Table 38.8 Prognosis for Patients with Vulvar Melanoma Stratified by Breslow Microstaging
DOD, died of disease. aAll but one of these seven deaths were reported in one study with an unusually low 5-year survival of 48% for 12 patients with superficial melanomas of Breslow thickness <0.76 mm. If these 12 cases were excluded, 5% of patients with superficial melanoma of the vulva died of disease. From references 160, 165, 174, 185, 186, 196–199.
Prognosis The behavior of melanomas can be unpredictable, but the prognosis is poor. The reported 5year overall survival rate for vulvar melanoma is in the range of 50% to 60% (158,159,171). A SEER database analysis showed disease-specific survival rates for patients with localized, regional, and distant disease of 76%, 39%, and 22%, respectively (171). Localized disease, negative lymph nodes, and younger age were significant independent prognostic factors for improved survival. Because vulvar melanoma has a propensity for late recurrences, 5-year survival may not reﬂect cure. Prognosis is best predicted by microstaging. Patients with lesions invading to 1 mm or less have a good prognosis, but as depth of invasion increases, the prognosis worsens (Table 38.8). Tumor volume is reported to correlate with prognosis; patients whose lesions have a volume less than 100 mm3 have an excellent prognosis (184). Additional prognostic factors are the patient’s age, AJCC stage, presence of multifocal or satellite lesions, tumor ulceration, central tumor location, histologic growth pattern, lymph–vascular space involvement, and aneuploidy (158,162–164,194–197).
Epidemiology Primary carcinoma of the Bartholin gland is a rare form of vulvar cancer, which accounts for about 2% to 7% of vulvar malignancies (198). Because of its rarity, individual experience with the tumor is limited, and recommendations for management must be based on the review of small published series. Only about 300 cases are reported (46,198,199). Bartholin gland carcinoma is five times more common in postmenopausal than in premenopausal women (200).
Histopathology The bilateral Bartholin glands are greater vestibular glands situated posterolaterally in the vulva. Their main duct is lined with stratified squamous epithelium, which changes to transitional epithelium as the terminal ducts are reached. Because tumors may arise from the gland or the duct, a variety of histologic types occur, including adenocarcinomas, squamous carcinomas, and, rarely, transitional cell, adenosquamous, and adenoid cystic carcinomas.
Classification of a vulvar tumor as a Bartholin gland carcinoma typically required that it fulfill Honan’s criteria, which are as follows: 1.
The tumor is in the correct anatomic position.
2.
The tumor is located deep in the labium majus.
3.
The overlying skin is intact.
4.
There is some recognizable normal gland present.
Strict adherence to these criteria results in underdiagnosis of some cases. Large tumors may ulcerate through the overlying skin and obliterate the residual normal gland. Although transition between normal and malignant tissue is the best criterion, some cases will be diagnosed on the basis of their histologic characteristics and anatomic location.
Table 38.9 Survival of Patients with Bartholin Gland Carcinoma