Characterization of a single liver cystic mass: a metastasis of squamous cell carcinoma of the nasopharynx

Abstract

Introduction:

Liver cystic metastases (LCM) from squamous cell carcinoma (SCC) are exceedingly rare.

Case presentation:

This case report presents a 42-year-old man with a solitary liver cystic lesion, initially mimicking benign or infectious etiologies. Despite extensive radiological workup, the diagnosis remained elusive. Ultimately, a percutaneous biopsy revealed metastatic, non-keratinizing SCC, with the primary tumor subsequently identified in the pterygopalatine fossa.

Conclusion:

This case highlights the diagnostic challenges posed by solitary LCM, emphasizing the importance of considering rare malignancies in the differential diagnosis. Although imaging modalities such as magnetic resonance imaging are valuable, definitive diagnosis often requires histopathological confirmation. This case underscores the need for a high index of suspicion for SCC as a potential primary tumor in patients with unexplained liver cystic lesions.

Introduction

Squamous cell carcinoma (SCC) rarely metastasizes to the liver, and liver cystic metastases (LCM) are associated with a very poor prognosis[1]. When no known malignancy is present, the radiological features of LCM can mimic those of other benign or malignant cystic lesions, particularly those of infectious origin. The solitary nature of the hepatic lesion further complicates the diagnosis.

This report describes a case of a patient with a previously undiagnosed SCC arising in the pterygopalatine fossa. The initial presentation was a solitary cystic metastasis in the liver.

This case report has been reported in line with the SCARE checklist[2].

HIGHLIGHTS

• Characterizing solitary liver cystic metastasis (LCM) is challenging.

• Differential diagnosis includes hepatic complex cystic masses.

• Magnetic resonance imaging aids, but percutaneous fine-needle aspiration biopsy is essential for definitive diagnosis.

• Radiologists need a high level of suspicion for early LCM diagnosis.

• Squamous cell carcinoma can be a source of cystic liver metastases.

Case presentation

A 42-year-old man with a 6-year history of type B viral hepatitis presented with right upper quadrant (RUQ) abdominal pain and recent weight loss. Physical examination revealed hepatomegaly and mild tenderness in the upper right quadrant. The patient was afebrile and non-jaundiced. Laboratory workup showed no evidence of inflammation, and liver function test results were within normal limits.

Ultrasound identified a centrally located 6.1 × 7.0 cm LCM with lobulated margins, a hypoechoic structure with subtle heterogeneity, and posterior enhancement (Fig. 1A). Subsequent thoracoabdominal computed tomography (CT) (Fig. 1B–D) confirmed the presence of a single cystic mass in liver segment IV. The mass showed irregular borders and septa with moderate enhancement after contrast administration. These features helped exclude hemorrhagic biliary cyst and liver hydatid cyst (LHC, further supported by negative hydatid serology). There were no mural nodules, parietal or intracystic calcifications, vascular invasion, liver distortion, or portocaval anomalies.

Figure 1.

(A) Ultrasound view showing a centrohepatic multilocular and complex cystic lesion (7 cm) with poorly defined boundaries and a posterior enhancement. (B and C) Computed Tomography (CT) on axial (B) and coronal sections (C) showing a heterogeneous cystic lesion involving segments IV, V, and VIII of the liver with thick septations (Red arrow) that enhance after the contrast medium injection. There is no liver dysmorphia. (D) CT-scan axial view showing a bulky adenopathy (37 × 23 mm) of the hepatic hilum.

Differential diagnoses included cystic metastasis, cystic hepatocellular carcinoma (HCC) (given the patient’s history of hepatitis B), biliary cystadenoma, or cystadenocarcinoma. However, carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) levels were normal.

Magnetic resonance imaging (MRI) of the liver was performed to confirm the solitary nature and cystic characteristics of the mass. MRI revealed T1-hypointense and T2-hyperintense lesions, consistent with a fluid-filled structure. The mass was multilobulated with septa and showed moderate contrast enhancement during the portal phase. Minimal arterial-phase enhancement of the cyst wall and septa has been suggested to prevent HCC. The mass abutted the portal branches but showed no signs of invasion. There were no mural nodules, intracystic vegetation, bile duct dilatation, or capsular retraction (Fig. 2), making cholangiocarcinoma less likely.

Figure 2.

Hepatic MRI showing central multilocular hepatic cystic mass involving segments IV, V, and VIII with low T1 signal (A), high T2 signal (B), and restricted diffusion (b 600) (C). It presents thick septations that enhance moderately after Gadolinium injection without wash-in (D) or wash-out (E).

Given the remaining diagnostic uncertainty, a CT-guided percutaneous biopsy was performed. Pathological examination revealed poorly differentiated metastatic non-keratinizingSCC (Fig. 3). Cervical CT revealed a locally advanced right pterygopalatine fossa tumor. Biopsy of the nasopharyngeal mass confirmed an undifferentiated carcinoma, consistent with the histology of the LCM. The patient was subsequently referred for palliative chemotherapy.

Figure 3.

(A) Liver biopsy showing solid sheets of undifferentiated large tumor cells (HE ×200). (B) Diffuse and strong immunostaining of tumor cells for p40. (×200).

Discussion

Liver cystic lesions are identified in up to 5% of the general population[3]. These lesions can be benign, such as biliary cysts, LHCs, Caroli disease, and pyogenic abscesses. Less commonly, they may represent malignant tumors like biliary cystadenomas, cystadenocarcinomas, cystic hepatic cholangiocarcinomas, or cystic metastases^[3,4^].

Ovarian and pancreatic cystadenocarcinomas, as well as carcinoid tumors, are the most frequent primary cancers that metastasize to the liver in cystic form. SCC and sarcomas (leiomyosarcoma or others) are even rarer causes of cystic liver metastases, with only a handful of reported cases of SCC[4].

Diagnosing LCM is simplified when a primary malignancy is already known, there are multiple liver lesions with varying appearances, or the lesions demonstrate progressive growth[5]. However, characterizing a solitary LCM can be challenging due to the nonspecific nature of clinical, laboratory, and radiological findings.

The cystic nature of a liver metastasis can be attributed to necrosis. However, it can also represent true cystic differentiation, presenting with heterogeneous and poorly defined borders, irregular and incomplete septa, and occasional mural nodules on the inner surface[6].

A thick and irregular cystic wall that enhances significantly with contrast medium injection (CMI) suggests a malignant origin for a hepatic complex cystic mass (HCCM). Additionally, a hemorrhagic component may indicate an aggressive and rapidly progressive lesion.

Liver MRI plays a crucial role in diagnosing LCM because the contrast resolution allows for a detailed evaluation of both the cystic wall and its content. Here is a breakdown of the characteristic imaging features for the main causes of HCCM:

1. Liver cystadenocarcinoma: It appears as a multilocular cystic lesion with T2-hypointense septa separating compartments with variable T1 and T2 signals (indicating complex fluid content with a possible hemorrhagic component). It may also exhibit parietal or septal calcifications and mural nodules that enhance with CMI^[7,8^].

2. HCC in hepatopathy or cirrhosis: Key features favoring HCC include intense “wash-in” enhancement of the cyst wall, tumor nodules, or septa during the arterial phase, followed by “wash-out” compared to the non-tumor liver parenchyma in the portal phase.

3. Hemorrhagic biliary cyst: Suggested by the presence of mobile internal septa and/or non-enhancing pseudo-vegetations (due to their high fibrin content) after CMI.

4. LHC: MRI can better visualize the floating membrane, daughter vesicles, and peripheral rim (all with a T2-hypointense signal). However, diagnosing LHC can be difficult in the absence of typical radiological findings or a suggestive epidemiological context. Additionally, negative hydatid serology (occurring in 10% of cases) can further complicate the diagnosis[9].

5. Liver abscess: It may appear cystic, multilocular, and septated. The presence of gas bubbles within the lesion (19%) and pericystic contrast enhancement with a target or double-target pattern strongly suggests an infectious process[7].

As with our patient, percutaneous fine-needle aspiration biopsy (PFNAB) is often necessary for a definitive histopathological diagnosis in cases with uncertain etiology.

Conclusion

Characterizing a solitary LCM is often challenging. The main differential diagnosis revolves around HCCMs, which can be neoplastic or non-neoplastic. Establishing the etiology requires careful consideration of the patient’s age, gender, medical history, and clinical presentation. Although MRI plays a vital role in narrowing down the potential causes, PFNAB remains essential for a definitive diagnosis.

Radiologists should maintain a high index of suspicion for LCM to facilitate early diagnosis and prompt intervention. In addition, they should recognize that SCC can be a source of cystic liver metastases, necessitating investigation for a primary tumor if not already identified.

Ethical approval

As this manuscript is a single case report, we obtained written informed consent from the patient. Therefore, ethical approval was not sought, as it is not required for this type of publication according to our institutional guidelines.

Consent

Written informed consent was obtained from the patient for publication.

Sources of funding

None.

Author contributions

All authors approved the final draft submitted. This journal does not permit co-first authorship. It should also be stated that all authors have reviewed and approved the final manuscript, and that each author agrees to be held accountable for all aspects of the research. The work has been reported in line with the SCARE criteria.

Conflicts of interest disclosure

All authors declare that they have no conflict of interest.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Amine Chaabouni.

Provenance and peer review

Not commissioned; externally peer reviewed.

Data availability statement

None.

Patient’s perspective

The patient expressed feelings of anxiety and fear upon discovering a mysterious mass on his liver. The subsequent diagnosis of a rare cancer was devastating. He recounted the physical and emotional toll of chemotherapy while emphasizing the crucial role of support from healthcare providers and their personal network.