What is a Scalp Biopsy?
A scalp biopsy is a medical procedure in which a small section of the scalp skin, hair follicles, and sometimes underlying tissues are removed and examined under a microscope. This diagnostic tool is frequently employed to evaluate the underlying causes of hair loss, scalp lesions, and other dermatological conditions affecting the scalp.
Types of Scalp Biopsies
There are two primary types of scalp biopsies: Punch Biopsy: Involves using a circular blade to remove a small cylindrical section of the scalp, typically 4mm in diameter.
Excisional Biopsy: Involves removing a larger section of the scalp, usually if a bigger or deeper sample is required.
Procedure
The scalp biopsy procedure typically involves the following steps: Local Anesthesia is administered to numb the area.
A small section of the scalp is sterilized.
A punch tool or scalpel is used to remove the tissue sample.
The sample is then placed in a fixative solution (commonly formalin) for histological examination.
The biopsy site is closed with sutures and covered with a sterile dressing.
What Happens to the Sample?
The tissue sample is processed in a histology laboratory where it undergoes fixation, dehydration, embedding, sectioning, and staining, typically with
hematoxylin and eosin (H&E) stains. Specialized stains like PAS (Periodic Acid-Schiff) or immunohistochemical stains may also be used based on the suspected diagnosis.
Histological Examination
Under the microscope, the pathologist will evaluate various features such as: Hair follicle count and morphology
Presence of inflammatory cells
Signs of fibrosis or scarring
Changes in the epidermis and dermis
Any abnormal deposits or infectious agents
Interpretation and Diagnosis
The pathologist will compile the findings and generate a report that includes the histological features observed. This report is then reviewed by the dermatologist or clinician who will correlate the histopathological findings with clinical features to arrive at a definitive diagnosis.
Risks and Complications
Although generally safe, scalp biopsies can have minor risks and complications such as: Bleeding
Infection
Scarring
Temporary or permanent hair loss at the biopsy site
Conclusion
A scalp biopsy is a valuable diagnostic procedure in dermatology and histology, providing crucial insights into various scalp and hair disorders. The histological examination of biopsy samples helps identify the underlying causes, guiding effective treatment strategies.
