Apparent spontaneous regression of malignant neoplasms after radiography: Report of four cases.
BACKGROUND
On rare occasions, an apparently spontaneous regression of unknown etiology is observed in a neoplasm. We report a series of 4 patients with apparent spontaneous regression of malignant lymphomas after radiography.


METHODS
All four of the tumors were malignant lymphomas. The regressions occurred between 1 and 2 months after the radiographic examinations. All four patients later underwent relapse and needed additional treatments: surgery, chemotherapy and/or radiation.


CONCLUSIONS
Four cases had the following features in common: (1) the neoplasms were radiosensitive, (2) the regression occurred after radiography, (3) none of the neoplasms was in the advanced stage, and (4) the doses received through radiographic exposure were a little higher than usual because CT was included for most of the patients.


CONCLUSIONS
We suspect that the apparently spontaneous regression of malignant lymphomas was caused by the small radiation doses received in the radiographic examinations.
Kurihara Thyroid Clinic, Iwate, Japan. Electronic address: junshuku@zoo.email.ne.jp.
Jun
J
Sasaki
Kurihara Thyroid Clinic, Iwate, Japan. Electronic address: kclinic@rnac.ne.jp.
Hideo
H
Kurihara
Kurihara Thyroid Clinic, Iwate, Japan. Electronic address: sakira@iwate-med.ac.jp.
Yoshishige
Y
Nakano
Kurihara Thyroid Clinic, Iwate, Japan. Electronic address: sakirasimu@gmail.com.
Kohji
K
Kotani
First Komaki Hospital, Aichi, Japan. Electronic address: komaki-hosp@med-junseikai.or.jp.
Eisuke
E
Tame
Department of Surgery, Iwate Medical University School of Medicine, Iwate, Japan. Electronic address: sakira.iwate.med.u@gmail.com.
Akira
A
Sasaki
Cancer; Case report; Malignant lymphoma; Radiography; Spontaneous regression