Date Published: April 7, 2017
Publisher: Springer US
Author(s): Go Nakai, Takashi Yamada, Takamitsu Hamada, Natsuko Atsukawa, Yoshikazu Tanaka, Kiyohito Yamamoto, Akira Higashiyama, Hiroshi Juri, Atsushi Nakamoto, Kazuhiro Yamamoto, Yoshinobu Hirose, Masahide Ohmichi, Yoshifumi Narumi.
Venous infarction of a leiomyoma is known as red degeneration of leiomyoma (RDL) and can be a cause of acute abdomen. Although magnetic resonance imaging (MRI) is the only modality that can depict the inner condition of a leiomyoma, the typical MR findings of RDL are sometimes identified incidentally even in asymptomatic patients. The purpose of this study is to clarify common pathological findings of uterine tumors preoperatively diagnosed as RDL by MRI.
We diagnosed 28 cases of RDL by MRI from March 2007 to April 2015. The ten lesions subjected to pathological analysis after resection were included in the study and reviewed by a gynecological pathologist. The average time from MRI to operation was 4.7 months.
The typical beefy-red color was not observed on the cut surface of the tumor except in one tumor resected during the acute phase. All lesions diagnosed as RDL by MRI had common pathological findings consistent with red degeneration of leiomyoma, including coagulative necrosis. Other common pathological features of RDL besides extensive coagulative necrosis appear to be a lack of inflammatory cell infiltrate or hemorrhage in the entire lesion.
Although RDL is known to cause acute abdomen, its typical MR findings can be observed even in asymptomatic patients in a condition that manifests long after red degeneration. The characteristic pathological findings in both the acute phase and the chronic phase that we found in this study, along with radiology reports, will be helpful references for gynecologists and pathologists in suspecting a history of red degeneration and confirming the diagnosis.
In our hospital, 28 cases of RDL were diagnosed by MRI from March 2007 to April 2015. These cases were retrieved from the radiology report database using the keyword “red degeneration of leiomyoma.” Common MRI findings were as follows. All uterine lesions were well demarcated and had a hyperintense rim or were entirely hyperintense compared to uterine myometrium on T1-weighted imaging (WI). On T2WI, the lesions had a distinct hypointense rim or were entirely hypointense compared to uterine myometrium. In three cases (cases 1, 5, and 9) in which gadolinium-enhanced fat-suppressed T1WI was performed, the tumors did not show any contrast enhancement. These findings are known among radiologists as the MR appearance of red degeneration of uterine leiomyoma . A radiologist (G.N.) with 12 years of experience in gynecological imaging confirmed that all lesions met the criteria. MR findings in each patient are summarized in Table 1.Table 1MR findings in each patientCaseAgeT1WIT2WIDWIGadolinium-enhanced fat-suppressed T1WI141Hypointense with hyperintense rimHeterogeneous hypointense with distinct hypointense rimIsointense with thin, distinct hypointense peripheral rimComplete absence of tumor contrast enhancement244Slightly hyperintenseHyperintenseHypointenseN/A335Inhomogeneous hyperintenseHeterogeneous hypointense with a distinct hypointense rimHyperintenseN/A434HyperintenseHyperintense with a thick hypointense rimHeterogeneous hyperintenseN/A545Hypointense with hyperintense rimHypointenseHypointenseComplete absence of tumor contrast enhancement639HyperintenseHyperintense with distinct hypointense rimN/AN/A747Mildly hyperintenseHeterogeneous hypointense with distinct hypointense rimHeterogeneous hyperintense with distinct hypointense rimN/A831Hypointensewith hyperintense rimHypointenseN/AN/A934Mildly hyperintenseHyperintense with distinct hypointense rimHyperintense with distinct hypointense rimComplete absence of tumor contrast enhancement1033Slightly hyperintense with distinct hyperintense rimHypointense with distinct hypointense rimN/AN/ASignal intensity (SI) shown is SI relative to SI of uterine myometriumN/A not available
Clinical courses of patients are summarized in Table 2. The mean patient age was 38 years (range 31–47). The average time from MRI to operation was 4.7 months (range 1.2–16) and 3 patients (cases 2, 3 and 10) were treated with gonadotrophin-releasing hormone agonists before surgery. Past symptoms suggestive of red degeneration were mentioned in clinical records of 6 patients (cases 1, 3, 4, 8, 9 and 10), all of whom experienced low abdominal pain with or without fever and were treated with a pain reliever and antibiotics in accordance with a clinical diagnosis of endometritis or myometritis made without using MRI. The suspected risk factor for onset was postpartum status for two patients (cases 4 and 8), post-abortion status for one patient (case 3) and pregnancy for two patients (cases 9 and 10). One patient (case 1) did not have any risk factors. Symptoms suggestive of red degeneration were not found in past clinical records of any other patients. Four patients underwent hysterectomy, five patients underwent laparoscopic myomectomy using a power morcellator (cases 3, 4, 6, 8, and 10), and one patient underwent abdominal myomectomy. A power morcellator was used before the U.S. Food and Drug Administration recommended strict limits on use of the tool for fibroid surgery in 2014. Radiological and pathological characteristics of the lesions are summarized in Table 3. Four patients had multiple myomas, but only one myoma was diagnosed as red degeneration on MRI in each patient (cases 2, 4, 5, and 7). On MRI, all lesions were well demarcated and ranged in size from 4.3 to 10.8 cm in largest diameter with a mean of 7.6 cm. The location of the affected leiomyoma was intramural in eight patients and submucosal in two patients.Table 2Clinical courses of patientsCaseAgeSymptom suggestive of RLSuspected risk factor for the onsetTreatment before surgeryThe perioda between the onset and operation (M)The perioda between the last MRI and surgery (M)The reason for the operationSurgery141LAP, feverUnclear6 month course of GnRHa1.41.2Intractable feverATH244UnclearUnclear3 month course of GnRHaN/A2Abnormal genital bleedingTLH335LAP, feverPost-abortionNone64.8Abortion coused by leiomyoma supposedlyLM using a PM434LAPPostpartumNone4.22.1Dysuria, LAP and an ovarian tumorLM using a PM545UnclearUnclearNoneN/A15.8Pollakiuria, low abdominal protuberanceATH639UnclearUnclearNone>362DysmenorrheaLM using a PM747UnclearUnclearNoneN/A3.8Hypermenorrhea, abnormal genital bleedingATH831LAPPostpartumNone2.31.9Abnormal genital bleedingLM using a PM934LAPDuring pregnancyNone19.55.7Large uterin tumor and an ovarian tumorAbdominal myomectomy1033LAPDuring pregnancy5 month course of GnRHa>348Large uterin tumorLM using a PMaPeriod is in months (M)LAP low abdominal pain, RDL red degeneration of leiomyoma, ATH abdominal total hysterectomy, TLH total laparoscopic hysterectomy, LM laparoscopic myomectomy, PM power morcellatorTable 3Radiological and pathological characteristics of lesionsCaseThe location of the affected myomaThe number of the affected myomaThe total number of myomaThe maximum diameters of the affected myomaPostoperative pathological reportGross appearanceCoexisting disease1Intramural11108Degenerative leiomyomaBeefy-red appearanceNone2Intramural1543LeiomyomaHomogeneous pink-tan appearanceNone3Intramural1170Hyaline degeneration of leiomyomaHomogeneous pink-tan appearanceNone4Intramural1276LeiomyomaHomogeneous pink-tan appearanceMature cystic teratoma of the right ovary5Intramural1More than 2071LeiomyomaN/ANone6Intramural1154Hyaline degeneration of leiomyoma or coaculative necrotic tissueHomogeneous pink-tan appearanceNone7Intramural1280Hyaline degeneration of leiomyomaHomogeneous pink-tan appearanceNone8Submucosal1162Necrotic tissueHomogeneous pink-tan appearanceNone9Submucosal11101Hyaline degeneration of leiomyomaHomogeneous yellow-tan appearanceEndometriotic cyst of the left ovary10Intramural1197Degenerative leiomyomaHomogeneous pink-tan appearanceNoneThe location, number, and maximum diameter of lesions was assessed by MRI
The MR appearance of acute-phase red degeneration of uterine leiomyoma was described in a study in which all five cases were associated with abortion or pregnancy . In this study, five of six patients who had symptoms suggestive of red degeneration had those risk factors, but the remaining patient did not have any risk factors (case 1).