Vulvar cancer is an uncommon gynecological malignancy that starts on the outer surface of the female genitalia, known as the vulva. Because many vulvar symptoms are caused by non-cancerous conditions, a definitive diagnosis relies on a sequential approach to confirm the presence of malignant cells. Understanding these diagnostic procedures is essential for effective management and treatment.
Initial Assessment and Screening
The diagnostic process begins with a detailed review of the patient’s medical history and a thorough physical examination. The doctor asks about symptoms, such as persistent itching, pain, or a non-healing lump or ulcer on the vulva. This discussion also covers risk factors, including a history of human papillomavirus (HPV) infection or chronic skin conditions like lichen sclerosus.
During the physical exam, the physician inspects the vulvar area for abnormal skin changes, discolorations, or masses. The doctor also palpates the groin to check for enlarged lymph nodes, which could indicate spread.
To gain a magnified view, a procedure called vulvoscopy may be performed using a colposcope. This specialized magnifying device allows the doctor to closely examine the vulvar skin and mucosa. Sometimes, a weak solution of acetic acid is applied to the suspicious area, causing abnormal cells to turn white and become more visible. This visual assessment helps pinpoint areas for the next definitive step: the tissue biopsy.
Confirming the Diagnosis Through Biopsy
A tissue biopsy is the most important diagnostic step, as it is the only way to definitively confirm the presence of cancer cells. The biopsy involves removing a small tissue sample for microscopic examination by a pathologist. This analysis confirms the cancer type, such as squamous cell carcinoma, and determines the depth of tumor invasion, which is a significant factor in staging.
Doctors use different biopsy techniques depending on the size and location of the lesion. A punch biopsy is the most common method, using a small cutting tool to remove a core sample of tissue under local anesthesia. This technique obtains a deep enough sample to assess the extent of invasion into underlying tissue layers.
An excisional biopsy removes the entire abnormality and can serve as both a diagnostic and treatment procedure for small lesions. For large or deeply invasive tumors, an incisional biopsy removes only a portion of the mass to confirm the diagnosis before a surgical plan is finalized. The pathologist then identifies the cellular architecture and characteristics of the malignant cells.
Assessing the Extent of Disease
Once the biopsy confirms cancer, additional tests determine the cancer’s stage. Staging describes the tumor size and whether it has spread from the vulva to other parts of the body, which is essential for creating the treatment plan. Assessment often focuses on the groin lymph nodes, as these are the first sites where vulvar cancer typically travels.
A sentinel lymph node biopsy (SLNB) is a specialized surgical procedure used to check for microscopic spread to these first-draining lymph nodes. A radioactive tracer, a blue dye, or both are injected near the tumor site and travel along the lymphatic pathways to the sentinel nodes. The surgeon uses a probe to locate and remove these one or two nodes.
If the sentinel nodes are free of cancer cells, it is unlikely the cancer has spread further, sparing the patient from extensive groin lymph node removal. Imaging techniques are also used to assess the primary tumor size and check for spread to distant organs.
Magnetic Resonance Imaging (MRI) of the pelvis is often preferred because it provides detailed images of soft tissues. This helps determine if the tumor has invaded nearby structures like the urethra, vagina, or anus.
Computed Tomography (CT) scans of the chest, abdomen, and pelvis look for evidence of spread to the lungs, liver, or other lymph node groups beyond the groin. In some cases, a Positron Emission Tomography (PET) scan is combined with a CT scan (PET-CT) to identify areas of increased metabolic activity characteristic of cancer cells. These imaging studies and the SLNB results collectively determine the final stage, guiding the therapeutic approach.