CASE #1
A 40-year-old man presented to the clinic for evaluation of a 1.1-cm blue papule on his right nares. The lesion had been present for 20 years, but he sought treatment now at the urging of his wife. There was no pain, pruritus, or burning. Dermatoscope examination demonstrated a uniform, steel-blue pattern of pigmentation. The otherwise healthy patient had no personal or family history of similar lesions.
CASE #2
The patient, a 45-year-old woman, was concerned about a 4- to 6-mm purple papule on her lower lip. She could not remember how long the lesion had been present. When pressure was applied during diascopy, the lesion blanched fully. No other lesions were found on examination. Although the papule was asymptomatic, the patient wanted to have it removed for cosmetic reasons.
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Click on "Next" for CASE #1 and "3" for CASE #2.
Diagnosis: Blue nevus
The man's nasal lesion was in all likelihood a blue nevus. Blue nevi are visible manifestations of dermal melanocytosis that occur in solitary blue or gray-blue papules. The most common sites of presentation are the head and neck, sacral region, and dorsal aspects of the hands and feet.
The estimated prevalence in adults is 3%-5% in Asians and 1%-2% in Caucasians. Blue nevi are rarely seen in African Americans. Women are affected twice as often as men. While most blue nevi first appear in older children and teenagers, lesions may develop at any age.
There are two variants of blue nevus: common and cellular. Common lesions are usually flat or slightly elevated with a smooth surface. Coloration ranges from gray-blue to bluish-black. The less common cellular nevi tend to be larger, ranging in size from 1 to 3 cm in diameter. Histologically, common blue nevi manifest with poorly melanized spindled melanocytes and deeply pigmented dendritic melanocytes without mitoses located in thickened collagen bundles, and scattered melanophages. Cellular blue nevi exhibit a more cellular appearance. Removal of blue nevi is necessary only if melanoma is suspected.
Blue nevi are benign and asymptomatic throughout life. Although malignant melanoma has arisen in association with cellular blue nevi, this development is rare. Such malignant change may be heralded by a sudden increase in size and occasionally ulceration. In addition, cases of eruptive blue nevi have been reported, often following skin trauma, such as sunburn. Blue nevi can also appear as part of a constellation of findings, including lentigines, atrial myxomas, mucocutaneous myxomas, and blue nevi (LAMB syndrome); nevi, atrial myxomas, myxoid tumors (neurofibromas), and ephelides (NAME syndrome); or the Carney complex. There is also a familial variant in which numerous blue nevi develop.
Conditions that must be ruled out include blue rubber bleb nevus, combined nevus, congenital nevus, dermatofibroma, hidrocystoma, Kaposi sarcoma, malignant melanoma, nevi of Ota and Ito, tattoo reactions, and venous lake.
After a thorough clinical and dermatologic examination, this patient's papule was thought to be a blue nevus and thus benign. He declined surgical treatment.
Dr. Scheinfeld is assistant clinical professor of dermatology at Columbia University in New York City, where he has a private practice.
Diagnosis: Venous lake
The woman was diagnosed with a venous lake, a dark blue-to-purple compressible papule caused by dilatation of venules. These lesions typically develop on sun-exposed skin, particularly the lips and the ears. A majority of patients (95%) are elderly men (average age 65). Most venous lakes are asymptomatic, although pain, tenderness, and excessive bleeding may occur if the area is traumatized.
The cause of venous lakes is as yet undefined. It is possible that chronic solar damage injures the skin's vasculature and ground substance, resulting in dilatation of superficial venous structures. Vascular thrombosis may also be a contributing factor because venous lakes commonly contain thrombi.
The most common differential diagnoses include blue nevus, cherry hemangioma, Kaposi sarcoma, malignant melanoma, and basal cell carcinoma. Diagnosis of venous lake is clinical. Diascopy performed by applying direct pressure against the lesion will cause the venous lake to blanch, sometimes incompletely as its contents are emptied; neoplastic mimics do not blanch, as they are not composed solely of blood vessels. Cherry angiomas and neoplasms, such as basal cell carcinoma or nodular melanoma, will not change color with diascopy. Dermatoscopy using an epiluminescence device will reveal a homogeneous reddish-blue to reddish-black color in the absence of pigment network structures. A shave biopsy can be performed for definitive diagnosis and removal. Other treatment modalities include cryotherapy, electrosurgery, laser therapy with a pulse dye laser (585-595 nm), carbon dioxide laser, or other laser and/or excision.
Two months after cauterization with a low-voltage epilating needle, only a trace of the lesion remained.
Dr. Scheinfeld is assistant clinical professor of dermatology at Columbia University in New York City, where he has a private practice.