science

Glomus tumor

Glomus tumor is a science 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 Glomus tumor rather than just read about it. In short: Glomus tumor was also the name formerly (and incorrectly) used for a tumor now called a paraganglioma. A glomus tumor (also known as a "solitary glomus tumor") is a rare neoplasm arising from the glomus body and mainly found under the nail, on the fingertip or in the foot.

Key takeaways

Glomus tumor belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Glomus tumor to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Glomus tumor from memory before moving on to harder problems.

Reference excerpt

Glomus tumor was also the name formerly (and incorrectly) used for a tumor now called a paraganglioma.

A glomus tumor (also known as a "solitary glomus tumor") is a rare neoplasm arising from the glomus body and mainly found under the nail, on the fingertip or in the foot. They account for less than 2% of all soft tissue tumors. The majority of glomus tumors are benign, but they can also show malignant features. Glomus tumors were first described by Hoyer in 1877 while the first complete clinical description was given by Masson in 1924. Histologically, glomus tumors are made up of an afferent arteriole, anastomotic vessel, and collecting venule. Glomus tumors are modified smooth muscle cells that control the thermoregulatory function of dermal glomus bodies. As stated above, these lesions should not be confused with paragangliomas, which were formerly also called glomus tumors in now-antiquated clinical usage. Paragangliomas do not arise from glomus cells, but glomus tumors do. Familial glomangiomas have been associated with a variety of deletions in the GLMN (glomulin) gene, and are inherited in an autosomal dominant manner, with incomplete penetrance.

Signs and symptoms Glomus tumors are usually solitary and small lesions. The vast majority are found in the hand, wrist, foot, and under the fingernails. They are often painful, and the pain is reproduced when the lesion is placed in cold water - a history of sensitivity to cold weather is also common. Multiple tumors are less likely to be painful. These tumors tend to have a bluish discoloration, although a whitish appearance may also be noted. Elevation of the nail bed can occur. In rare cases, the tumors may present in other body areas, such as the gastric antrum or glans penis. Treatment is essentially the same. Malignant glomus tumors, or glomangiosarcomas, are extremely rare and usually represent a locally infiltrative malignancy. However, metastases do occur and are usually fatal.

Diagnosis By histopathology, glomus tumors can be termed as follows:

Solid glomus tumor (75% of cases): Consisting predominantly of glomus cells, with poor vasculature and rare smooth muscle cells. Glomangioma (20% of cases): Tumors with a prominent vascular component. Glomangiomyoma (5% of cases): Tumors with prominent vascular and smooth muscle components. Cancerous glomus tumors are exceedingly rare. Criteria for the diagnosis of malignancy in glomus tumors are:

Tumor size of more than 2 centimeters and subfascial or visceral location. Atypical mitotic figures. Marked nuclear atypia and any level of mitotic activity. Pericytes of Zimmerman Cancerous glomus tumors have been subdivided into three categories based on their histologic appearance: locally infiltrative glomus tumors (LIGT), glomangiosarcomas arising in benign glomus tumors (GABG), and glomangiosarcomas arising de novo (GADN). A few cases of cancerous glomus tumors have been reported; however, they are usually only locally invasive, and metastases are exceedingly rare. There is one report of widespread metastases of a malignant glomus tumor involving the skin, lungs, jejunum, liver, spleen, and lymph nodes. Another report of a malignant glomus tumor (glomangiosarcoma) with metastases from the skin. A malignant glomus tumor one arose from the kidneys.

Differential The probable misdiagnosis of many of these lesions as hemangiomas or venous malformations also makes an accurate assessment of incidence difficult.

Treatment

Surgical excision is the preferred treatment for benign glomus tumors.

Epidemiology The exact rate of glomus tumors is unknown. The multiple variant is rare, accounting for less than 10% of all cases.

Sex Solitary glomus tumors, particularly subungual lesions, are more common in females than in males. Multiple lesions are slightly more common in males.

Age Solitary glomus tumors are more frequent in adults than in others. Multiple glomus tumors develop 11–15 years earlier than single lesions; about one third of the cases of multiple tumors occur in those younger than 20 years. Congenital glomus tumors are rare; they are plaguelike in appearance and are considered a variant of multiple glomus tumors.

See also Coccygeal glomus List of cutaneous conditions Myopericytoma

References

External links

synd/1584 at Whonamedit? 00314 at CHORUS

Illustrations

Worked examples

Example 1 — a first encounter with Glomus tumor

Start with the simplest possible case. Write down what Glomus tumor claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Glomus tumor 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 Glomus tumor 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 Glomus tumor

In research: Glomus tumor appears in science 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 Glomus tumor 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: Glomus tumor is common in secondary-school and first-year university syllabi. It links to neighbouring topics Dermal and subcutaneous growths, Soft tissue tumors, Types of neoplasia, so understanding it makes those chapters shorter.
In everyday life: Look for Glomus tumor 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 Glomus tumor in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Glomus tumor means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Glomus tumor out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Glomus tumor in simple terms?

Glomus tumor was also the name formerly (and incorrectly) used for a tumor now called a paraganglioma. A glomus tumor (also known as a "solitary glomus tumor") is a rare neoplasm arising from the glomus body and mainly found under the nail, on the fingertip or in the foot.

Why does Glomus tumor matter?

Because it connects several science 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 Glomus tumor?

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 Glomus tumor.