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

Tomas Marek, Mark A. Mahan, Kimberly K. Amrami, Patrick R. Blackburn, Patricia L. Caffes, Jodi M. Carter, Michael Camilleri, Robert J. Spinner

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


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.

Original languageEnglish (US)
Article numbere13917
JournalNeurogastroenterology and Motility
Issue number10
StatePublished - Oct 1 2020


  • PIK3CA
  • diverticular disease
  • fibrolipomatous hamartoma
  • lipomatosis of nerve
  • sciatic nerve

ASJC Scopus subject areas

  • Physiology
  • Endocrine and Autonomic Systems
  • Gastroenterology


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