Decompression and collagen wrapping of a fibrolipomatous hamartoma of the median nerve: a new approach for a rare and difficult problem

Fibrolipomatous hamartoma is a rare benign slow growing fibrofatty tumor of peripheral nerves of unknown etiology. Clinical presentation may mimic carpal tunnel syndrome when involving the median nerve. We present a case of FLH of the median nerve in a 59-year-old female treated with decompression and collagen nerve wrapping.

Exuberant circumferential fibroproliferative neuromas in lipomatosis of nerve: a unifying theory. Illustrative case

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.

OBSERVATIONS

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).

LESSONS

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.

Unrecognized sciatic lipomatosis of the nerve diagnosed by telehealth: illustrative case

BACKGROUND

Lipomatosis of the nerve (LN) is a rare congenital hamartoma in which abundant fibroadipose tissue is found within the epineurium of peripheral nerves. It is frequently associated with nerve territory overgrowth affecting bones or soft tissues. The clinicoradiological features are well known and pathognomonic.

OBSERVATIONS

A 38-year-old female was evaluated via telehealth for worsened sciatica after the resection of a sciatic notch lipoma, after having been evaluated over a decade for symptoms. Virtual physical examination revealed previously unrecognized subtle limb discrepancy (i.e., overgrowth). Although preoperative radiographs were unavailable during the initial evaluation, postoperative magnetic resonance imaging studies showed evidence of sciatic nerve LN. A diagnosis of LN and nerve territory overgrowth was established.

LESSONS

Despite its limitations, telehealth can be an effective alternative or adjunct to in-person evaluations in making complex diagnoses. Dedicated examination without clinical suspicion can miss subtle findings. An iterative process prompted by a focused history, knowledge of clinical associations, and pattern recognition can facilitate an accurate diagnosis without obvious face-to-face visual clues. In patients with rare disorders, asynchronous evaluation allows in-person visits to be supplemented by subsequent telehealth virtual physical exam findings. This case illustrates how examination via telehealth can be used to effectively diagnose a rare syndrome.

Trigeminal Lipomatosis: A Rare Cause of Intractable Neuralgia

Lipomatosis of nerve, earlier known as fibrolipomatous hamartoma is a rare condition which predominantly affects peripheral nerves, cranial nerve involvement being extremely uncommon. Preoperative consideration of this entity is of paramount importance as its inadvertent complete surgical resection may inevitably result in significant neurological deficit. We report a case of trigeminal lipomatosis in a young patient with trigeminal neuralgia.

Occult lipomatosis of the nerve as part of macrodystrophia lipomatosa: illustrative case

BACKGROUND

Macrodystrophia lipomatosa (MDL) is characterized by progressive overgrowth affecting soft tissues and bony structures and is part of lipomatous overgrowth syndromes. MDL has been associated with lipomatosis of the nerve (LN), an adipose lesion of nerve that has a pathognomonic magnetic resonance imaging (MRI) appearance as well as a mutation in the PIK3CA gene. The authors present a case of occult LN in the setting of MDL.

OBSERVATIONS

A 2-year-old boy with progressive soft tissue overgrowth of his proximal right lower extremity was initially diagnosed with neurofibromatosis type 1 (NF1). At our institution, NF1 as well as other overgrowth syndromes including PTEN hamartoma tumor syndrome were excluded. He was diagnosed as having so-called MDL. Upon reinterpretation of the patient's MRI studies, short-segment LN involving the proximal sciatic nerve and part of lumbosacral plexus was identified. He underwent 2 debulking/liposuction procedures for soft tissue overgrowth. Genetic testing of tissue revealed a mutation in PIK3CA.

LESSONS

Thorough clinical examination (for signs of overgrowth) as well as an MRI study of the entire neural pathway is a critical part of the diagnostic workup to evaluate for LN. The authors believe that an increasing association of LN, even when occult, will emerge that will explain many cases with marked nerve-territory overgrowth.

Fibrolipomatous Hamartoma Arising from the Median Nerve-A Case Report

Fibrolipomatous hamartoma is a rare nonhereditary, congenital condition characterized by benign hyperplasia of fibroadipose tissue around nerve bundles. The median nerve is commonly affected. Underlying pathological process is mature adipose and fibrous tissue infiltrating the epineural and perineural compartments giving typical "pseudo-onion bulb" appearance on histology and "coaxial cable" appearance on magnetic resonance imaging (MRI). This case of fibrolipomatous hamartoma well illustrates its characteristic clinical, radiological, and histopathological features. Patient is a teenage female presented with painless gradually enlarging mobile lump in the central left palm. Ultrasound scan revealed a hyperechoic subcutaneous lesion, with intervening fine hypoechoic cable like structures following the course of median nerve which was thickened. Computed tomography (CT) confirmed thickened left median nerve with radiating isodense fascicles surrounded by fatty areas. There were no calcifications. MRI showed classic "coaxial cable" like T1, T2 isointense fascicles continuous with the median nerve surrounded by a fusiform lesion demonstrating fat signals on spin-echo sequences which dropped on fat-suppressed gradient echo sequences. Diagnosis of fibrolipomatous hamartoma arising from left median nerve was made, based on typical imaging findings. Biopsy confirmed fibrolipomatous hamartoma. Diagnosis can be made confidently on imaging alone especially with MRI, without the need of biopsy. Both CT and MRI demonstrate fatty mass encasing the thickened nerve fibers. On MRI, characteristic appearance is seen as T1 and T2 low intense tubular thickened neural bundles surrounded by high signal fatty tissue.

Carpal Tunnel Syndrome Secondary to Fibrolipomatous Hamartoma of the Median Nerve

Fibrolipomatous hamartoma (FLH) is a rare, benign neoplasm that affects the median nerve predominantly and can present with compressive symptoms. MRI can be used to diagnose this condition without the need for a nerve biopsy. While no definitive treatment has been described, open carpal tunnel release for nerve decompression is currently the standard of care to alleviate compressive neuropathies of the median nerve. In this report, we describe a case of FLH diagnosed via MRI in which the patient's symptoms responded to open carpal tunnel release.

Fibrolipomatous Hamartoma of the Median Nerve: An Outcome of Surgical Management in Six Consecutive Cases

Background

Lipoma is a nonneurogenic benign tumor. Neurolipoma and fibrolipomatous hamartoma are variants of this universal tumor. All these variants are grouped under lipomatosis of the nerve. Majority of these tumors are asymptomatic, which can be observed. Symptomatic patients require surgery, which is not standardized. As there are insufficient number of cases, no randomized controlled studies have been performed in the treatment of fibrolipomatous hamartoma. The aim of our study was to determine the pattern of presentation of fibrolipomatous hamartoma, surgical management offered, and the outcome in the form of recovery and complications.

Materials and Methods

This retrospective descriptive study includes six patients diagnosed with fibrolipomatous hamartoma over a period of 12 years. Patient details were collected from the medical records. Patients diagnosed of fibrolipomatous hamartoma in the hand were included. Patients with other soft-tissue tumors were excluded from the study. Out of six patients, four required excision of nerve followed by reconstruction using sural nerve graft and two underwent microsurgical dissection of neural element. Patients were instructed to take care of the operated hand during the recovery phase. Institutional physiotherapy protocol was started during the 3^rd postoperative week. Follow-up period was between 1 and 3 years.

Results

All the six patients were free from symptoms postoperatively. Minimal complications were noted in two patients, which were managed conservatively.

Conclusion

Surgical excision of fibrolipomatous hamartoma of median nerve below elbow, with nerve dissection or with nerve reconstruction using sural nerve graft, followed by proper postoperative care and physiotherapy has proven beneficial for the patients in our study.

Expanding the phenotypic spectrum of lipomatosis of the sciatic nerve: Early-onset colonic diverticular disease

BACKGROUND

Lipomatosis of nerve (LN) is a complex peripheral nerve disorder characterized by fibrofatty nerve enlargement. MRI of this pathology is pathognomonic and obviates a diagnostic biopsy. Mutation in PIK3CA has been associated with LN cases with nerve-territory overgrowth which may occur in some cases. We evaluate an association of LN of the sciatic nerve and early-onset colonic diverticular disease and discuss the potential pathogenesis.

METHODS

Our institutional database was searched for LN cases. Available information of identified cases was reviewed, and cases with a confirmed diagnosis of LN affecting the lumbosacral plexus and/or sciatic nerve; available MRI of the affected nerve(s); and diverticular disease occurring in the area supplied by the nerve(s) affected by LN were further analyzed. PIK3CA mutation testing was performed on available tissue samples.

RESULTS

We identified 10 LN cases of lumbosacral plexus and/or sciatic nerve. Of these, three fulfilled our inclusion criteria. All three patients had concomitant colonic diverticular disease, diagnosed at a relatively young age. MRI studies of these cases showed LN involvement of the sacral nerves innervating the sigmoid colon. All three also had abnormal diagnostic workup including various GI tests and evidence of associated nerve-territory overgrowth. Colonic tissue samples for PIK3CA mutation were negative.

CONCLUSION

While the pathogenesis of the colonic diverticular disease is increasingly recognized as being multifactorial, our observations are consistent with the potential role of autonomic nervous system dysfunction affecting either the pelvic floor musculature, or the colon itself (or both) in a subset of patients with early-onset diverticular disease.

Tingling hand: magnetic resonance imaging of median nerve pathologies within the carpal tunnel

Compressive neuropathy of the median nerve at the level of the carpal tunnel, known as carpal tunnel syndrome, is the most common entrapment neuropathy, affecting about 0.1-1% of the general population. Magnetic resonance reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. Magnetic resonance imaging (MRI) serves as an extremely useful tool for evaluation of primary nerve pathologies and for the assessment of space-occupying lesions leading to its compression. We present a pictorial review of the MRI findings in the multitude of pathologies implicated in the causation of carpal tunnel syndrome. All the images were obtained from the Department of Radiodiagnosis in our own institution.

A Clear Mystery: Recognizing Lipomatosis of the Nerve

Lipomatosis of the nerve (LN) commonly presents with neurologic dysfunction due to massive fibro-fatty enlargement of the peripheral nerves. It is uniquely associated with adipose proliferation in the subcutaneous tissue and muscle in the innervated territory, along with osseous abnormalities. Herein, we present the case of a 56-year-old woman who presented with severe right ulnar distribution pain involving the medial forearm and hand (9/10 on a numerical rating scale), declining right-hand strength, movement-dependent hypoesthesias, paresthesias, and a pronounced claw deformity of the right hand with intrinsic atrophy. Electrodiagnostic studies demonstrated pronounced fibrillations, decreased voluntary activation, and minimal collateral reinnervation in the abductor digiti minimi and abductor pollicis brevis, consistent with dysfunction of the lower trunk of the right brachial plexus. Magnetic resonance imaging (MRI) and computed tomography (CT) of the brachial plexus were interpreted as a tumor on the right supra- and infraclavicular brachial plexus. At surgery, the brachial plexus was embedded in relatively tight connective tissue with a typical lipoma posteriorly. The lipoma was resected, and the plexus was explored extensively. This case is the 10th report of LN involving the brachial plexus and demonstrated the cardinal features of LN. It provides insight into the pattern of lesions associated with innervation by LN.

Giant Median Nerve Due to Hamartoma Causing Severe Carpal Tunnel Syndrome

Introduction:

Lipofibromatous hamartoma (LFH) is a very rare, benign, slow-growing peripheral nerve tumor.

Case Report:

We present a case of LFH of the median nerve, which caused enlargement of the median nerve and the digital branches in a young male, and was treated surgically. Our treatment choice was resection of large portions of the fibrofatty tissue and decompression of the carpal tunnel.

Conclusion:

A high index of suspicion for LFH is crucial in patients presenting with painless masses combined with acute compression neuropathy.

Precalcaneal congenital fibrolipomatous hamartoma: Rare or under-reported?

Precalcaneal congenital fibrolipomatous hamartoma (PCFH) is a benign under-reported condition of infancy characterized by the presence of soft nodules on precalcaneal plantar surface of the heel. These lesions are usually bilateral solitary and asymptomatic. We present a 2-month-old infant with solitary skin-colored nodules present on precalcaneal plantar aspect of bilateral heels.

Fibrolipomatous Hamartoma of the Median Nerve with Macrodystrophia Lipomatosa

Fibrolipomatous hamartoma (FLH) is a rare congenital condition that presents with a benign overgrowth of the bone and fibroadipose tissue termed as macrodystrophia lipomatosa (MDL). Although commonly seen in the median nerve, other peripheral nerves can be involved. Diagnosis can be made on magnetic resonance imaging (MRI) due to the characteristic coaxial cable appearance on axial images and the spaghetti appearance on sagittal images. Histology shows mature adipose and fibrous tissue infiltrating the epineural and perineural compartments. Multiple or debulking surgeries are often needed, with an emphasis on cosmetic aspects. We present one such case in which wide margin excision and sural nerve graft were carried out.

Nasal Fibrolipomatous Hamartoma, an Idiosyncratic Connective Tissue Malformation in an Infant

We describe a congenital mass in the nasopharynx of an infant presenting with dyspnea and feeding difficulties. Magnetic resonance imaging demonstrated 2 separate polypoid nasal cavity masses that were endoscopically resected. Histologically, both lesions were composed of mature adipose tissue with broad fibrous bands and several foci of brown fat. PLAG-1 and HMGA-2 were negative by immunostains. The best diagnosis was a fibrolipomatous hamartoma.

Neural Fibrolipoma of the Ankle: A Case Report and Review of the Literature

Neural fibrolipomas are exceedingly rare benign tumors composed of hypertrophied fibrofatty tissue intermixed with nerve tissues. Our review of the published data identified only 15 cases of this tumor involving the foot and/or ankle region. An otherwise healthy 35-year-old male was referred for evaluation of a painless soft tissue mass present in the anterior left ankle. The mass had been present for approximately 6 to 7 years and had recently increased in size. Physical examination demonstrated a prominent, fluctuant mass present in the left ankle measuring 4 cm in diameter. The mass was not well-defined, was immobile, and did not transilluminate. No gross pedal deformity was present. Radiographic imaging revealed increased soft tissue prominence and density to the anterior ankle without bone involvement. Magnetic resonance imaging demonstrated a mass isointense to fat on all sequences without contrast enhancement, suggestive of a lipoma. Surgical excision was performed; the mass was yellow and lipomatous in nature. The mass was intimately associated with the superficial peroneal nerve, which had to be sacrificed during excision. The pathologic examination of the mass revealed findings consistent with a neural fibrolipoma. The patient healed uneventfully without recurrence. His only complaint was of some residual numbness in the medial foot.

Evaluation and management of fibrofatty tumors of the extremities: case report

Patients presenting with enlarging fibrofatty masses in the extremities pose an interesting dilemma to clinicians, as the differential diagnosis in such cases ranges from benign to malignant, and from lesions optimally managed operatively to those managed nonoperatively. The differential diagnosis includes benign lipoma, liposarcoma, lipoblastoma, and fibrolipomatous hamartoma (lipomatosis) of the nerves. The authors present the case of a 14-year-old girl with an enlarging fibrofatty mass of the forearm, initially thought, based on diagnostic imaging, to be a fibrolipomatous hamartoma of the median nerve, but found to be a lipoblastoma without direct nerve involvement based on histopathological examination of the operative specimen. This case serves to illustrate the diagnostic predicament that can exist with such masses. The authors advocate the need to establish a tissue diagnosis while having a contingency plan for each of the diagnostic possibilities because the management of each lesion is markedly different. In this report, the authors consider the differential diagnosis of fibrofatty masses of the extremities that the peripheral nerve surgeon may encounter, and they highlight the significant differences in management strategies for each possible diagnosis.

Fibrolipomatous hamartoma of the median nerve in the elbow: a case report

A fibrolipomatous hamartoma-also known as a fibrofatty overgrowth, perineural lipoma, intraneural lipoma, and lipomatous hamartoma-is a rare, benign, congenital lesion most commonly found in the median nerve, usually at the level of the wrist or hand. To our knowledge, no published cases report a hamartoma arising from the median nerve at the level of the elbow. We report a case of a fibrolipomatous hamartoma in a 55-year-old woman that necessitated a surgical intervention because of its size and associated neurologic symptoms.