Hereditary internal anal sphincter myopathy: the first Caribbean family

Hereditary proctalgia is an extremely rare condition characterized by endosonographic evidence of internal anal sphincter (IAS) thickening and specific ultrastructural changes seen at light and electron microscopy (EM). We report the case of a 54-year-old Caribbean woman with severe proctalgia and IAS thickening, treated with IAS myectomy. Transmission EM showed PAS-positive inclusions and granulofibrillary smooth muscle inclusion bodies. Anal endosonography of 5 family members from 3 generations showed IAS thickening in all cases with reported proctalgia. The condition represents an isolated IAS myopathy which is a probable polysaccharide storage disease variant. This condition may require specific surgical therapy with specimen preservation and ultrastructural examination for optimal characterization and treatment.