Considering genetics, as well as clinical presentation, will aid in managing challenging cases of skin cancer. It is also incumbent upon clinicians to conduct a comprehensive review of the medical literature to assess the risks associated with metastases of some lesions, such as proliferating trichelemal tumors, according to an expert who treats mainly skin cancer cases.
Clara Curiel, M.D., assistant professor of dermatology and medicine at the Arizona Cancer Center, University of Arizona, has seen a case of a woman with a history of basal cell carcinoma on the right cheek, who presented with small flesh-colored papules alongside her recently excised nonmelanoma skin cancer.
The lesion was biopsied and found to be a microcystic adnexal carcinoma (MAC). The tumor was successfully excised by Mohs surgery.
Upon further evaluation, a similar papule measuring 2 mm in size was identified on the right upper cutaneous lip. Histological evaluation also confirmed the presence of MAC.
"I had to review the literature about this condition, and there was not much information about alternative therapeutic interventions in addition to surgical excision in the literature," says Dr. Curiel, who treats mainly skin cancer cases.
"It's a challenge to manage extensive subclinical tumors. Ideally, one would like to understand the extension of the tumor up front, particularly if it measures several centimeters in diameter, and when the lesion is located in cosmetic sensitive areas like the face. It is important for the patients to know up front the possible extension of the tumor," she says.
According to the literature, radiation doesn't seem to be an option, because some of the tumors have the risk of recurring with more aggressive behavior, Dr. Curiel tells Dermatology Times.
Dr. Curiel has consulted with clinicians at other institutions regarding the management of the multiple MACs, and the consensus on therapeutic management was that the patient should undergo Mohs surgery with plastics reconstruction.
In another case, Dr. Curiel saw a patient who presented with a lump that she had had on her right hip for eight years. The lump continued to grow in size and became irritated, so the lesion was surgically excised.
"It was an entity known as a proliferating trichelemal tumor (PTT)," Dr. Curiel says.
"The unusual aspect is that there was a large focus of well-differentiated squamous cell carcinoma (SCC) arising in the context of this tumor.
"In addition, the location was not typical, since most PTTs usually present in the head and neck area," she says.
Malignant PTTs are rare, with only about 180 cases having been described in the literature.
"The key point is that you need to review the entire literature, and understand the risk associated with potential metastases in this type of presentation," Dr. Curiel says.
"There is a diagnostic as well as management challenge," she says.
With SCCs arising in the context of a PTT, Dr. Curiel says there are several considerations.
According to the histological features of the malignant component, clinicians need to decide if a sentinel lymph node biopsy is warranted to determine if the tumor has spread to regional lymph nodes; if there is an option of adjuvant radiation following surgical excision; and if proper metastatic surveillance should be set in place.
A discussion with the patient is necessary, since the patient needs to make an informed choice about the management of the tumor, according to Dr. Curiel.
"It's not just a question of taking out the tumor," she says. "You want to take a step back and think about what else can we do to see the pattern of spread and what would be the appropriate follow-up for the patient."
Li Fraumeni syndrome
Another unusual case was a patient who presented with multiple primary cutaneous melanomas, and had Li Fraumeni syndrome.
"When we start diagnosing more than one invasive melanoma in a patient, we need to start thinking about the genetics of the patient," Dr. Curiel says.
The patient first presented with an osteosarcoma of the mandible several years prior to her visit to the pigmented lesion clinic. The clinician had biospied three of her pigmented lesions at presentation, and found that they all were intermediate-thickness melanomas.
"They did not look like textbook melanomas. They looked like slightly atypical, pigmented lesions. Given the patient's history of an osteosarcoma, I thought about the patient's genetic background and possible association of p53," Dr. Curiel says.
"The case highlights that you can't base the decision to biopsy solely on clinical appearance," she says. "You need to think about the context of the patient. In this case, the patient had a history of osteosarcoma and multiple pigmented lesions with no family history of melanoma."