Prompted by a unique case of an ectomesenchymal chondromyxoid tumor (ECT) of the palate in a 54-year-old female, we reviewed the English and German literature on this entity until the end of 2016 using PubMed. The search produced 74 lingual cases with a nearly equal sex distribution and a mean age of 39.3 years, and two extra-lingual cases sharing histological and immunohistological features including nodular growth, round, fusiform or spindle-shaped cellular architecture, and chondromyxoid stroma. Immunophenotyping showed the majority of cases to be positive for glial fibrillary acidic protein (GFAP), S-100 protein, glycoprotein CD57, pancytokeratin (AE1/AE3), and smooth muscle actin (SMA); in isolated cases there was molecular-genetic rearrangement or gain of Ewing sarcoma breakpoint region 1 (EWSR1) but no rearrangement of pleomorphic adenoma gene 1 (PLAG1). At present, ectomesenchymal cells that migrate from the neural crest are considered to play a pivotal role in tumor origin. All cases had a benign course, although there were three recurrences. Because of the rarity of this tumor and the need for differential diagnostic differentiation from myoepithelioma and pleomorphic adenoma, both oral surgeons and pathologists should be aware of this entity.
Biomarkers, Tumor ; analysis ; Chondroma ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Immunophenotyping ; Mesenchymoma ; pathology ; surgery ; Middle Aged ; Myoepithelioma ; pathology ; surgery ; Palatal Neoplasms ; pathology ; surgery

OBJECTIVETo investigate the clinicopathologic characteristics, differential diagnosis and biological behavior of extracardiac rhabdomyoma.

METHODSNine cases of extracardiac rhabdomyoma diagnosed between January of 1997 and July of 2014 were reviewed. The clinical, pathologic and immunohistochemical profiles were evaluated.

RESULTSThere 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 for α-smooth muscle actin. Follow up data (2 months ~ 17 years) showed local recurrence in one patient 6 months after surgery.

CONCLUSIONSRhabdomyoma 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.

Adolescent ; Adult ; Cell Differentiation ; Child ; Child, Preschool ; Desmin ; analysis ; Diagnosis, Differential ; Female ; Head and Neck Neoplasms ; chemistry ; pathology ; Humans ; Immunohistochemistry ; Male ; Mesenchymoma ; pathology ; Middle Aged ; Myogenin ; analysis ; Neoplasm Recurrence, Local ; Rhabdomyoma ; chemistry ; pathology ; Rhabdomyosarcoma, Embryonal ; pathology ; Thoracic Neoplasms ; chemistry ; pathology ; Thoracic Wall ; pathology ; Vaginal Neoplasms ; chemistry ; pathology

Cell Differentiation ; Child ; Dermatofibrosarcoma ; metabolism ; pathology ; Diagnosis, Differential ; Humans ; Immunohistochemistry ; Infant ; Lipoblastoma ; metabolism ; pathology ; Liver Neoplasms ; metabolism ; pathology ; Mesenchymoma ; metabolism ; pathology ; Neoplasms, Germ Cell and Embryonal ; metabolism ; pathology ; Sarcoma ; metabolism ; pathology ; Skin Neoplasms ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology

Actins ; metabolism ; Bone Neoplasms ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Hypophosphatemia ; blood ; etiology ; Ilium ; Mesenchymoma ; blood ; complications ; diagnostic imaging ; pathology ; surgery ; Middle Aged ; Osteomalacia ; blood ; etiology ; Phosphates ; blood ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Tomography, X-Ray Computed

Antigens, CD34 ; metabolism ; Choriocarcinoma ; pathology ; Diagnosis, Differential ; Female ; Hemangioma ; metabolism ; pathology ; Humans ; Keratin-18 ; metabolism ; Mesenchymoma ; pathology ; Placenta ; pathology ; Placenta Diseases ; metabolism ; pathology ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Pregnancy ; Pregnancy Complications, Neoplastic ; metabolism ; pathology ; Young Adult

12E7 Antigen ; Aged ; Antigens, CD ; metabolism ; Cell Adhesion Molecules ; metabolism ; Diagnosis, Differential ; Giant Cell Tumors ; pathology ; Giant Cells ; pathology ; Humans ; Male ; Mesenchymoma ; pathology ; Mucin-1 ; metabolism ; Myositis Ossificans ; pathology ; Osteosarcoma ; metabolism ; pathology ; surgery ; Penile Neoplasms ; metabolism ; pathology ; surgery ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Vimentin ; metabolism

Desmin ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Infant ; Ki-67 Antigen ; metabolism ; Mesenchymoma ; drug therapy ; metabolism ; pathology ; surgery ; Nerve Sheath Neoplasms ; metabolism ; pathology ; Phosphopyruvate Hydratase ; metabolism ; Rhabdomyosarcoma, Embryonal ; drug therapy ; metabolism ; pathology ; surgery ; Teratoma ; metabolism ; pathology ; Vulvar Neoplasms ; drug therapy ; metabolism ; pathology ; surgery

A chondrolipoma is an extremely rare form of a benign mesenchymal tumor containing mature cartilage and fatty tissue. Chondrolipomas may be found in almost any part of the body, particularly in the connective tissue of the breast, head and neck area, as well as in the skeletal muscle. However, to the best of our knowledge, chondrolipomas located in the pelvic cavity have not been reported. In this case report, we describe a case of a chondrolipoma in the pelvis, and show that it has its own characteristic imaging findings, which included the composition of fatty tissue and calcification in most parts, as well as some focal areas of chondroid tissue based on the CT and MR findings.
Chondroma/*diagnosis ; Humans ; Lipoma/*diagnosis ; Male ; Mesenchymoma/*diagnosis ; Middle Aged ; Pelvic Neoplasms/*diagnosis ; Tomography, X-Ray Computed

Adult ; Aged ; Angiomyolipoma ; diagnosis ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnosis ; diagnostic imaging ; Diagnosis, Differential ; Female ; Fibroma ; diagnosis ; diagnostic imaging ; Humans ; Kidney Neoplasms ; diagnosis ; diagnostic imaging ; Leiomyosarcoma ; diagnosis ; diagnostic imaging ; Male ; Mesenchymoma ; diagnosis ; diagnostic imaging ; Middle Aged ; Tomography, Spiral Computed ; methods

Actins ; metabolism ; Adult ; Antigens, Neoplasm ; metabolism ; Diagnosis, Differential ; Epithelioid Cells ; chemistry ; pathology ; Female ; Humans ; Hysterectomy ; Immunohistochemistry ; Melanoma-Specific Antigens ; Mesenchymoma ; metabolism ; pathology ; surgery ; Neoplasm Proteins ; metabolism ; Uterine Neoplasms ; metabolism ; pathology ; surgery