An unusual case of an osteosarcoma arising in a leiomyoma of the uterus

Multidisciplinary management for primary uterine osteosarcoma, including gene panel testing: case report and literature review

Primary osteosarcoma of the uterus (uOS) is rare, and its standard treatment has not yet been established. Herein, we present the case of a 50-year-old woman with uOS who demonstrated an improved prognosis after multiple surgeries to the metastatic sites. After the initial diagnosis of uOS, the patient showed recurrence and distant metastasis and hence expected to exhibit a poor prognosis. The patient underwent multiple surgical resections of the metastatic as well as primary tumors, which enabled the patient to survive for 24 months after the initial surgery. Considering that the median survival time of patients with uOS is approximately 6 months, the survival rate of our patient is noteworthy. Based on our observations, it is suggested that the resection of the primary and metastatic tumors might contribute to the extension of the survival period of the patient with chemo-resistant uOS.

"Malignant Mesenchymoma" Revisited: A Clinicopathologic Study of Leiomyosarcomas With Osteosarcomatous Differentiation

Leiomyosarcoma (LMS) is the most common sarcoma in adults. Rarely, LMS dedifferentiates into an undifferentiated sarcoma. Very few cases of LMS with heterologous osteosarcomatous differentiation (OS) have been reported. The purpose of this study was to evaluate the clinicopathologic features of LMS with OS. Of 5570 LMS cases diagnosed from 2006 to 2022, 15 cases (0.2%) of LMS with OS were identified, affecting 13 females and 2 males; ages ranged from 32 to 66 years (median: 53 y). Ten tumors arose in the uterus, 2 in the retroperitoneum, and 1 each in the mesentery, mediastinum, and rectum. Primary tumors ranged from 7 to 20 cm (mean: 16 cm). The LMS components showed conventional spindle cell morphology in most cases; 3 cases showed marked pleomorphism; 3 cases contained an epithelioid component; and 1 case showed myxoid features. In 5 cases OS was identified in the primary tumor, whereas in 10 cases OS was first detected in metastases. One metastatic and 2 primary LMS showed both OS and chondrosarcomatous differentiation. Prominent osteoclastic giant cells were seen in the OS components in 11 cases. Mitotic activity ranged from 17 to 61/10 HPF with tumor necrosis in 10 cases. Twelve patients developed metastases; sites included lungs, diaphragm, kidney, adrenal glands, colon, small intestine, liver, bone, and pancreas. At last follow-up, 8 patients had died of disease, and 4 patients were alive with metastases. The interval between OS and death ranged from 3 weeks to 18 months (median: 6.5 mo). Development of OS in LMS is exceptionally rare. This form of heterologous differentiation may occur in both primary tumors and metastases. LMS with OS is highly aggressive with poor outcomes. Awareness of this phenomenon is important to avoid misdiagnosis as osteosarcoma.

Epithelioid leiomyoma of the uterus: A case report with magnetic resonance imaging findings

Epithelioid leiomyoma of the uterus is rare, and its prognostic factors have not been well established. Moreover, radiologic findings of this disease have not been previously documented. This is a case of a 49-year-old woman with epithelioid leiomyoma of the uterus. Magnetic resonance imaging (MRI) revealed a heterogeneous high-intensity mass with multiple ordinary uterine leiomyomas. The mass showed a slightly diffusion-restricted site. Since benign tumors could not be confidently diagnosed using these MRI findings, total abdominal hysterectomy with bilateral salpingectomy was performed, and a pathological diagnosis of epithelioid leiomyoma of the uterus was established. Microscopically, this lesion showed edematous changes and cyst formation, causing a heterogeneous appearance on T2-weighted images. In addition, the diffusion-restricted site is considered to be consistent with areas of solid and dense proliferation of tumor cells. The patient survived and was well 10 months after the surgery. It is important to recognize this benign variant of leiomyoma with an unusual appearance, to provide appropriate therapeutic management.

•

Epithelioid leiomyoma of the uterus is rare.

•

Radiologic findings of this disease have not been documented previously.

•

It is important to recognize this benign variant of leiomyoma with an unusual appearance.

High-grade uterine sarcoma with osteosarcomatous differentiation arising from a MED12-mutated leiomyoma, a case report

Uterine osteosarcoma has been reported, but it is an extremely rare tumor with highly aggressive behavior and poor prognosis. The pathogenesis of uterine osteosarcoma is not fully understood. Herein, we report on a high-grade uterine sarcoma with focal osteosarcomatous differentiation that developed from a long-standing MED12-mutated leiomyoma. A 47-year-old nulligravida woman, with known uterine leiomyoma presented with abdominal pain and distention. Imaging analyses revealed a tumor with a large cystic area in the uterine corpus and multiple metastases in intrapelvic and paraaortic lymph nodes, left ovary and left lung. With a clinical diagnosis of uterine sarcoma the patient underwent abdominal total hysterectomy, bilateral salpingo-oophorectomy, partial omentectomy and removal of the left obturator lymph node. Despite postoperative chemotherapy and radiation therapy, the tumor progressed rapidly. She died 18 weeks after the surgery. Histopathologic examination identified a high-grade pleomorphic sarcoma in which focal osteoid production was observed. This high-grade sarcoma with focal osteosarcomatous differentiation was located within the uterine leiomyoma, and Sanger sequencing showed the identical MED12 L36R mutation in both the osteosarcomatous and leiomyomatous components supporting the shared origin of these two components. We, therefore, concluded that the high-grade sarcoma with osteosarcomatous differentiation arose from the transformation of the precedent leiomyoma.

Immunofluorescence analysis of DNA damage response protein p53-binding protein 1 in a case of uterine dedifferentiated leiomyosarcoma arising from leiomyoma

AIMS

Genomic instability has been indicated during the dedifferentiation process from leiomyoma (LM) to leiomyosarcoma (LMS). Previously, we have described that nuclear expression pattern of DNA damage response protein p53-binding protein 1 (53BP1), detected by immunofluorescence, reflects the magnitude of genomic instability during malignancy. Here, we present a case of LMS arising from LM with molecular analysis of 53BP1, which showed transitional magnitude of DNA damage response within a tumor.

METHODS AND RESULTS

A fifty-year-old female with abdominal mass underwent hysterectomy. Histologically, the tumor consisted of LMS with highly atypical multinucleated giant cells as well as an LM component with transitional atypical spindle cells in the border area. LMS showed diffuse nuclear staining of 53BP1 expression, which has been previously described as high DNA damage response pattern. In contrast, the LM component lacked 53BP1 immunoreactivity and focal expression was observed in transitional lesion. Furthermore, double-labelled immunofluorescence revealed co-localization of 53BP1 with p53 and Ki-67 in the LMS component, which indicated abnormal DNA damage response in proliferative state.

CONCLUSIONS

This study revealed that diffuse-type 53BP1 expression may be beneficial to estimate genomic instability during dedifferentiation from LM to DLMS.

Primary osteosarcoma of the uterine corpus: A case report

Pure osteosarcoma arising from the uterus is extremely rare. Only 15 cases of this type of cancer have been reported to date. Most patients showed local or lung metastasis early after surgery and died within a year of treatment initiation, regardless of multimodality therapy, indicating that this tumor is aggressive with a poor prognosis. Herein, we report the first clinical experience treated with a combination of docetaxel and gemcitabine for local and lung metastasis from primary osteosarcoma of the uterus. Although the disease was considered stable after three cycles of treatment, new metastatic lesions appeared in the lungs after six cycles. The patient was asymptomatic for 13 months; however, she died two months after symptom recurrence. Our case demonstrates that a combined regimen of docetaxel and gemcitabine may be a sound therapeutic option to control primary osteosarcoma of the uterus.

Molecular Analysis of a Recurrent Sarcoma Identifies a Mutation in FAF1

A patient presented with a recurrent sarcoma (diagnosed as leiomyosarcoma) 12 years after the removal of an initial cancer (diagnosed as extracompartmental osteosarcoma) distally on the same limb. Following surgery, the sarcoma and unaffected muscle and bone were subjected to measurements of DNA exome sequence, RNA and protein expression, and transcription factor binding. The investigation provided corroboration of the diagnosis leiomyosarcoma, as the major upregulations in this tumor comprise muscle-specific gene products and calcium-regulating molecules (calcium is an important second messenger in smooth muscle cells). A likely culprit for the disease is the point mutation S181G in FAF1, which may cause a loss of apoptotic function consecutive to transforming DNA damage. The RNA levels of genes for drug transport and metabolism were extensively skewed in the tumor tissue as compared to muscle and bone. The results suggest that the tumor represents a recurrence of a dormant metastasis from an originally misdiagnosed neoplasm. A loss of FAF1 function could cause constitutive WNT pathway activity (consistent with the downstream inductions of IGF2BP1 and E2F1 in this cancer). While the study has informed on drug transport and drug metabolism pharmacogenetics, it has fallen short of identifying a suitable target for molecular therapy.