biology

Juvenile active ossifying fibroma

Juvenile active ossifying fibroma is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Juvenile active ossifying fibroma rather than just read about it. In short: A juvenile active ossifying fibroma is a benign fibro-osseous neoplasm composed of mixture of stroma and bone characterized by rapid and destructive growth. Classification This tumor has gone by several names in the past, but active ossifying fibroma is similar to juvenile active ossifying fibroma, except it does not develop in young patients.

Key takeaways

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Reference excerpt

A juvenile active ossifying fibroma is a benign fibro-osseous neoplasm composed of mixture of stroma and bone characterized by rapid and destructive growth.

Classification This tumor has gone by several names in the past, but active ossifying fibroma is similar to juvenile active ossifying fibroma, except it does not develop in young patients. Aggressive psammomatoid ossifying fibroma is still employed by some, but is to be discouraged.

Signs and symptoms Most patients are asymptomatic, and come to clinical attention when a mass is discovered incidentally on routine dental X-rays. When patients are symptomatic, they present with non-specific symptoms, such as chronic sinusitis, rhinorrhea, obstruction, pain, facial enlargement and possibly visual changes.

Imaging findings When performing imaging studies, bone windows in computed tomography studies are the best. The lesion is usually identified as a well demarcated, expansile mass with an ossified rim at the periphery. Calcifications are noted throughout. MRI shows a variable finding depending on T1 or T2 weighted images, dependent on the amount of bone to fibrous connective tissue ratio.

Pathology findings The tumors are described as "shelling out" by the surgeon, which gives a well-circumscribed, smooth surface of tan, white, firm-gritty material. The tumors range in size from a few millimeters up to 10 cm.

By microscopic evaluation, the tumors are composed of a variably cellular stroma make up of spindled to stellate fibroblast-like cells. Within this stroma, are numerous small, rounded, mineralized collagenous ossicles and immature osteoid. Many times the curved-shaped bone fragments have a collagenous rim around them. Ossicles may fuse to form much large mineralizations. Cementum-like psammomatous bodies (cementicles) may also be present. Osteoblastic rimming is not uncommon. Occasionally, giant cells and even mitoses are seen.

Differential diagnoses Active ossifying fibroma must be separated from fibrous dysplasia, cementoblastoma, and meningioma. This type of separation must be made with the aid of imaging studies, and should not be done by histology examination only.

Management It is important to get complete excision as early in the disease process as possible. Once the lesion is removed, the prognosis is excellent. However, if the lesion is incompletely excised, recurrences may be seen in up to 60% of patients. The recurrences are highest in sinus tumors.

Epidemiology This tumor is far less common than conventional ossifying fibroma, and is considered a rare tumor. Patients usually come to clinical attention when <15 years of age, but a wide age range (3 months to 70 years) can be affected. Both genders are affected equally, with the paranasal sinuses most commonly affected. Specifically, the ethmoid sinus is affected most often, followed by frontal sinus, maxillary sinus and sphenoid sinus. The maxilla is the second most common location after the paranasal sinuses, while the mandible and temporal bone are infrequently affected. This tumor does not frequently extracranial sites nor soft tissues sites.

References

Further reading Lester D. R. Thompson; Bruce M. Wenig (2011). Diagnostic Pathology: Head and Neck: Published by Amirsys. Hagerstown, MD: Lippincott Williams & Wilkins. pp. 6:60–1. ISBN 978-1-931884-61-7.

Illustrations

Worked examples

Example 1 — a first encounter with Juvenile active ossifying fibroma

Start with the simplest possible case. Write down what Juvenile active ossifying fibroma claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Juvenile active ossifying fibroma before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Juvenile active ossifying fibroma ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Juvenile active ossifying fibroma

In research: Juvenile active ossifying fibroma appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Juvenile active ossifying fibroma in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Juvenile active ossifying fibroma is common in secondary-school and first-year university syllabi. It links to neighbouring topics Anatomical pathology, Tumors, so understanding it makes those chapters shorter.
In everyday life: Look for Juvenile active ossifying fibroma outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Juvenile active ossifying fibroma in 20 minutes

Read the reference excerpt below once, without taking notes.
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Frequently asked questions

What is Juvenile active ossifying fibroma in simple terms?

A juvenile active ossifying fibroma is a benign fibro-osseous neoplasm composed of mixture of stroma and bone characterized by rapid and destructive growth. Classification This tumor has gone by several names in the past, but active ossifying fibroma is similar to juvenile active ossifying fibroma…

Why does Juvenile active ossifying fibroma matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Juvenile active ossifying fibroma?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Juvenile active ossifying fibroma.