Unusual Cutaneous Metastasis of Pancreatic Adenocarcinoma.

Case Report

Our patient was a 65-year-old woman with a past medical history significant for resectable pancreatic adenocarcinoma with no vascular involvement, stage IIA T3N0M0. She underwent potentially curative Whipple resection with negative margins and no lymph node involvement, followed by chemotherapy of 10 cycles of gemcitabine and 6 weeks of fluorouracil, with concurrent radiation therapy to the pancreatic bed.

One year after the resection, the patient presented to the dermatology clinic with a concerning lesion on her left forehead. The lesion had been present for 2 months, and it was steadily enlarging with purulent discharge. She had no evidence of metastatic or recurrent pancreatic disease based on her most recent imaging study, which occurred 2 months before symptom onset. Upon physical examination, there was a pearly papule with central ulceration and debris on the left forehead (Figure 1). Microscopic examination of a shave biopsy of the lesion showed a centrally ulcerated epidermis over a dermis containing variably sized neoplastic, infiltrative glands. A battery of immunohistochemical stains were performed to classify this neoplasm, including pankeratin, cytokeratin 7, cytokeratin 20, mammaglobin, and GATA3. The atypical glands stained positively for pankeratin and cytokeratin 7 (Figure 2), whereas GATA3 showed minimal focal staining. Cytokeratin 20 and mammaglobin stains were negative. The morphology of the neoplasm was compared to the patient’s previously resected pancreatic tumor from 1 year prior, and it was found to be morphologically identical. The morphology and immunohistochemical staining pattern were consistent with a metastatic pancreatic ductal adenocarcinoma.

Figure 1

Pancreatic metastasis on the patient’s forehead.

Figure 2

Skin shave pathology with (A) hematoxylin and eosin, (B) positive CK-7, and (C) pankeratin immunohistochemical stains highlighting the malignant glands (20x).

Cutaneous metastases from pancreatic cancer are rare.1 The most common site reported is the umbilicus, which is known as the “Sister Mary Joseph's nodule.”2 Nonumbilical cutaneous metastases are far less common, with only a few cases reported in the literature.3 These metastases often have a nonspecific clinical appearance and can be confused for more common cutaneous lesions.4 This case is unique because there were no signs of metastatic disease elsewhere, with the only sign of recurrence being the forehead metastasis. Clinicians should be aware of a such scenario, while keeping in mind that immunohistochemical staining can be useful to help identify the origin of the underlying tumor, providing guidance for further management.

Disclosures

Author contributions: K. Aloreidi and J. Berg wrote the manuscript and approved the final version. B. Patel and M. Atiq revised the manuscript for intellectual content. M. Atiq is the article guarantor.

Financial disclosure: None to report.

Informed consent was obtained for this case report.