Uterine leiomyosarcoma (ULMS) is a rare condition, characterized by an aggressive behavior, with high rates of local recurrence and metastasis, leading to an early death.1–3 The time interval to the detection of metastasis is typically short, although there are some reports of long periods, a fact that may complicate diagnosis.4 We report an unusual case of a hysterectomized patient, who, as the result of a LMS, 26 years later presented lung metastasis.

A 77-year-old woman, who had undergone hysterectomy for uterine myoma 26 years ago, was admitted to our institution for an abnormal shadow of greater density in the lower left lobe (LLL) on chest X-ray. Contrast-enhanced thoracic computed tomography showed an opacity with 6.7cm in greatest dimension in the LLL, with relatively well-defined limits (Fig. 1a). No other distant metastasis or local recurrence was found. The mass was subsequently removed by lower left lobectomy (Fig. 1b). Histopathological examination revealed smooth muscle cells with nuclear atypia and mitotic activity compatible with high-grade pleomorphic LMS (Fig. 2a). When the patient's history of hysterectomy for myoma was taken into account, the hypothesis of a lung metastasis of ULMS was considered during the diagnosis. Fortunately, it was possible to review the slides of the uterine tumor resected (Fig. 2b). It all led to the conclusion that the morphologies were similar and the uterine neoplasm was considered a high-grade LMS. Thus, based on the past medical history and histologic similarity, she was diagnosed with ULMS metastasis. The patient was hospitalized for respiratory infection and disease progression, with a worsening of the performance status, so she did not start chemotherapy, as planned. She died 3 months later.

Figure 1.

(a) Chest X-ray, contrast-enhanced thoracic computed tomography. (b) Macroscopic appearance.

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Figure 2.

(a) Densely cellular tumor; cellular pleomorphism; by immunocytochemistry, the neoplastic cells express smooth muscle differentiation markers (α-actin). (b) Uterine tumor with pleomorphic nuclei with variable and bizarre size and shape. Some spindle smooth cells (upper left) and necrosis signs (center).

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The usual appearance of a lung metastasis is characterized by a large number of nodules, but the unilateral location of a mass does not rule out metastatic disease, as in this case. Lung metastasis often emerges soon after or even before the primary tumor is diagnosed. Nevertheless, metastasis may develop after a long tumor-free interval. The disease-free interval for the present case was 26 years, which was, to the best of our knowledge, the longest reported so far. Dios et al. have described a case of 21 years disease-free interval.5 Therefore, the chronicity of the disease must not lead us to ignore past clinical history, such as hysterectomy. The reason why these tumors have such a long free-disease interval remains uncertain and should be investigated. As suggested by this report, a long-term follow-up is necessary in the case of ULMS. A high level of suspicion of lung metastasis is essential when a pulmonary lesion is detected, despite the fact that such situations are so rare.