An Intriguing Subcutaneous Nodule on Right Upper Arm

CASE REPORT A 49-year-old female noticed a deep-seated nodule with rubbery consistency on right upper arm for 2 months. Erythematous change on surface was seen (Fig. 1). She was suffered from mild itching sensation without pain or tenderness. The lesion progressed in size gradually. She visited our hospital for help and excisional biopsy was performed. Histologically, a well-defi ned nodule circumscribed by eosinophilic cuticle was found in subcutaneous tissue. The wall of nodule consisted of three layers, including eosinophilic integument, smooth muscle fi bers, and columnar tegumental cells. Numerous basophilic calcareous bodies, excretory ducts, and smooth muscle bundles were noted in loose stroma of parenchyma (Fig. 2). Besides, bothrium, a suction groove, was discovered in the cephalic direction after serial sections (Fig. 3). There was no protoscolex, suckers, or hooklets. A dense infl ammatory cell infi ltrate, containing lymphohistiocytes, eosinophils, plasma cells and multinucleate giant cells, was present around the nodule. The laboratory tests revealed no leukocytosis or eosinophilia. Resident Forum