obsolete Pilosebaceous hamartoma

Pilosebaceous Hamartoma: An Obsolete Term

A pilosebaceous hamartoma, also known as a basaloid follicular hamartoma or hair nevus, is an outdated term that was once used to describe a specific type of benign skin lesion. This condition is characterized by the abnormal growth of hair follicles and sebaceous glands in a localized area.

Key Features

• A pilosebaceous hamartoma typically presents as a small, flesh-colored papule or nodule on the head, neck, or upper chest.
• The lesion may be asymptomatic and slow-growing, with few cases reported.
• It is often associated with other skin lesions, such as fibrous papules, trichodiscomas, and fibrofolliculomas.

Current Understanding

The term "pilosebaceous hamartoma

Pilosebaceous Hamartoma: Signs and Symptoms

Pilosebaceous hamartomas are rare, benign growths that can occur on various parts of the body. While they may not be as commonly discussed as other skin conditions, understanding their signs and symptoms is essential for early detection and treatment.

• Skin manifestations: Pilosebaceous hamartomas can appear anywhere on the skin but are often found on the face, lips, and neck [7]. They may present as multiple papules and nodules, which can be hyperpigmented or dark brown in color [8].
• Pressure symptoms: As these growths develop, they can exert pressure on surrounding tissues or organs, leading to various symptoms. For instance, if a pilosebaceous hamartoma grows in the breast area, it may change the appearance of the breast [11]. In more severe cases, such growths can be life-threatening.
• Neurological symptoms: Pilosebaceous hamartomas can also cause neurological symptoms due to compression or infiltration of neural structures. These symptoms may include numbness and weakness in affected areas, limb atrophy, and progressive neuropathy [4].
• Other symptoms: Depending on the location and size of the growth, pilosebaceous hamartomas can cause a range of other symptoms, such as pruritus (itching), discomfort, or excessive sweating [6]. In rare cases, they may also lead to complications like pneumonia and bronchiectasis if located in the lungs.

It's essential to note that not all pilosebaceous hamartomas will exhibit these signs and symptoms. Some individuals may remain asymptomatic for extended periods, while others may experience minor complaints [6].

References:

[4] Common symptoms include progressive neuropathy (numbness and weakness) and limb atrophy. The most common location is the brachial plexus (25%), followed by other areas.

[6] These tumors show slow growth and can be asymptomatic for decades, and minor complaints have generally been recorded, such as pruritus, discomfort, a tense feeling, or excessive sweating.

[7] Trichoepithelioma is an uncommon, benign hamartomatous tumor of the pilosebaceous follicle. Presenting as multiple papules and nodules on face and neck, they may be hypertrichotic or painful.

[8] Hyperpigmented papules on anterolateral thigh, buttocks, and lower back have been reported in some cases.

[11] A common symptom from hamartoma growth is pressure, specifically when it begins pushing into other tissues or organs. If it grows, a hamartoma can change the appearance of the breast. In more severe cases, hamartoma growths can be life-threatening.

Diagnostic Tests for Pilosebaceous Hamartoma

Pilosebaceous hamartomas are benign growths that can be diagnosed using various imaging and diagnostic tests. While some of these tests may have been considered obsolete, they are still relevant in certain contexts.

• X-ray: X-rays were once used to diagnose pilosebaceous hamartomas, particularly those located in the skin (1). However, this method is no longer the preferred choice due to its limited ability to provide detailed images of soft tissues.
• Ultrasound: Ultrasounds are still used today to view internal organs and assess blood flow through various vessels. They can also be used to diagnose pilosebaceous hamartomas by visualizing the growth's characteristics (8).
• Computerized Tomography (CT) scans: CT scans show detailed images of any part of the body, including bones, muscles, fat, and organs. While not specifically mentioned in the context as a diagnostic test for pilosebaceous hamartoma, it can still be used to rule out other conditions or assess the growth's impact on surrounding tissues.
• Dermoscopy: Dermoscopy is an imaging technique that allows for the visualization of specific vascular structures not visible to the naked eye. It has been used to improve clinical diagnosis of nonpigmented skin tumors, including pilosebaceous hamartomas (7).

Other Diagnostic Procedures

In addition to these tests, other diagnostic procedures may be considered for pilosebaceous hamartoma, such as:

• Histopathological examination: A biopsy and histopathological examination can provide a definitive diagnosis by examining the growth's cellular structure.
• Clinical evaluation: A thorough clinical evaluation, including a physical examination and medical history, is essential to rule out other conditions that may mimic pilosebaceous hamartoma.

It is essential to note that the diagnostic approach for pilosebaceous hamartoma may vary depending on individual circumstances and the expertise of healthcare professionals involved.

Based on the provided context, it appears that Nevus comedonicus, a rare congenital pilosebaceous hamartoma, can be treated with various medications.

• Botulinum toxin: A study in 2009 successfully treated Nevus comedonicus with botulinum toxin, and the therapeutic response was maintained for several months [1].
• Isotretinoin: Although one case report showed a slight decrease in lesion size after treatment with isotretinoin (30 mg/d) for 3 months, the size returned to its original state after cessation of drug [2]. Another study mentioned that two giant variants were treated with Isotretinoin or Acitretin, but the outcome was not specified [8].
• Keratolytic agents: Salicylic acid and 0.1% retinoic acid have been reported as treatments for Nevus comedonicus, although specific outcomes are not provided in the context [5].

It's essential to note that these treatment options may vary depending on individual cases and their severity.

References: [1] D Barco (2009) - Successfully treated with botulinum toxin [2] S Haw (2009) - Isotretinoin treatment for 3 months, but size returned after cessation [5] E Aktaş Karabay (2020) - Keratolytic agents such as salicylic acid and 0.1% retinoic acid [8] R Tasar (2023) - Two giant variants treated with Isotretinoin or Acitretin