What is the initial workup for a suspicious, non-tender (not tender to the touch) mass in the inguinal (groin) region for potential malignancy (cancer)?

From the Guidelines

The initial workup for a nontender inguinal mass suspicious for malignancy should include a thorough physical examination, followed by imaging studies and biopsy, with a strong emphasis on assessing the groin for palpable or suspicious nodes, as recommended by the European Association of Urology-American Society of Clinical Oncology collaborative guideline on penile cancer: 2023 update 1. The physical examination should assess the size, consistency, mobility, and relationship to surrounding structures of the mass, as well as examination of the genitalia, abdomen, and other lymph node regions.

• A detailed physical examination of the penis and external genitalia is crucial, recording the morphology, size, and location of the penile lesion, including the extent and invasion of penile (adjacent) structures, as stated in the guideline 1.
• A physical examination of both groins should be performed, recording the number, laterality, and characteristics of any palpable/suspicious inguinal nodes, as recommended by the guideline 1. Imaging studies should begin with ultrasound, which can differentiate between solid and cystic masses and provide information about vascularity.
• If there are no palpable/suspicious nodes (cN0) at physical examination, inguinal US should be offered first, with fine-needle aspiration cytology of sonographically abnormal LNs, as recommended by the guideline 1.
• If there is a palpable/suspicious node on physical examination (cN+), obtain (image-guided) biopsy to confirm nodal metastasis before initiating treatment, as stated in the guideline 1. The definitive diagnostic step is a tissue biopsy, preferably an excisional biopsy if the mass is small enough, or an incisional or core needle biopsy for larger masses.
• Obtain a pretreatment biopsy of the primary lesion when malignancy is not clinically obvious, or when nonsurgical treatment of the primary lesion is planned, as recommended by the guideline 1. Laboratory tests including complete blood count, comprehensive metabolic panel, and lactate dehydrogenase should be ordered as baseline studies. This systematic approach allows for accurate diagnosis and staging, which are essential for determining appropriate treatment strategies for potential malignancies in the inguinal region.

From the Research

Initial Workup for Suspicious Inguinal Mass

The initial workup for a suspicious inguinal mass involves several diagnostic steps to determine the presence of malignancy.

• The first step is to perform an ultrasound (US) of the inguinal region to assess the mass and guide further diagnostic procedures 2.
• If the US is suspicious, a fine-needle aspiration (FNA) or core biopsy may be performed to obtain tissue for pathological examination 3, 4.
• FNA has a lower diagnostic accuracy compared to core biopsy, with a sensitivity of 79.17% and a specificity of 72.7% for determining malignancy 3.
• Core biopsy, on the other hand, has a higher diagnostic accuracy, with a sensitivity of 79.2% and a specificity of 81.8% for determining malignancy 3.
• In some cases, a combination of FNA and core biopsy may be used to increase the diagnostic yield 5, 6.
• The choice of diagnostic procedure depends on the clinical presentation, the size and location of the mass, and the availability of imaging guidance 2, 4.

Diagnostic Performance of Biopsy Procedures

The diagnostic performance of biopsy procedures for suspicious inguinal masses can vary depending on the type of procedure and the clinical context.

• A study comparing FNA, core biopsy, and surgical biopsy found that core biopsy had a higher diagnostic accuracy than FNA, with a sensitivity of 79.2% and a specificity of 81.8% for determining malignancy 3.
• Another study found that US-guided core biopsy had a higher diagnostic yield than FNA, with a sensitivity of 100% and a specificity of 100% for determining malignancy 4.
• A retrospective review of 861 US-guided biopsies of head and neck lymph nodes and masses found that the diagnostic performance of FNA with optional core biopsy was excellent, with a sensitivity of 98.3% and a specificity of 99.5% for determining malignancy 5.

Clinical Implications

The initial workup for a suspicious inguinal mass has important clinical implications for patient management and treatment.

• Accurate diagnosis of malignancy is crucial for guiding treatment decisions, such as surgery, chemotherapy, or radiation therapy 2, 6.
• The choice of diagnostic procedure should be based on the clinical presentation, the size and location of the mass, and the availability of imaging guidance 2, 4.
• A multidisciplinary approach, involving radiologists, pathologists, and clinicians, is essential for ensuring accurate diagnosis and effective treatment of suspicious inguinal masses 6.