A Vasculitis-Associated Neuromuscular and Vascular Hamartoma Presenting as a Fatal Form of Abdominal Cocoon

Neuromuscular and Vascular Hamartoma: Starting Point in Crohn's Disease?

Neuromuscular and vascular hamartoma (NMVH) is a benign and rare lesion comprising abnormal proliferation of cellular elements in the mucosa of the small intestine. NMVH shares certain histological features with inflammatory conditions like Crohn’s disease, radiation and ischemic enteritis, and has been a part of ongoing debate since it was first described in 1982. We intend to describe an interesting case of small bowel obstruction caused by NMVH and emphasize the importance of keeping it as an important differential diagnosis in cases of small bowel obstructions for general practitioners and gastroenterologists. After detailed analysis of the 28 cases of the NMVH in the literature we are also suggesting NMVH as a starting point in Crohn’s disease, and if proven it will change the management strategies for Crohn’s disease.

ANCA-associated vasculitis with protein-losing enteropathy is characterized by hypocomplementemia

Protein-losing enteropathy (PLE) has been reported to be associated with various systemic autoimmune diseases. However, reports regarding PLE in ANCA-associated vasculitis (AAV) patients are limited. We herein aimed to describe the clinical characteristics of AAV with PLE. We conducted a retrospective chart review of patients who were diagnosed with AAV and who began treatment at the University of Tokyo Hospital between June 2003 and June 2020. Among 68 AAV patients, there were four patients (5.9%) with PLE, consisting of two patients with MPA, one patient with GPA, and one patient with EGPA. Clinical courses were described, and their data were compared with AAV patients without PLE. Demographic characteristics, disease activity, and the pattern of organ involvement were similar between patients with PLE and without PLE. Patients with PLE had hypocomplementemia more frequently than the patients without PLE (CH50 75.0% vs 1.8%, p < 0.001, C3 50.0% vs 1.8%, p = 0.01, C4 75.0% vs 3.5%, p = 0.001). Although hypoalbuminemia improved with immunosuppressive therapy for AAV, the improvement in hypoalbuminemia was slow in most cases. We also performed a systematic review on PLE associated with vasculitis. Thirteen reports were included, and Henoch-Schonlein Purpura patients with PLE also tended to have hypocomplementemia. In conclusion, PLE is a rare complication of AAV and complement system may associate with the mechanism of PLE.

An extremely rare case of neuromuscular and vascular hamartoma of the appendix

Background

Neuromuscular and vascular hamartoma is a rare lesion of the small intestine, with only 26 cases reported since its initial description in 1982. No occurrence of hamartoma in the appendix has been reported until now.

Case presentation

A 60-year-old man had been suffering from longstanding right lower quadrant pain. Abdominal computed tomography showed a slight swelling of the appendix as the possible cause of his pain. Laparoscopic appendectomy with partial resection of the cecum was performed for diagnostic and therapeutic purposes. An 18 × 10-mm lesion located on the tip of the appendix was found in the resected specimen. Pathological examination showed that the lesion was covered with normal mucosa and consisted of adipose tissue, smooth muscle fibers, small vessels, and neural fibers. These findings were consistent with neuromuscular and vascular hamartoma of the appendix.

Conclusion

This is the first report of neuromuscular and vascular hamartoma arising from the appendix.

Histopathologic Spectrum of Neuromuscular and Vascular Hamartoma With Special Reference to the Vasculopathic Phenomenon

Neuromuscular and vascular hamartoma (NMVH) is an unusual lesion presenting as intestinal obstruction by stricture formation. It is characterized by a hamartomatous mass comprising haphazardly arranged mesenchymal tissue native to the intestinal mucosa and submucosa. We aimed to characterize the clinicohistopathological spectrum of NMVH in adult subjects with a search for an etiological clue. We reviewed 84 resected specimens (adult cases) of intestinal obstruction in our institute and diagnosed 4 cases with NMVH. A panel of special stains (Masson trichrome, Verhoeff-van-Gieson, and periodic acid–Schiff) and immunohistochemistry (smooth muscle actin, S100, Bcl2, CD34, vimentin, desmin, CD117, and CD3) were performed in all cases. All cases of NMVH showed characteristic hamartomatous mounds comprising haphazardly arranged smooth muscle, nerves, ganglia, vessels, and collagen with overlying mucosal ulceration. Adjacent bowel showed submucosal fibrosis, muscularis mucosae thickening, and duplication along with vasculopathy. A typical vasculopathy (“vessel-in-vessel” appearance) was seen in the submucosal and/or subserosal veins. Besides, different other forms of vasculopathic changes like obliterative venopathy and concentric myohypertrophy were also seen. One case had vasculitis and the patient died despite successful surgery. One other case was associated with lymphocytic ganglioneuronitis and granulomatous etiology. We conclude that NMVH can be multifactorial in origin although ischemia resulting from vasculopathy appears to be directly causative. The characteristic vasculopathy in the submucosal location may aid in the diagnosis of NMVH in small biopsy samples.