Extracardial rhabdomyoma:a clinicopathologic analysis of 9 cases
10.3760/cma.j.issn.0529-5807.2014.11.009
- VernacularTitle:心脏外横纹肌瘤的临床病理学观察
- Author:
Qiuyan SUN
1
;
Weng I LAO
;
Lin YU
;
Jiang LI
;
Jian WANG
Author Information
1. 212001,江苏省镇江市第一人民医院病理科
- Keywords:
Soft tissue neoplasms;
Rhabdomyoma;
Immunohistochemistry;
Diagnosis,differential
- From:
Chinese Journal of Pathology
2014;(11):757-762
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the clinicopathologic characteristics , differential diagnosis and biological behavior of extracardiac rhabdomyoma.Methods Nine cases of extracardiac rhabdomyoma diagnosed between January of 1997 and July of 2014 were reviewed.The clinical , pathologic and immunohistochemical profiles were evaluated.Results There were 5 males and 4 females at diagnosis with age ranging from 2 years and three months to 59 years (mean, 37.6 years).Sites included the head and neck region (7 cases), chest (1 case ) and vagina wall (1 case).Clinically, most cases manifested as a subcutaneous nodule or as a submucosal polypoid lesion with a mean diameter of 3.2 cm.Histologically , 4 were adult-type rhabdomyoma characterized by tightly packed large round or polygonal rhabdomyoblasts with abundant eosinophilic to clear cytoplasm; 3 were myxoid variant of fetal rhabdomyoma composed of immature myofibrils, spindled and primitive mesenchymal cells embedded in a myxoid background , 1 was an intermediate form of fetal rhabdomyoma consisting of densely arranged differentiated myoblasts with little myxoid stroma;1 was a genital rhabdomyoma composed of elongated or strap-like myoblasts scattered in loose fibrous connective tissue.By immunohistochemistry , they showed diffuse and strong positivity for desmin , MSA and myoglobin with variable expression of myogenin.A case of intermediate type also stained forα-smooth muscle actin.Follow up data ( 2 months ~17 years ) showed local recurrence in one patient 6 months after surgery.Conclusions Rhabdomyoma is a distinctively rare benign mesenchymal tumor showing skeletal muscle differentiation , which may occassionally recur if incompletely excised.Familiarity with its clinical and morphological variants is essential to avoid misdiagnosing this benign lesion as embryonal rhabdomyosarcoma.
