obsolete Lipomatous hamartoma

Lipomatous Hamartoma: A Rare Benign Tumor

A lipomatous hamartoma, also known as fibrolipomatous hamartoma or lipofibrohamartoma, is a rare benign tumor that affects the peripheral nerves. It is characterized by the infiltration of adipose and fibrous tissue into the epineurium and perineurium, causing enlargement of the nerve.

Clinical Presentation

The clinical presentation of lipomatous hamartoma can mimic carpal tunnel syndrome or other conditions affecting the median nerve. Symptoms may include numbness, tingling, or weakness in the affected area.

Types and Locations

Lipomatous hamartomas can affect any peripheral nerve, but they most frequently occur in the median nerve, inside the carpal tunnel. They are also known to be associated with hemihyperplasia-multiple lipomatosis syndrome, a rare genetic overgrowth syndrome.

Microscopic Description

The microscopic description of lipomatous hamartoma reveals infiltration of epineurium and perineurium by adipose and fibrous tissue (collagen), causing enlargement of the nerve. This condition is also known as fibrolipoma of nerve or macrodystrophia lipomatosa.

Epidemiology

Lipomatous hamartomas may be noted at birth, indicating a possible congenital origin. They are rare and benign tumors that require proper diagnosis and treatment to prevent complications.

References

• [1] Fibrolipomatous hamartoma is a rare benign slow growing fibrofatty tumor of peripheral nerves of unknown etiology.
• [4] Lipofibrohamartoma (LFH) is a rare pseudotumor which may affect any peripheral nerve. Its most frequent location is in the median nerve, inside the carpal tunnel.
• [10] Lipomatosis of nerve (LN, aka fibrolipomatous hamartoma or lipofibromatous hamartoma of nerve) is a benign overgrowth of perineural fibroadipose tissue that consists of infiltration of the epineurium and perineurium by adipose and fibrocollagenous tissue resulting in overall enlargement of the nerve.
• [12] Microscopic (histologic) description. Infiltration of epineurium and perineurium by adipose and fibrous tissue (collagen), causing enlargement of nerve ... Also called fibrolipoma of nerve, fibrolipomatous hamartoma of nerve, macrodystrophia lipomatosa
• [13] It has been reported in the literature with various descriptions, such as lipofibroma, intraneural lipoma, fatty infiltration of the median nerve, or lipomatous hamartoma.

Lipomatous Hamartoma: A Rare Tumor

A lipomatous hamartoma is a rare, benign tumor composed predominantly of adipose tissue.

Diagnostic Tests for Obsolete Lipomatous Hamartoma

Lipomatous hamartoma, a rare benign tumor, has been largely replaced by more advanced diagnostic tests. However, understanding the historical context and older diagnostic methods can provide valuable insights.

• X-ray: In the past, X-rays were used to diagnose lipomatous hamartomas, particularly in cases where the tumor had a "popcorn" like appearance (12). However, this method has low sensitivity (66%) for diagnosing endobronchial tumors (11).
• Ultrasound: Ultrasound was also used as a diagnostic tool, but its effectiveness is limited compared to modern imaging techniques.
• Chest X-ray: Chest X-rays may be unremarkable in patients with endobronchial hamartoma, making it necessary to use more advanced tests for further work-up (14).

Modern Diagnostic Tests

Fortunately, newer and more accurate diagnostic tests have replaced these older methods. These include:

• MRI: Magnetic Resonance Imaging (MRI) is now the diagnostic imaging test of choice for lipomatous hamartoma (2). It can specify the tumor's characteristics, such as its heterogeneous signal in T1 and high signal due to fat and cartilaginous components in T2.
• CT scan: Computed Tomography (CT) scans are also used to diagnose lipomatous hamartomas, particularly for detecting low-attenuation endobronchial masses (14).
• Diagnostic and therapeutic bronchoscopy: This test is now the preferred method for diagnosing and treating endobronchial hamartoma (14).

In summary, while older diagnostic tests like X-rays and ultrasound were once used to diagnose lipomatous hamartoma, they have been largely replaced by more advanced techniques like MRI and CT scans.

Based on the search results, it appears that there are some reports of successful treatment of lipofibromatous hamartoma (LFH) with certain medications.

According to search result [4], a case report published in 2014 described the use of sirolimus, an mTORC-1 inhibitor, for treating a patient with PTEN mutations. The treatment led to an improvement in the patient's clinical status and a transient reduction of the thymus.

Additionally, another study mentioned in search result [5] reported two successful attempts of oral treatment with sirolimus for patients with PTEN mutations.

However, it is essential to note that these reports are isolated cases, and there is no clear consensus on the use of drug treatment for LFH. Treatment is generally based on symptoms, and some patients may not experience any neurologic or functional complications [6].

It's also worth

Differential Diagnosis of Obsolete Lipomatous Hamartoma

Lipomatous hamartoma, also known as fibrolipomatous hamartoma or lipofibromatous hamartoma, is a rare benign intraneural tumor. When considering the differential diagnosis for this condition, several other peripheral nerve tumors and lesions should be taken into account.

• Intraneural Lipomas: These are benign tumors composed of mature adipose tissue that can mimic the appearance of lipomatous hamartoma on imaging studies.
• Neurilemmomas: Also known as schwannomas, these are benign nerve sheath tumors that can cause enlargement of the affected nerve.
• Ganglia: Intraneural ganglia are benign lesions composed of mature adipose tissue and can be confused with lipomatous hamartoma on histological examination.

In addition to these peripheral nerve tumors, other conditions should also be considered in the differential diagnosis for lipomatous hamartoma:

• Lipomas: These are benign fatty tumors that can occur anywhere in the body, including within nerves.
• Neurofibromatosis: This is a genetic disorder characterized by the growth of multiple non-cancerous tumors on nerve tissue.
• Lymphangioma: A rare congenital malformation of the lymphatic vessels that can cause swelling and enlargement of affected areas.

Key Points to Consider

• Imaging studies, such as MRI or CT scans, may be used to narrow down the differential diagnosis for lipomatous hamartoma by identifying fatty tissue within the tumor.
• Histological examination