Purpose: Malignant adnexal neoplasms including eccrine carcinoma are extremely rare and difficult to characterise both clinically and pathologically. We present a patient presenting with four adenocarcinomas over a seven-year time course, each with unique immunohistochemical and molecular signatures. Methodology: Immunohistochemical and molecular sequencing results were analysed and compared between four specimens excised and reported as adenocarcinoma variants: a preauricular skin eccrine carcinoma (and its local recurrence), an ethmoid sinonasal adenocarcinoma, a right middle lobe adenocarcinoma, and an oesophageal adenocarcinoma. Results: A biopsy from the right preauricular skin lesion recurrence detected a TP53 variant (c.469G>T p.(V157F) at 12.6% VAF). This was present in the initial specimen on re-examination. The right lobectomy and oesophageal specimens detected the same TP53 variant, not present in the sinonasal tumour. The oesophageal adenocarcinoma demonstrated differing immunohistochemical characteristics (CK7, CK20, and CDX2). Following MDM discussions, these findings supported that the preauricular and oesophageal tumours were part of the same malignant process, and that the lung tumour represented metastatic disease from the preauricular eccrine carcinoma. Conclusion: Malignancies of cutaneous appendages present diagnostic challenges due to their lack of distinctive clinical and histological characteristics. Immunohistochemical findings give clues to their cellular origins. Molecular sequencing can facilitate a more definitive understanding. In this case, TP53 mutation sequencing distinguished a metastatic eccrine carcinoma from a pulmonary adenocarcinoma, with management and prognostic implications.