From the Guidelines
A punch biopsy is not the preferred method for diagnosing a suspicious lesion on the thoracic back that is asymmetric, raised, and one color, as these features raise concern for possible melanoma, and instead, an excisional biopsy with 1-3 mm margins is recommended. For suspicious pigmented lesions, the recommended margins are 1-3 mm of normal-appearing skin around the visible border of the lesion, as stated in the guidelines by the Journal of the National Comprehensive Cancer Network 1. If melanoma is confirmed, wider excision will be needed based on the Breslow thickness. Punch biopsies can sample only a portion of the lesion, potentially missing the most concerning areas and compromising accurate diagnosis, staging, and treatment planning. Complete excision allows for comprehensive histopathological evaluation including assessment of symmetry, circumscription, and depth of invasion, which are critical for determining prognosis and treatment. The most recent and highest quality study, published in 2015 by the Annals of Oncology 1, also recommends a full-thickness excisional biopsy with a minimal side margin for diagnosis.
Some key points to consider when evaluating a suspicious lesion include:
- The ABCD rule, which characterizes suspicious lesions by Asymmetry, Border irregularities, Colour heterogeneity, and Dynamics 1
- The ugly duckling concept, which helps to identify melanomas by recognizing that naevi in the same individual tend to resemble one another, while melanomas often do not fit the individual's naevus pattern 1
- Dermoscopy by an experienced physician, which can enhance diagnostic accuracy 1
- The importance of processing the biopsy by an experienced pathology institute and following the American Joint Committee on Cancer (AJCC) classification 1
In terms of margins, the guidelines recommend:
- 1-3 mm margins for the initial excisional biopsy 1
- Wider margins for subsequent excisions, based on the Breslow thickness of the melanoma, with 0.5-1 cm margins for melanoma in situ, 1 cm margins for lesions <1 mm thick, and 1-2 cm margins for thicker lesions.
It is essential to prioritize complete excision and accurate diagnosis to ensure the best possible outcomes in terms of morbidity, mortality, and quality of life. Any suspicious pigmented lesion should be evaluated promptly, and if melanoma cannot be ruled out clinically, referral to dermatology or surgical oncology is warranted.
From the Research
Diagnosis and Biopsy of Thoracic Lesions
- For a suspicious lesion on the thoracic back that is asymmetric, raised, and one color, a punch biopsy may be considered as an initial diagnostic step 2.
- However, the provided studies do not directly address the appropriateness of punch biopsy for this specific type of lesion.
- A study on the diagnosis of intrathoracic lesions suggests that sequential fine-needle aspiration (FNA) and core needle biopsy (CNB) combined may be more accurate than either investigation alone 2.
Recommended Margins for Biopsy
- The studies provided do not specifically address the recommended margins for biopsy of a suspicious lesion on the thoracic back.
- A study on sentinel lymph node biopsy for melanoma discusses the importance of accurate identification and removal of the sentinel lymph node, but does not provide information on margins for biopsy of a primary lesion 3.
- Another study on sentinel lymph node biopsy highlights the importance of standardization and accuracy of sentinel lymph node identification, but does not address margins for biopsy of a primary lesion 4.
Sentinel Lymph Node Biopsy
- Sentinel lymph node biopsy is a valuable tool for staging melanoma, with reliable identification and detection of metastases 5, 6, 3, 4.
- However, the provided studies do not directly address the use of sentinel lymph node biopsy for a suspicious lesion on the thoracic back that is asymmetric, raised, and one color.