Two late-diagnosed cervical melanomas underscore rarity and diagnostic challenges

Doctors in Taiwan reported two cases of primary malignant melanoma of the cervix — an exceptionally rare and aggressive cancer — in which patients initially dismissed a single symptom and were diagnosed after the disease had advanced.

In a case series published in the American Journal of Case Reports, clinicians described a 69-year-old and a 75-year-old woman who each experienced roughly one month of irregular vaginal bleeding before seeking care. Imaging and biopsies in both patients revealed large, pigmented cervical masses consistent with malignant melanoma. One patient was diagnosed with advanced disease that had already spread beyond the cervix; despite chemoradiotherapy and immunotherapy, her condition progressed and she died months after diagnosis. The other patient underwent surgery and periods of disease control but ultimately died years after her diagnosis.

Primary malignant melanoma of the cervix (PMMC) is extremely uncommon. Melanomas of the female genital tract account for about 3 percent of melanomas in women, with the vast majority arising in the vulva or vagina. Cervical melanomas represent only about 3 to 9 percent of those genital-site melanomas — a fraction that translates to an estimated 0.0009 percent to 0.0027 percent of all melanomas in women, according to figures cited by the authors. A 2020 literature review noted fewer than 100 reported cases of PMMC.

Unlike the more familiar cutaneous melanomas linked to ultraviolet exposure, gynecologic melanomas originate in melanocytes — pigment-producing cells that are also present in mucosal linings. Because they can develop in non–sun-exposed tissues, these tumors do not have the same risk profile as skin melanoma. They are frequently aggressive, often present with few or nonspecific symptoms, and carry a poor prognosis.

Signs that have been reported for genital melanomas include pain, irregular bleeding or discharge, but some patients may have no symptoms until the tumor is large. The two patients in the Taiwanese report both presented with bleeding but no other prominent complaints; one also reported dizziness and fatigue. Magnetic resonance imaging in the cases showed large cervical masses, and biopsies identified the lesions as malignant melanoma.

Treatment options for PMMC are not standardized. The Taiwanese physicians said selecting an optimal course of care was “particularly challenging due to the absence of standardized guidelines.” In the two cases they treated, they observed that surgical intervention correlated with improved survival outcomes, though one patient experienced recurrence after initial surgery. Other treatments used in gynecologic melanomas have included combinations of surgery, radiation, chemotherapy and, in some cases, immunotherapy, but responses vary and evidence is limited to case reports and small series.

Obstetrician-gynecologist Catherine Tucker, who was not involved with the study, told reporters that five-year survival rates for gynecologic melanomas have been reported in the range of about 5 percent to 25 percent. The authors of the case series echoed that the overall prognosis for cervical melanoma is poor and emphasized the need for more research to develop standardized treatment protocols.

The clinicians recommended raising awareness among frontline clinicians and improving early diagnostic strategies to increase the chance of successful treatment. They noted that cervical melanoma is most often observed in postmenopausal women, typically between ages 60 and 70, but cases have been reported in younger patients as well.

Given the rarity of PMMC and the limited data on outcomes, the authors urged that new cases be reported and compiled to help inform future practice guidelines. They said that earlier recognition of unusual vaginal bleeding or other atypical symptoms in older women could prompt earlier investigation and potentially improve management and quality of life for patients facing this rare malignancy.