Malignant Glandular Triton Tumor Arising in the Radial Nerve with Prolonged Survival: A Case Report and Review of the Literature

Abstract

Divergent differentiation is a well-known phenomenon in malignant peripheral nerve sheath tumors (MPNST) which occurs approximately in 15% of these tumors, usually towards mesenchymal elements. Differentiation towards epithelial components, however, is quite uncommon, and even exceptionally rare is concomitant mesenchymal and glandular differentiation. To our knowledge, only 14 cases of MPNST with both mesenchymal (rhabdomyoblastic) and glandular differentiation had been reported, and only two of these tumors had frankly malignant glandular components. Herein, we report the third such case. A 26-year-old male, without any of the stigmata of NF1, presented with a 2-year history of pain in his left shoulder and an elbow swelling of six-month duration. The tumor was initially diagnosed clinically as a neurofibroma at a local hospital. The patient underwent excision of the mass there, and pathological examination at that hospital showed the tumor to be MPNST. Six months later, the patient was referred to our hospital, a tertiary care medical center, with recurrent swelling at the same location. Histopathological material from the referral hospital was reviewed, and the tumor was diagnosed as MPNST with rhabdomyoblastic differentiation or malignant triton tumor (MTT) that contained in addition foci of malignant glandular epithelium. The patient refused any surgical intervention. He received three cycles of chemotherapy followed by radiotherapy with excellent response and marked reduction in the size of the tumor. The patient had prolonged survival for 10 years following the initial resection of the tumor.

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

“…A range of cases presentation in the literature we reviewed describe the imaging manifestations (including CT and MRI) correlated with MTT: giant lump, heterogeneity, irregular margins, intratumoral hemorrhage, necrosis, lobulation, calcifications, heterogenous enhancement on postcontrast CT or MRI, hypointense/isointense T1WI and hyperintense T2WI signal on MRI, and diffusion restriction on DWI and ADC 1,8–32,39,40 . Zain et al 20 and Li et al 29 had reported similar conclusions, Li et al pointed out some characteristics common to MTTs and MPNSTs, including ill‐defined margin, intratumoral lobulation, peripheral edema, calcifications, and destruction of adjacent bone tissues.…”

“…We compiled data on reported cases of MTT in the recent 6 years (2018–2023, Table 1). 1,6–38 There were totally 37 cases with a mean age of 39.4 years (range 8 months old–75 years old), including 24 male and 13 female patients. Eleven cases originated in the abdomen (30%), 10 cases in the head and neck (27%), 8 cases in the thoracic cavity (21%), 6 cases in the limbs (16%), 1 case in the spine (3%), and 1 case in the buttocks (3%).…”

Benign glandular schwannoma

“…Only a few reports have described such occurrences and suggested different hypotheses. [12][13][14] The glandular elements have been suggested to originate from skin entrapment. 15 Other potential reasons behind the origin of these glandular structures is metaplasia 11 or the glands being induced by the tumor from pluripotential neural crest cells rather than being entrapped.…”