Case report: Concurrent malignant triton tumor and relapsed pituitary adenoma in the sellar region

Primary hepatic malignant triton tumor mimicking hepatocellular carcinoma by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging: a case report and literature review

Background

Malignant Triton tumor (MTT) is a relatively rare subtype of malignant peripheral nerve sheath tumor (MPNST) characterized by rhabdomyosarcoma differentiation. There are no distinct features of MTT, and it is easy to misdiagnose preoperatively.

Case presentation

Here, we describe a rare case of primary hepatic MTT in a 56-year-old male who presented with nonspecific abdominal pain for 1 day. Magnetic resonance imaging and abdominal computed tomography revealed an extremely large mass located in the right liver with intratumoral hemorrhage, arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging and the possibility of intrahepatic metastasis. Tumor marker levels revealed only an elevated level of alpha-fetoprotein (AFP: 5304.0 ng/mL). Then, he received transcatheter arterial chemoembolization combined with lenvatinib and pembrolizumab, and he was diagnosed with hepatocellular carcinoma. After 3 months of neoadjuvant therapy, we resected the hepatic cancer and adherent diaphragmatic pleura. MTT was confirmed by postoperative pathology and immunohistochemistry.

Conclusion

Despite the preoperative diagnosis of hepatocellular carcinoma with a rising serum AFP level, typical CT and MRI findings, histopathology assessment showing MPNST with rhabdomyosarcoma differentiation confirms the diagnosis of primary hepatic MTT.

Malignant triton tumor of uterus: A case report and literature review

Malignant triton tumor (MTT) is a highly aggressive malignant neoplasm, classified as a variant of malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. There are few reports that MTT occurred in urogenital system. In the present study, we report the first MTT occurring in the uterus. A 57-year-old woman came to the emergency department due to persistent vaginal bleeding for 2 months. The gynecological palpation found that a club-shaped excrescence existed in the vagina about 7 cm × 3 cm × 3 cm. The mass located in the lower segment of the uterus and the cervix was confirmed by gynecological vaginal ultrasound and magnetic resonance imaging, which was preliminarily diagnosed as cervical carcinoma. After neoplasm punch biopsy, the pathological diagnosis was malignant triton tumor. The patient finally lost follow-up. This is the first report about MTT in the uterus and suggests that pathological biopsy combined with imaging examination is necessary for the diagnosis of rarely MTT.

Clinical diagnostic and radiographic features of recurrent intracranial malignant triton tumor in an adult: illustrative case

BACKGROUND

Malignant triton tumors (MTTs) are a rare and aggressive type of malignant peripheral nerve sheath tumor identified histologically by focal rhabdomyoblastic differentiation.

OBSERVATIONS

A 37-year-old female with a prior history of Hodgkin lymphoma presented with acute-onset confusion, cognitive deficits, and weakness. Brain magnetic resonance imaging revealed a hemorrhagic intracranial mass later confirmed to be a malignant triton tumor. The patient underwent two resections and several courses of chemoradiation for multiple tumor recurrences and metastases. Unfortunately, despite extensive treatment, she died 2 years after initial presentation from complications of this tumor. Her overall survival (OS) of 26.7 months was double that reported in historical cohorts (OS ∼13 mos).

LESSONS

The diagnosis and treatment of central nervous system MTTs are difficult and require a multidisciplinary team of neurosurgeons, radiologists, and oncologists. Histopathological analysis is required for confirmation of diagnosis. Gross-total resection of tumor and adjuvant radiation therapy have been shown to give patients the highest rates of survival and improved outcomes. Further studies and clinical trials are warranted to investigate the efficacy of chemotherapeutic agents like temozolomide, bevacizumab, and abemaciclib.