The biopsy specimen showed increased melanin within the basal layer of the epithelium, without an increase in melanocytes.
Our patient had hyperpigmentation of his oral and genital mucosa, palms, and soles. His hyperpigmentation was likely a manifestation of Laugier-Hunziker syndrome. A variety of conditions must be excluded before this diagnosis can be made.
One common cause of hyperpigmentation of oral mucosa is melanoplakia. Melanoplakia, commonly described as physiologic, is common in dark-skinned individuals.1 Although our patient had a dark complexion, the distribution of the hyperpigmentation, particularly the maculae on the buccal and labial surfaces, made this diagnosis less likely. Peutz-Jeghers syndrome is an autosomal dominant condition that begins in early childhood and is characterized by hyperpigmented maculae on the skin and oral mucosa and by harmartomatous polyps of the gastrointestinal tract.2 The diagnosis of Peutz-Jeghers syndrome was considered less likely in our patient because there was no family history of pigmentary abnormalities or evidence of harmartomatous polyps. Addison disease, or primary adrenal insufficiency, is characterized by diffuse hyperpigmentation of the skin, with a predilection for genitalia, areolae, traumatized areas, and creases. The oral mucosa can demonstrate pigmentary changes.3 Our patient's lack of related symptoms and signs, such as weight loss, fatigue, hypotension, and electrolyte abnormalities, ruled out this diagnosis. Albright syndrome is the constellation of polyostotic fibrous dysplasia, precocious puberty, and pigmentary abnormalities. Frequently, there is abnormal pigmentation of the lips.4 Our case did not fulfill the criteria for this diagnosis. Finally, the patient's medications were unlikely to have caused these pigmentary changes.
Perioral and Acral Lentigines in an African American Man. Arch Dermatol. 2000;136(3):417-422. doi: