# A Rare Case of Eccrine Carcinoma Demonstrating Intracranial Invasion in a Patient With Advanced Hepatocellular Carcinoma

## TL;DR

A rare case of eccrine carcinoma invading the skull in a patient with advanced liver cancer is reported, highlighting the need for better detection of secondary tumors.

## Contribution

This is the first reported case of intracranial invasion by eccrine carcinoma in a patient with untreated hepatocellular carcinoma.

## Key findings

- CT imaging showed a left frontal skull mass with soft tissue density in the patient.
- Immunostaining confirmed the tumor as eccrine carcinoma with specific marker positivity.
- The patient's lack of treatment due to socioeconomic factors highlights challenges in managing rare tumors.

## Abstract

Eccrine carcinoma (EC) is a rare intraepidermal carcinoma of the eccrine sweat glands. Even more rare are instances of EC exhibiting intracranial invasion. Here, we describe the case of a metachronous EC mass demonstrating intracranial invasion in a patient with advanced-stage hepatocellular carcinoma (HCC), reporting CT head findings of a left frontal skull expansile destructive mass with soft tissue density and immunostain findings of the following: CEA: positive, granular, EMA: positive, AE1/AE3: positive, CK7: strongly positive, CK20: negative, GCDFP: negative, and HEPAR: negative. The only recommended treatment for EC is surgical excision with tumor-free margins, and no chemotherapy protocols currently exist. Due to socioeconomic factors, our patient was unable to receive adequate treatment for her HCC, nor surgical excision for her EC. However, the unique presentation of a rare intracranial EC tumor causing no neurological deficits in a patient with untreated HCC merits the need for a more thorough identification of secondary tumors via biopsy in patients with HCC to identify possible associations between these two tumors in future patients.