Abstract
In 1995 Acta Radiologica published an article written by Wang Wu and Karl-Åke Thuomas with the title “Pituitary microadenoma. MR appearance and correlation with CT” (1). Later on, some doubts were raised concerning the validity of the original material as non-radiologists while re-examining the material found “some disagreements in the material”. This question was further complicated as the first author (Wang Wu) left Sweden and moved to Beijing. Due to these unclear circumstances the article was retracted in 1999 (2). During a journey to Beijing back in 2010, Dr Thuomas obtained access to the material of Wang Wu with a complete list of patients included in the material.
According to the article, magnetic resonance imaging (MRI) and computed tomography (CT) were performed on 113 consecutive patients referred to Linköping University Hospital with clinically and endocrinologically suspected pituitary adenomas in the period 1990–1994. Inclusion criteria were: (i) the focal pituitary lesion was not larger than 10 mm in maximum diameter; (ii) the final diagnosis was verified after transsphenoidal operation; and (iii) MRI and CT investigations were performed within 1 week. Twenty pituitary adenomas (15 women and 5 men) met these criteria and were included in the study; the remaining 93 patients had surgically verified macroadenomas according to the original article (1). Table 2 in the original publication gives a survey of the 20 patients presenting the focal lesion size and some secondary findings.
The list of patients obtained from Dr Wu included 28 patients, this in discrepancy to the original publication which included 20 patients only. The explanation of this discrepancy was, according to the authors, that eight of the patients on the original list did not have both MRI and CT examinations.
Since the list with 28 patients was sent to the Chief Editor in this period (Professor Emeritus Anders Hemmingsson), some investigations have been carried out in order to disclose the reliability of the patient list obtained from the first author of the original article. This work was complicated by the present situation of the old archives at the Department of Radiology at Linköping University in the period 1990–1994 due to the digitalization of the old archives.
This examination did confirm the information given in the original article concerning 12 of the 28 patients on the list of Dr Wu. Seven of these patients had an MRI of the sella during the period 1990–1994 with a radiological as well as a clinical diagnosis of a pituitary microadenoma. One case (no. 8) had an inconclusive examination as the patient was not willing to undergo a contrast examination; furthermore, this examination was performed at another hospital. In two cases it could be confirmed that a MR examination was undertaken at another hospital with a radiological diagnosis of a pituitary adenoma. In one of these cases the clinical history refer to a MR examination carried out at the Department of Radiology at the University Hospital in Linköping, however, this information could not be confirmed probably due to the deficits of the old archives at the University Hospital. In two cases it could not be documented that MR examinations had been carried out, however, the old files revealed that at least a CT examination had been undertaken, with a diagnosis of a pituitary adenoma. Only two of these 12 patients were referred from the Neurosurgical Department, the other patients were referred from other clinical departments in the area.
For 13 of the remaining patients it could be confirmed that an examination was undertaken in the period 1990–1994, but it has not been possible to reveal the nature of the radiological examination and the results.
To sum up, it is a possible explanation that the missing information is due to the condition of the old archives during and after the digitalization process. It cannot be confirmed that all information given in the original article (1) is correct, however, we have not found any proof to confirm that the patient material was fabricated. We therefore have to conclude that even if reliable conclusions cannot be drawn after almost 20 years, no proofs indicating a fabricated, non-reliable patient material have been found by the present investigation.