Multifocal desmoid-type fibromatosis (DTF) is very rare and usually regional. We report three cases that initially appeared to be multifocal, but subsequent detailed imaging revealed unsuspected tracking along nerves in two cases. This neural spread is reminiscent of neuromuscular choristoma (NMC), a rare developmental lesion in which mature skeletal muscle cells, or rarely smooth muscle cells, infiltrate and enlarge peripheral nerves. NMC is frequently associated with DTF. These two cases suggest that DTF spread along nerves and appeared as distinct multifocal lesions while actually being contiguous. The third case was felt to represent true multifocal tumor development, possibly due to tumor seeding at the time of chest surgery. The relationship of DTF to NMC is discussed.

BACKGROUND: Lipomatosis of nerve (LN) is a rare disorder characterized by the massive enlargement of peripheral nerves, frequently accompanied by generalized fibroadipose proliferation and skeletal overgrowth.
METHODS: The authors have been routinely following a 20-year-old male for lipomatosis of median nerve at the wrist noted shortly after birth. He had undergone resection of the lesion accompanied by sural nerve grafting at another institution. Clinically, although his neurological loss of function has been stable, he has had continued soft tissue growth. Serial magnetic resonance imaging has revealed persistent LN proximal to the repair sites with evidence of fatty proliferation in the sural grafts and continued LN and fatty proliferation distally. There has been a progressive circumferential pattern of fibrosis around the proximal and distal suture lines, which has a similar radiological pattern to desmoid type fibromatosis (a pattern recently described in neuromuscular choristoma [NMC] desmoid-type fibromatosis).
CONCLUSIONS: Considering the similar reaction of nerve in both LN and NMC despite differing genetic cascades, the authors believe a unifying process occurs in both lesions. The pattern of circumferential fibroproliferation would be most consistent with neuron-mediated growth from unspecified trophic factors, supporting a previously reported a nerve-derived \"inside-out mechanism.\" The clinical consequences of this unifying process are presented.

BACKGROUND: Neuromuscular choristoma (NMC) is a rare congenital lesion in which muscle tissue is admixed with nerve fascicles within a peripheral nerve. Patients commonly present in early childhood with neuropathy, plexopathy, or chronic undergrowth in the distribution of the affected nerve.
METHODS: The authors present the case of a 35-year-old man with unrecognized neuromuscular NMC of the sciatic nerve, which resulted in recurrent, multicentric NMC-associated desmoid-type fibromatosis (NMC-DTF) within the nerve territory in association with a Marjolin ulcer, a cutaneous malignancy.
CONCLUSIONS: Based on anatomical and pathophysiological findings described in this case report, the authors support the association between NMC-DTF and Marjolin ulcer.

OBJECTIVE: Benign triton tumors (BTTs) in the pediatric population are extremely rare occurrences. Paucity of data on BTTs poses both diagnostic and therapeutic challenges, particularly when found intracranially.
METHODS: A case report of a 10-year-old male diagnosed with incidental maxillary trigeminal (V2) BTT is presented. We discuss radiographic and histopathological interpretations. Furthermore, we provide a brief review of current literature and historical background on pediatric trigeminal BTT diagnosis, histopathology, and management.
RESULTS: Successful gross total resection of the tumor was achieved via Dolenc approach to the cavernous sinus. Management options with consideration of outcomes from the few prior cases reported in the literature are presented.
CONCLUSIONS: Treatment of trigeminal nerve tumors requires a broad differential diagnosis and understanding rare tumors is essential in the diagnosis and treatment algorithm.

Neuromuscular choristomas are rare tumors with mature skeletal muscle elements admixed with neural elements. Follow-up results are limited, the natural history of neuromuscular choristomas is poorly understood. To date, 14 cases of sciatic nerve neuromuscular choristomas have been reported, but follow-up results were provided only for 10 cases (median duration: 2 years). The natural history of neuromuscular choristomas is therefore poorly understood due to lack of longitudinal data. We describe a case with long-term natural history for 17 years of the disease and provide a literature review of the reported cases. A 6 year old girl, with a 6 year history of left buttock mass with neonatal pathologic diagnosis of neuromusculoar choristoma, presented with intermittent left lower extremity weakness in July 2006. She had a left buttock mass for 6 years, and the neonatal pathologic diagnosis was neuromuscular choristoma. Magnetic resonance imaging (MRI) revealed fusiform enlargement of the left sciatic nerve with mild enhancement similar to that of the muscle. The pathology of a re-biopsy sample was also consistent with neuromuscular. choristoma. In follow up, the mass increased slightly, but MRI findings remained consistent, and her condition remained stable for 11 years after re-biopsy. Aggressive fibrosis known as complication by manipulation of neuromuscular choristoma was also not developed. The patient has been followed up for a total of 17 years and this is the only case of long-term natural history of neuromuscular choristoma.

A 24-year-old male presented with eight months of increasingly severe frontal headaches, decreased right facial sensation, and periodic vertigo. Magnetic resonance imaging demonstrated a heterogeneously contrast-enhancing mass involving and expanding the right foramen ovale.  A biopsy of the lesion was performed, and the final pathologic diagnosis revealed a neoplastic rhabdomyoma. To date, only five cases of intracranial rhabdomyoma have been reported, and a rhabdomyoma involving the trigeminal nerve has never been described in an adult. This manuscript reviews the available literature and highlights the clinical, imaging, pathologic characteristics, and surgical management of these exceedingly rare lesions.

BACKGROUND: Neuromuscular hamartoma, also known as neuromuscular choristoma or benign triton tumor, is a rare benign tumor of well-differentiated striated muscle fibers mixed with peripheral nerve fibers. According to our research, this is the sixth case of benign triton tumor of the trigeminal nerve and the third case of isolated orbital location reported in the world literature.
OBJECTIVE: To report a rare case of orbital neuromuscular hamartoma and discuss the role of corticosteroids in the treatment of these lesions for which surgical excision is often difficult.
METHODS: A 47-year-old woman, with a history of tuberculous lymphadenitis treated in 2006, presented with a clinical scenario of inflammatory orbitopathy without loss of visual acuity progressing over 20 days. MRI showed a lesion centered on the soft tissues of the infero-lateral right orbit. A biopsy was performed, showing neuromuscular hamartoma on histology. The patient was put on a tapering dose of corticosteroids with clear clinical and anatomical improvement. Orbital CT follow-up was obtained two months after discontinuation of treatment, confirming the disappearance of the tumor mass.
CONCLUSIONS: Hamartoma of the orbit is a very rare entity and may clinically simulate malignant neoplasms; the diagnosis is histologic. Given the difficulties encountered in the resection of these tumors, we believe that corticosteroids might be proposed as an alternative treatment that could modulate inflammation and bring about regression or disappearance of the tumor.

BACKGROUND: Neuromuscular hamartomas are rare benign tumors with mature skeletal elements mixed with mature neural elements. They present typically as solitary lesions in childhood and have been reported to be associated with cranial nerves or large peripheral nerves such as the brachial plexus, median nerve, and sciatic nerve. To date, eight cases of sciatic nerve neuromuscular hamartomas have been reported. We present a case along with an outline for the natural history of the disease with a review of the literature of the reported cases dating back to 1895.
METHODS: An 11-year-old boy presented with progressive right lower extremity pain and atrophy. Magnetic resonance imaging revealed a large right sciatic nerve mass, and electromyography demonstrated evidence of ongoing denervation and reinnervation. Initial computed tomography-guided biopsy was unrevealing and subsequent open biopsy was consistent with neuromuscular choristoma.
CONCLUSIONS: Neuromuscular choristomas represent a rare disease. Symptoms of foot deformity, leg size discrepancy, and pain merit a complete work-up including spinal and peripheral nerve etiologies.