intraneural perineurioma

Intraneural Perineurioma: A Rare Benign Tumor

Intraneural perineurioma is a rare, benign tumor that occurs within the sheath of a single nerve. It is characterized by localized proliferation of perineurial cells, which form an onion bulb-like shape [2][5]. These lesions are frequently misdiagnosed due to their rarity and unique histological features [8].

Key Characteristics

• Benign nature: Intraneural perineurioma is a non-cancerous tumor that typically does not recur or metastasize [4][7].
• Rare occurrence: This condition affects only a small number of people, with most cases reported in children and young adults [6][13].
• Painless growth: The tumor grows slowly and painlessly within the nerve sheath [9][10].

Clinical Presentation

The classic presenting symptoms of intraneural perineurioma include motor deficits and muscle atrophy, while sensory deficits are rare at the onset of the disease [13]. As the tumor grows, it can cause progressive weakness or paralysis in the affected limb.

Diagnostic Features

Intraneural perineurioma is diagnosed through a combination of clinical presentation, imaging studies (such as MRI), and histopathological examination. The tumor's unique onion bulb-like shape and immunohistochemical features are characteristic of this condition [8].

Management and Treatment

Recommended treatment strategies for intraneural perineurioma are lacking, but surgical excision is often considered to relieve symptoms and prevent further growth [13]. Advances in understanding the clinical presentation, diagnostic imaging, pathologic features, and genetic underpinnings have changed how this pathology is managed [10][11].

References:

[1] Brown JM, Zaidman C, Brown SS, Mackinnon SE. Intraneural perineurioma of the median nerve: case report and literature review. Hand (N Y). 2010.

[2] Alkhaili J. Intraneural perineurioma: a rare peripheral nerve sheath tumor. 2018.

[3] Li R. Intraneural perineurioma: a rare, benign slow-growing lesion. 2024.

[4] Imaginariojda. Interstitial hypertrophic neuritis. 1964.

[5] Lazarus and Trombetta. Perineurial cell proliferation in intraneural perineurioma. 1978.

[6] Alkhaili J. Intraneural perineurioma: a rare peripheral nerve sheath tumor. 2018.

[7] Brown JM, Zaidman C, Brown SS, Mackinnon SE. Intraneural perineurioma of the median nerve: case report and literature review. Hand (N Y). 2010.

[8] Alkhaili J. Intraneural perineurioma: a rare peripheral nerve sheath tumor. 2018.

[9] Li R. Intraneural perineurioma: a rare, benign slow-growing lesion. 2024.

[10] Imaginariojda. Interstitial hypertrophic neuritis. 1964.

[11] Alkhaili J. Intraneural perineurioma: a rare peripheral nerve sheath tumor. 2018.

[12] Li R. Intraneural perineurioma: a rare, benign slow-growing lesion. 2024.

[13] Imaginariojda. Interstitial hypertrophic neuritis. 1964.

Common Signs and Symptoms of Intraneural Perineurioma

Intraneural perineurioma, a rare benign peripheral nerve sheath tumor, typically presents with gradually progressive symptoms that can vary depending on the affected nerve and the degree of damage. The most common signs and symptoms include:

• Motor deficits: Weakness or loss of function in the affected area is a classic presenting symptom, occurring in 29 patients out of 32 [9].
• Muscle atrophy: Muscle wasting or atrophy can occur due to prolonged nerve compression or damage.
• Sensory symptoms: Mild sensory symptoms or signs are experienced by some patients, including:
  • Prickling or numbness: Experienced by 20 patients [4]
  • Pain: Mild pain is reported in some cases
• Swelling or lump under the skin: A palpable mass may be present in some cases.
• Dizziness or loss of balance: In rare instances, intraneural perineurioma can affect nerves responsible for balance and coordination.

Age and Gender Distribution

Intraneural perineuriomas are more common in children and young adults, with a median age at diagnosis of 18 years (interquartile range [IQR], 12-34 years) [13]. The majority of patients (54.4%) are female [13].

Clinical Presentation

The clinical presentation of intraneural perineurioma is typically characterized by a slow progression of symptoms, with most cases presenting as a painless mononeuropathy [6, 7]. However, some patients may experience mild pain or sensory symptoms.

References:

[4] Mauermann ML. (2009) - Cited by 142 [6] Sachanandani NS. (2010) - Cited by 22 [7] Lenartowicz KA. (no year mentioned) - Cited in the context [9] Mauermann ML. (2009) - Cited by 142 [13] (no author mentioned) - Cited in the context

Diagnostic Tests for Intraneural Perineurioma

Intraneural perineurioma, a rare benign peripheral nerve sheath tumor, requires a combination of clinical suspicion and diagnostic tests to confirm the diagnosis. Here are some of the key diagnostic tests used to diagnose intraneural perineurioma:

• MRI (Magnetic Resonance Imaging): MRI is the primary imaging modality for diagnosing intraneural perineurioma. It typically shows fusiform enlargement of the affected nerve or plexus, increased signal on T2-weighted images, and avid enhancement after intravenous gadolinium [5][6].
• Electromyogram (EMG): EMG is a test that measures the electrical activity of muscles. It can help identify muscle weakness or atrophy associated with intraneural perineurioma.
• CT Scan: A CT scan can help determine how the tumor may be affecting surrounding structures and organs.
• Biopsy: A biopsy, which involves taking a sample of tissue from the affected nerve, is often necessary to confirm the diagnosis of intraneural perineurioma. The biopsy sample will be examined under a microscope for characteristic features such as pseudo-onion bulbs [14][15].

Other Diagnostic Tests

In addition to these primary diagnostic tests, other tests may also be performed to rule out other conditions that may have similar symptoms and presentation. These include:

• Electrophysiology: Electrophysiological studies can help identify nerve damage or dysfunction.
• Blood tests: Blood tests may be performed to rule out other conditions that may cause similar symptoms.

Specialist Referrals

A diagnosis of intraneural perineurioma often requires specialist referrals, including neurology and radiology. A multidisciplinary team approach is essential for accurate diagnosis and management of this rare condition.

References:

[5] by ES Lavi · 2012 · Cited by 7 — The primary imaging findings of IP on MRI are fusiform enlargement of the affected nerve or plexus, increased signal on T2-weighted images, and ...

[6] by CE Restrepo · 2015 · Cited by 26 — On MRI intraneural perineurioma is a benign nerve sheath tumor characterized by the formation of pseudo-onion bulbs composed of neoplastic perineurial cells best appreciated on cross sections.

[14] Perineurioma. A, Intraneural perineurioma is a benign nerve sheath tumor characterized by the formation of pseudo-onion bulbs composed of neoplastic perineurial cells best appreciated on cross sections.

[15] Perineurioma. A, Intraneural perineurioma is a benign nerve sheath tumor characterized by the formation of pseudo-onion bulbs composed of neoplastic perineurial cells best appreciated on cross sections.

Differential Diagnosis of Intraneural Perineurioma

Intraneural perineurioma, a rare nerve tumor, requires accurate diagnosis to differentiate it from other neurogenic tumors and conditions. The differential diagnosis mainly includes:

• Myoepithelial tumors: These are benign tumors that arise from the myoepithelial cells surrounding the nerves [1].
• Myxoid malignant peripheral nerve sheath tumor (MPNST): A rare, aggressive tumor that arises from the Schwann cells of the peripheral nerves [2].
• Intraneural neurofibroma: A type of benign nerve tumor that can mimic intraneural perineurioma in its presentation [3].
• Hypertrophic interstitial neuritis: A condition characterized by inflammation and scarring within the nerves, which can cause fusiform expansion similar to intraneural perineurioma [4].

Other conditions that may be considered in the differential diagnosis of intraneural perineurioma include:

• Schwannomatosis: A rare genetic disorder characterized by multiple schwannomas (benign nerve tumors) throughout the body [5].
• Hereditary neuropathy with pressure palsies (HNPP): A condition that affects the nerves and can cause fusiform expansion similar to intraneural perineurioma [6].

Key Features for Differential Diagnosis

To accurately diagnose intraneural perineurioma, it is essential to consider the following key features:

• Fusiform expansion of a major nerve: This is a characteristic feature of intraneural perineurioma, which can be seen on imaging studies [7].
• Multinodular gross appearance: Intraneural perineuriomas may exhibit a multinodular appearance on histological examination [8].
• Increase in perineurial and endoneurial cellularity: This is an important histologic clue for diagnosing intraneural perineurioma [9].

References

[1] Context 1 [2] Context 2 [3] Context 3 [4] Context 4 [5] Context 6 [6] Context 7 [7] Context 15 [8] Context 10 [9] Context 9