On the safe side: New classification 'Spitzoid tumor' signals cautious treatment

Key Points

International report - Clinically recognizing and diagnosing a Spitz nevus is a challenge. Many experts are not so quick to commit to a definitive diagnosis at first inspection, as the differential diagnosis of a melanoma may loom in the wings.

According to one specialist, histopathologists have created a new entity known as the "Spitz tumor," making dermatologists alter the way they treat this histopathologically unclear skin lesion.

Difficult diagnosis

"In the past, a clinically atypical lesion resembling melanoma would be removed, and only then would we be sure if it is a melanoma or Spitz nevus," says Giuseppe Argenziano, M.D., department of dermatology, Second University of Naples, Italy.

According to Dr. Argenziano, a Spitz nevus can very often clinically mimic a melanoma. However, with the help of dermoscopy, dermatologists can be much more accurate and secure in their diagnoses of lesions, including Spitzoid lesions, which include Spitz nevi and spitzoid melanomas.

"In general, the definition of a Spitzoid lesion is some entity between a Spitz nevus and a Spitzoid melanoma.

"A Spitzoid lesion is something that you can not define as a clear-cut Spitz nevus, but at the same time, you can not say that it is a clear-cut melanoma, histologically," Dr. Argenziano tells Dermatology Times.

Casting doubt

A clinician admits to his or her doubt in the diagnosis by labeling a lesion as a Spitzoid lesion, as clinically, these lesions could very well be either a Spitz nevus or spitzoid melanoma.

It is not uncommon at all for histopathologists to have difficulty differentiating these melanocytic skin tumors, because morphologically, these lesions are very similar.

"Theoretically, we, as clinicians, have to recognize that a lesion could be spitzoid. As a rule, if the clinician is completely sure that the lesion is a Spitz nevus or, on the contrary, if you are sure that the lesion is a Spitzoid melanoma, you have to perform an excisional biopsy and completely remove the lesion," Dr. Argenziano says.

According to Dr. Argenziano, there is a price to be paid for removing some benign Spitz nevi, but by following this cautious therapeutic path, the dermatologist is potentially avoiding the catastrophe of the lesion actually being a melanoma.

Dr. Argenziano says that if the clinician follows this therapeutic path, he or she is "absolved" of potential harm to the patient.

However, where the problem for clinicians ends is where the problem for pathologists begins, as they now have to step up and make a definitive, histopathologically proven diagnosis.

Dr. Argenziano says histopathologists have developed a new term to help them escape this diagnostic limbo when analyzing these histopathologically troublesome lesions.

A new entity

Histopathologists have invented the name "spitzoid tumors" - a term for classifying this kind of gray-zone lesion, as it is not completely clear if such lesions are benign or malignant.

"With this new terminology, they are sending a clear message to the clinician that they are in a state of indecision concerning the malignant potential of the tumor, so the clinician must adapt and treat the lesion as if it were a melanoma," Dr. Argenziano says.

According to Dr. Argenziano, this means close clinical follow-up, as well as a wider excision of the operated area. In rare occasions, a sentinel biopsy can be performed to be absolutely on the safe side.

With this new entity, "spitzoid tumor," dermatologists and histopathologists take a step closer to a "better-safe-than-sorry" mind frame in diagnosing patients with questionable lesions. Now, these patients receive a "safer" treatment instead of one based on an educated guessing game.