Nested stromal-epithelial tumour of the liver: An unusual liver entity

Calcifying Nested Stromal-Epithelial Tumor: An Extremely Rare Hepatic Tumor

Calcifying nested stromal-epithelial tumor is a rare hepatic malignancy with approximately 50 cases reported in the literature. Its clinical presentation is nonspecific, and the diagnosis is mainly based on histology which shows nests of spindle and epithelioid cells along with a desmoplastic myofibroblastic stroma containing variable calcification and ossification. In this report, we present a case of a 24-year-old woman with a history of abdominal pain, distension, and dyspepsia. She had a palpable liver with normal liver function test results. Serum alpha-fetoprotein levels were within normal range, and serologies for hepatitis B and C virus remained negative. Radiological investigations (magnetic resonance imaging and computed tomography) showed a large, right hepatic lobe mass with tumor invasion into the right posterior portal vein, but the 2 modalities could not characterize the lesion. Finally, an ultrasound-guided biopsy of the liver lesion provided the diagnosis of calcifying nested stromal-epithelial tumor. The tumor was resected successfully.

Liver Transplantation for Unresectable Calcifying Nested Stromal Epithelial Tumor: Case Report With a 1-Year Follow-Up and Review of Literature

Introduction

Calcifying nested stromal epithelial tumor (CNSET) is an extremely rare diagnosis among patients treated for primary hepatic neoplasms. There are only 45 cases reported worldwide. Histopathological characteristics are well-demarcated nests of spindle and epithelioid cells in a dense desmoplastic stroma with variable calcification and ossification. It is mostly diagnosed in children and young females. Treatment strategies implemented for the management of CNSET include radiofrequency ablation, transarterial chemoembolization, surgical resection, adjuvant and neoadjuvant chemotherapy, and liver transplantation. Given the small number of available cases, there are still no established standards of treatment for this neoplasm.

Case Presentation

A 28-year-old female diagnosed with CNSET presented mild abdominal pain, with normal laboratory values. The tumor was initially deemed unresectable, therefore, the patient was disqualified from liver resection. Further deterioration of the patient's clinical condition and local tumor progression led to qualification for liver transplantation. The patient underwent liver transplantation 1 year following initial diagnosis and a 12 months recurrence-free period was observed. During the course of treatment, she did not receive systemic chemotherapy, radiotherapy, or loco-regional treatment.

Conclusion

Multiple strategies have been implemented for the treatment of CNSET, with liver resection providing the best outcomes. Transarterial chemoembolization, radiofrequency ablation, and radiotherapy are reported to be insufficient in the management of this tumor. Various chemotherapy regimens turned out to be ineffective as well. There have been only eight reported cases of patients undergoing liver transplantation for CNSET, with tumor recurrence in two cases. CNSET appears to be a neoplasm with low malignancy potential, although an aggressive progression has subsequently been reported. Further investigation is still required in this field.

Nested Stromal-Epithelial Tumor of the Liver: A Review

BACKGROUND

Nested stromal-epithelial tumor (NSET) is a rare liver tumor, which is most commonly seen in the pediatric age group. To the best of our knowledge, there has been no published review on this rare tumor in the English literature so far.

SUMMARY

In this review, we will discuss all the reported details of the published cases, including demography, clinical presentation, molecular histogenesis, imaging, gross pathology and histopathology, immunohistochemical findings, treatment modalities, and outcome of NSET of the liver.

KEY MESSAGE

Thirty-eight cases of NSET have been reported in the last 20 years in the English literature. This tumor produces a very large and calcified mass in the liver and characteristically can present as Cushing syndrome. NSET is a nonbiliary and nonhepatocytic tumor with biphasic differentiation into 2 components of epithelial and stromal cells. The epithelial cells are arranged as nests of mildly atypical epithelial cells with a few mitotic figures. The stromal component is composed of myofibroblasts and desmoplastic stroma which often shows ossification and calcification. Immunohistochemically, this tumor is positive for both epithelial and mesenchymal markers. The majority of the reported cases in the literature had benign behavior with an indolent course.

Calcifying Nested Stromal-Epithelial Tumor of the Liver: An Update and Literature Review

Calcifying nested stromal-epithelial tumor is a rare entity that has gone by a variety of names in the literature: ossifying malignant mixed epithelial and stromal tumor, ossifying stromal-epithelial tumor, and desmoplastic nested spindle cell tumor of the liver. To our knowledge, approximately 38 cases have been reported in the literature. The histogenesis is still largely unknown but histopathologically is characterized by nests of spindle and epithelioid cells in an organoid arrangement surrounded by a prominent dense myofibroblastic stroma with occasional psammomatous calcification and focal heterotopic ossification. Vascular invasion is rare and tumoral recurrence is uncommon with only a single reported case of metastasis leading to death. Treatment is mainly by surgical intervention with the role of chemotherapy seeming limited, but lack of data hinders a true recommendation. It is important to rule out other processes such as hepatoblastoma, calcified hemangioma, synovial sarcoma, metastatic gastrointestinal stromal tumor, desmoplastic small round cell tumor, among others, which appear similar radiographically and histopathologically.

Calcifying nested stromal epithelial tumor of the liver in a patient with Klinefelter syndrome: a case report and review of the literature

BACKGROUND

Calcifying nested stromal epithelial tumor (CNSET) is a primary neoplasm of the liver, characterized by well-demarcated nests consisting of spindle and epithelioid cells with calcification and bone formation. An association of Cushing syndrome with CNSET has drawn attention, but the origin of CNSET has not been clarified.

CASE PRESENTATION

We report here the case of a 20-year-old male with Klinefelter syndrome who underwent liver resection for an increasing liver tumor that was pathologically diagnosed with CNSET. He was postoperatively followed up and received several examinations, and recurrences and extrahepatic lymph node metastases were detected on the 64th day after surgery. Chemoembolization and chemotherapy were not effective, leading to tumor progression with development of progressive liver failure, and the patient finally died 164 days after hepatectomy.

CONCLUSIONS

This case suggests that an imbalance of hormones affects the genesis and progression of CNSET, and indicates the importance of closely following patients with CNSET by imaging with attention to hepatic recurrence and extrahepatic metastases.

A Rare Nonhepatocytic Primary Liver Neoplasm with an Unusual Presentation: Ossifying Malignant Mixed Epithelial and Stromal Tumor

We present a case of a rare liver neoplasm – Ossifyimg malignant mixed epithelial and stromal tumor. This entity has well-delineated morphological and immunohistochemical features, and so can be easily diagnosed, even with core biopsy tissue. Our patient was a middle-aged male, which is unheard of in the literature of this disease. He had a bad recurrence of the disease after surgical removal of the tumor, unlike the previously reported cases with the same diagnosis, where the patients lived for almost a decade after surgery without recurrence. This neoplasticdisease can thus take a destructive course, and a change in treatment methods such as neoadjuvant or adjuvant chemotherapy should be thought of, to make it more beneficial and effective.

Are liver nested stromal epithelial tumors always low aggressive?

Nested stromal-epithelial tumor (NSET) is a non-hepatocytic and non-biliary tumor of the liver consisting of nests of epithelial and spindled cells with associated myofibroblastic stroma and variable intra-lesional calcification and ossification, which represents a very rare and challenging disease. Most of the reported cases have been treated with surgery, obtaining a long survival outcome. Here, we report the case of a 31-year-old Caucasian man who underwent surgery at our institution for a large, lobulated, multinodular mass of the right hemi-liver. The histological exam confirmed the diagnosis of NSET. After 6 mo from surgery, a liver recurrence was described and a chemo-embolization was performed. After a further disease progression, based on the correlation between the histological features of the disease and those of the hepatoblastoma, a similar chemotherapy regimen (with cisplatin and ifosfamide/mesna chemotherapy, omitting doxorubicin due to liver impairment) was administered. However, infection of the biliary catheter required a dose modification of the treatment. No benefit was noted and a progression of disease was radiologically assessed after only four cycles. The worsening of the clinical status prevented further treatments, and the patient died a few months later. This case report documents how the NSET might have an aggressive and non-preventable behavior. No chemotherapy schedules with a proved efficacy are available, and new data are needed to shed light on this rare neoplasm.

Desmoplastic nested spindle cell tumours and nested stromal epithelial tumours of the liver

Desmoplastic nested spindle cell tumour of liver (DNSTL), nested stromal-epithelial tumour (NSET) and calcifying nested stromal-epithelial tumour (CNSET) are recently described entities with similar morphology, immunohistochemistry and molecular genetics. These are rare entities with only three large case series described till date. These tumours commonly present in the paediatric age group. NSETs, in addition have been described to be associated with ectopic adrenocorticotropic hormone (ACTH) production and Cushingoid features. It is important to discuss this rare group of tumours with a low malignant potential as the most common radiological differential diagnosis is hepatoblastoma, which has a relatively poorer prognosis. Thus, a pathologist needs to keep this entity in mind, so as to offer a correct histological diagnosis.

Calcifying nested stromal-epithelial tumor (CNSET) of the liver: a newly recognized entity to be considered in the radiologist's differential diagnosis

Calcifying nested stromal-epithelial tumor (CNSET), an extremely rare tumor found in the liver, was first described in 2001 by Ishak et al. The characteristic imaging features include large size, well-circumscribed, enhancing mass with calcification. To our knowledge, since 2001, there have been 29 reported. Typically arising from the right hepatic lobe, it is primarily found in children and shows clear predilection for females. Emphasizing imaging, we report a 14-year-old female with Beckwith-Wiedemann syndrome who presented with CNSET.