Atypical thymoma: a report of seven patients.
BACKGROUND
Most thymic neoplasms fall under the designation of thymoma, consisting of well-differentiated epithelial cells, resembling normal thymus. At the opposite spectrum are thymic carcinomas; the cell of origin while similar is malignant. Recently a third category of thymic neoplasms, atypical thymomas, has been recognized representing thymic neoplasms manifesting atypia although without overt cytomorphologic criteria of malignancy.


METHODS
Seven patients with a diagnosis of atypical thymoma were encountered over a 6-year period from the patient files of the cardiothoracic division of The Ohio State Medical Center.


RESULTS
In all patients there was gross or light microscopic invasive disease with involvement of the capsule, phrenic nerve, diaphragm, chest wall, and lung. Surgical extirpation/de-bulking along with radiation therapy in six and chemotherapy in one led to complete disease regression. Intrathoracic recurrences developed in 4 involving lung, pleura, chest wall and diaphragm. All patients are well.


CONCLUSIONS
Atypical thymomas are locally aggressive tumors with a high incidence of intrathoracic recurrence; extrathoracic spread is not seen. Our study corroborates other reports that death attributable to atypical thymoma is uncommon.
School of Medicine and Public Health, Ohio State University, Columbus, OH 43210, USA.
Johanna L
JL
Baran
Cynthia M
CM
Magro
Mark A
MA
King
Thomas E
TE
Williams
Patrick
P
Ross
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001808:Blood Vessels / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D003520:Cyclophosphamide / Q000008:administration & dosage; D003964:Diaphragm / Q000473:pathology; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D010496:Pericardium / Q000473:pathology; D010791:Phrenic Nerve / Q000473:pathology; D010994:Pleura / Q000473:pathology; D018714:Radiotherapy, Adjuvant; D012074:Remission Induction; D012189:Retrospective Studies; D035441:Thoracic Wall / Q000473:pathology; D013945:Thymoma / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D013953:Thymus Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D002945:Cisplatin