From the Guidelines
The correct term for the described skin lesion is a macule, as it is a flat, nonpalpable, circumscribed lesion. The description provided matches the characteristics of a macule, which represents a change in skin color without elevation or depression of the skin surface. Common examples of macules include freckles, flat moles, and certain rashes. In contrast to macules, papules are raised, palpable lesions less than 1 cm in diameter; nodules are larger, palpable lesions that extend deeper into the dermis; and wheals are edematous, irregular elevations of the skin that are often pruritic and transient, as seen in urticaria or hives. The key distinguishing feature of a macule is that it is flat and cannot be felt when running a finger over the skin surface. Although the provided evidence does not directly describe a macule, the characteristics of the lesion in question align with the definition of a macule, and this diagnosis is supported by general medical knowledge 1, 2. Some skin lesions, such as actinic keratosis, can have distinct presentations, including variants that range in appearance from atrophic to profoundly hypertrophic, but the description of a brown, flat, nonpalpable skin lesion is most consistent with a macule 1. Other types of skin lesions, such as lentigo maligna, may also be flat and pigmented, but the provided description does not suggest a specific diagnosis of lentigo maligna, and a macule is a more general term that encompasses a wide range of flat, nonpalpable lesions 2. Key characteristics of a macule include:
- Flat, nonpalpable lesion
- Less than 1 cm in diameter
- Change in skin color without elevation or depression of the skin surface
- Examples include freckles, flat moles, and certain rashes.
From the Research
Definition of a Brown, Flat, Nonpalpable Skin Lesion
- A brown, flat, nonpalpable skin lesion can be referred to as a melanotic macule or a solitary brown macule 3, 4.
- The term melanotic macule is used to describe a small, well-circumscribed melanocytic benign lesion that can occur on the lips and intraorally, ranging in color from brown to black 3.
- A solitary brown macule is a common skin lesion that may be benign or malignant, representing a disorder of melanocytes, nervus cells, or hemosiderin 4.
Characteristics of the Lesion
- The lesion is typically flat and nonpalpable, with a brown color 4.
- It can be difficult to clinically differentiate the lesion from a malignant tumor, and biopsy may be necessary for a definitive diagnosis 3, 4.
- Histologically, the lesion may show elevated levels of melanin production by basal melanocytes, which appear normal in terms of number, morphology, and distribution 3.
Related Conditions
- Nevus spilus is a pigmented skin lesion composed of a pigmented macule on which darker lesions appear at a later stage, and there have been reports of malignant melanoma occurring within these lesions 5, 6.
- Mucosal melanotic macule, reactive type, is a condition that simulates melanoma, but is characterized by the absence of pigment-laden dendritic cells in the basal layer of the epidermis 7.