gender predominance is noted in extra-abdominal desmoid fibromatosis?

Female predominance.

Which lesion is also called pseudosarcomatous because it mimics cancer histologically?

Nodular fasciitis.

Recurrence is common in nasopharyngeal angiofibroma despite benign histology—true or false?

True.

Which tumor has multinucleated floret-type giant cells?

Giant cell angiofibroma.

Name one other myxoid lesion that myxoma might be confused with.

Nerve sheath myxoma (or oral focal mucinosis).

What growth pattern do fibroblasts form in benign fibrous histiocytoma?

Storiform/cartwheel/mat-like.

Which type of fibromatosis is associated with familial adenomatous polyposis?

Deep (desmoid) fibromatosis.

How are superficial fibromatoses different from deep desmoids regarding oral involvement?

Superficial fibromatoses do not occur in the oral cavity.

Which lesion often shows a blue coloration intraorally due to vascularity?

Nasopharyngeal angiofibroma.

What is the typical gender distribution for nodular fasciitis?

No gender predilection.

Which lesion was first described in the orbit and later found in the oral cavity?

Giant cell angiofibroma.

What is the main distinguishing histologic arrangement in fibrosarcoma compared to other spindle cell tumors?

Herringbone pattern.

Which spindle cell malignancy was historically the generic name for many high-grade sarcomas before immunohistochemistry?

Malignant fibrous histiocytoma.

What is the prognosis for nasopharyngeal angiofibroma regarding metastasis?

It does not metastasize but often recurs locally.

Which lesion may produce palatal expansion and inferior displacement of the soft palate?

Nasopharyngeal angiofibroma.

Why is aggressive surgery recommended for fibromatosis even though it lacks metastatic potential?

Because of its infiltrative, destructive behavior and high recurrence rate.