Hidden Basal Cell Carcinoma in the Intergluteal Crease

Practice Gap

Basal cell carcinoma (BCC) is the most common cancer, and its incidence is on the rise.¹ The risk of this skin cancer is increased when there is a history of squamous cell carcinoma (SCC) or BCC.² Basal cell carcinoma often is found in sun-exposed areas, most commonly due to a history of intense sunburn.³ Other risk factors include male gender and increased age.⁴

Eighty percent to 85% of BCCs present on the head and neck⁵; however, BCC also can occur in unusual locations. When BCC presents in areas such as the perianal region, it is found to be larger than when found in more common areas,⁶ likely because neoplasms in this sensitive area often are overlooked. Literature on BCC of the intergluteal crease is limited.⁷ Being educated on the existence of BCC in this sensitive area can aid proper diagnosis.

The Technique and Case

An 83-year-old woman presented to the dermatology clinic for a suspicious lesion in the intergluteal crease that was tender to palpation with drainage. She first noticed this lesion and reported it to her primary care physician at a visit 6 months prior. The primary care physician did not pursue investigation of the lesion. One month later, the patient was seen by a gastroenterologist for the lesion and was referred to dermatology. The patient’s medical history included SCC and BCC on the face, both treated successfully with Mohs micrographic surgery.

Physical examination revealed a 2.6×1.1-cm, erythematous, nodular plaque in the coccygeal area of the intergluteal crease (Figure 1). A shave biopsy disclosed BCC, nodular type, ulcerated. Microscopically, there were nodular aggregates of basaloid cells with hyperchromatic nuclei and peripheral palisading, separated from mucinous stromal surroundings by artefactual clefts.

Figure 1. Basal cell carcinoma in the coccygeal region.

The initial differential diagnosis for this patient’s lesion included an ulcer or SCC. Basal cell carcinoma was not suspected due to the location and appearance of the lesion. The patient was successfully treated with Mohs micrographic surgery.

Practical Implications

Without thorough examination, this cancerous lesion would not have been seen (Figure 2). Therefore, it is important to practice thorough physical examination skills to avoid missing these cancers, particularly when examining a patient with a history of SCC or BCC. Furthermore, biopsy is recommended for suspicious lesions to rule out BCC.

Figure 2. Hidden coccygeal lesion.

Be careful not to get caught up in epidemiological or demographic considerations when making a diagnosis of this kind or when assessing the severity of a lesion. This patient, for instance, was female, which makes her less likely to present with BCC.⁸ Moreover, the cancer presented in a highly unlikely location for BCC, where there had not been significant sunburn.⁹ Patients and physicians should be educated about the incidence of BCC in unexpected areas; without a second and close look, this BCC could have been missed.

Final Thoughts

The literature continuously demonstrates the rarity of BCC in the intergluteal crease.¹⁰ However, when perianal BCC is properly identified and treated with local excision, prognosis is good.¹¹ Basal cell carcinoma has been seen to arise in other sensitive locations; vulvar, nipple, and scrotal BCC neoplasms are among the uncommon locations where BCC has appeared.¹² These areas are frequently—and easily—ignored. A total-body skin examination should be performed to ensure that these insidious-onset carcinomas are not overlooked to protect patients from the adverse consequences of untreated cancer.¹³