SAN FRANCISCO Vulvar granular cell tumors are biologically indolent lesions that may progress clinically over a decade or longer and most often occur in black patients, according to a recent review.
Of 16 granular cell tumors of the vulva that were surgically removed, 7 had positive margins, and only 1 progressed to a size requiring reexcision after 14 years, Dr. John A. Papalas and his associates reported at the annual meeting of the American Society of Dermatopathology. None of the tumors at the time of initial excision met histological criteria for malignancy.
The 16 lesions occurred on 12 patients (including 10 black patients) who were seen at Duke University, Durham, N.C. The patients' average age was 46 years.
The question of whether to reexcise a vulvar granular cell tumor with positive margins should be considered carefully because of the greater morbidity, compared with excisions in other areas of the body, noted Dr. Papalas of Duke University.
In a previous report on 20 patients with vulvar granular cell tumors, investigators suggested obtaining wide negative surgical margins (up to 2 cm), but the study provided follow-up data on only 1 patient and did not report the surgical margin resection status, he pointed out (Am. J. Obstet. Gynecol. 1995;173:1710-3).
Given the findings of the current study, which show that these tumors rarely recurred regardless of surgical margin status, "a 2-cm margin of a benign tumor on the vulva seems a bit excessive," one physician in the audience commented.
Patients with multiple vulvar granular cell tumors rarely have been reported in the literature. Three patients in the current series had multiple vulvar granular cell tumors and additional granular cell tumors in another body area. Another patient had a single vulvar tumor and an isolated lesion in another body area. Eight patients had a single granular cell tumor on the vulva alone. Extravulvar sites included the groin, perirectal area, buttock, esophagus, neck, buccal mucosa, and scalp.
Of the three patients with multiple vulvar granular cell tumors, only one presented with multiple vulvar lesionsa 50-year-old woman (just 2 years older than the average age), Dr. Papalas noted. Two other patients with an average age of 30 years presented with a single vulvar granular cell tumor and later progressed to multiple vulvar lesions over a 14-year period after the initial excision.
The surgical note or pathology report should precisely document the tumor location in order to accurately track recurrence or progression, he advised. Simply saying the tumor is on the "vulva" is not good enough, because the vulva is an anatomically complex region. The most common location of lesions in the current series was the labia majora, for 7 of 16 tumors.
Grossly, the tumors in this series either were well-circumscribed tan/white nodules or infiltrative masses, with an average tumor size of 2 cm.
A granular cell tumor is a Schwann cell-derived neoplasm that can occur throughout the body. Most involve the skin and soft tissue. Biopsies classically show tumor cells with abundant, pink granular cytoplasm and monomorphic, bland nuclei, though they can be mistaken for other lesions. "They're not always a slam-dunk diagnosis," Dr. Papalas said.
Granular cell tumors appear to be the most common peripheral nerve sheath-derived neoplasm in the vulva, he added.