Malignant mesenchymoma of the uterus, arising in a leiomyoma

A case report of recurrent leiomyosarcoma with chondrosarcoma differentiation in the abdominal wall and a review of the literature

Leiomyosarcoma with heterologous differentiation is relatively rare. To date, only 19 cases have been reported in the English literature. Heterologous components frequently show histological pleomorphism, while those exhibiting well-differentiated morphology are seldom reported. Here, we report a 34-year-old female diagnosed with leiomyosarcoma and developed abdominal wall recurrence 8 years after primary surgery. The recurrent tumor mainly comprised well-differentiated chondrosarcoma except a single focus of leiomyosarcoma. Due to the rarity and prolonged onset of such a transition, our case provides insight into the understanding of this phenomenon.

Metastatic Uterine Leiomyosarcoma With Rhabdomyosarcomatous Heterologous Differentiation

Heterologous differentiation has only been previously reported twice in metastatic uterine leiomyosarcomas. We report herein the first case of metastatic uterine leiomyosarcoma with rhabdomyosarcomatous differentiation. A 67-yr-old woman presented with femur, abductor magnus, and lymph node metastases 9 yr after the primary diagnosis. The metastatic sites showed rhabdomyosarcomatous morphologic features, and immunohistochemical studies confirmed skeletal muscle differentiation. Molecular testing revealed the same loss-of-function TP53 mutation in the uterine leiomyosarcoma and metastatic sites supporting heterologous differentiation of the primary tumor. Our case highlights the morphologic shifts metastatic tumors may manifest and the potential diagnostic problems that may arise.

"Unicorn in a Field of Horses": A Rare Case of Carcinosarcomatous Transformation in a Uterine Leiomyoma

Malignant transformation in leiomyoma is rare, with a few documented cases of sarcomatous transformation in leiomyomas. However, carcinosarcomatous transformation in leiomyomas is extremely infrequent. A 45-year-old female presented with a mass sensation per abdomen for the last five months. An abdominal ultrasound revealed multiple uterine fibroids. Contrast-enhanced magnetic resonance imaging revealed a large multiloculated abdominopelvic mass arising from the fundus of the uterus, along with multiple smaller subserosal fibroids. A total abdominal hysterectomy with bilateral salpingectomy was performed. Grossly, the uterus was bosselated with multiple subserosal fibroids. The larger degenerated fibroid showed a smooth outer surface; however, the cut surface was predominantly cystic and filled with necrotic material. Microscopically and immunohistochemically, the larger mass showed a high-grade biphasic tumor comprising carcinomatous and sarcomatous components with the peripheral solid areas showing compressed smooth muscle bundles representing the residual leiomyomatous areas. A final diagnosis of carcinosarcomatous transformation in leiomyoma was rendered. The index report highlights the significance of systematic gross and microscopic examination of all the uterine masses in patients with multiple leiomyomata.

"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.

Dedifferentiated leiomyosarcoma of the uterus with heterologous elements: a potential diagnostic pitfall

Dedifferentiation is a phenomenon that is well characterized in a variety of tumors and is defined by the occurrence of a high-grade or undifferentiated tumor, typically unrecognizable regarding its line of differentiation, from a low-grade/borderline neoplasm. This phenomenon has previously been described in 2 uterine leiomyosarcomas, but both were devoid of heterologous elements. The authors describe herein a case of a dedifferentiated leiomyosarcoma of the uterus with osteoid heterologous elements, believed to be the first such reported case. The original tumor was a high-grade leiomyosarcoma with large low-grade and leiomyoma-like areas and whose constituent cells displayed intense nuclear immunoreactivity for both estrogen receptor (ER) and progesterone receptor (PR) in approximately 30% of cells. The tumor recurred six months after its resection as an undifferentiated sarcoma that was negative for smooth muscle markers, but which remained positive for ER and PR. Osteoid production was only identified in the recurrent tumor and was significant in extent therein. This case highlights the immunophenotypic changes that may occur in dedifferentiated leiomyosarcomas, and this possibility should be a consideration when an apparently undifferentiated sarcoma is identified in a patient with a history of uterine leiomyosarcoma. In our case, the expression of ER and PR provided significant supportive evidence of the uterine origin of the recurrent tumor.

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

Leiomyoma is the most common uterine neoplasm. It has several histological variants such as atypical, cellular, myxoid, and epithelioid. Leiomyoma with heterologous elements is a rare variant of leiomyoma, which may contain heterologous elements such as fat, skeletal muscle, and chondroid and osseous tissues. The heterologous sarcomatous differentiation is also rarely seen. We report on a 53-year-old woman who was admitted with abnormal vaginal bleeding and symptoms related to an abdominal mass. She had a huge uterine leiomyoma that contained osteosarcomatous differentiation in several foci. Although malignant progression for leiomyoma is exceedingly rare, when it occurs it may result not only in a leiomyosarcoma but also in a heterologous sarcomatous differention. We have reported histopathological, immunohistochemical, and clinical features of this rare case and reviewed the published studies.

Metastatic leiomyosarcoma of the uterus with heterologous differentiation to malignant mesenchymoma

Heterologous differentiation in metastatic leiomyosarcomas of uterine origin is an extremely rare phenomenon. We report a remarkable case of a metastatic leiomyosarcoma from the uterus with an unusual pattern of tumor progression to malignant mesenchymoma after chemotherapy. The patient, an 80-yr-old woman with a history of metastatic leiomyosarcoma of the uterus to the lungs, presented with a large intra-abdominal mass. Histologic examination of the intraperitoneal mass demonstrated a high-grade sarcoma containing various heterologous malignant mesenchymal elements including osteosarcoma, chondrosarcoma, a liposarcoma-like area, and osteoclast-like multinucleated giant cells. Only the identification of small areas of smooth muscle differentiation revealed the true nature of the tumor as a metastatic leiomyosarcoma with aberrant sarcomatous differentiation. This unique presentation emphasizes the importance of clinicopathologic correlation in the diagnosis of tumors with unusual histology.

Carcinosarcoma arising in a uterine leiomyoma: report of a unique neoplasm

Malignant transformation of a uterine leiomyoma is an exceedingly rare phenomenon. Previous reported examples of malignant neoplasms to arise so include leiomyosarcoma, angiosarcoma, and malignant mesenchymoma. We report an intramural carcinosarcoma arising in a uterine leiomyoma in a 38-year-old woman. This case is unique in being the first recorded carcinosarcoma arising within a uterine leiomyoma and the first example of an epithelial neoplasm to do so. We discuss the differential diagnosis and possible pathogenesis of the tumor that has likely arisen secondary to epitheliogenesis in a mesenchymal neoplasm.

Heterologous and rare homologous sarcomas of the uterine corpus: a clinicopathologic review

Pure sarcomas of the uterine corpus are uncommon, constituting less than 3% of all malignancies at this site, and most of them are leiomyosarcomas and endometrial stromal sarcomas. Rare histotypes of homologous sarcomas and heterologous sarcomas are occasionally encountered, and the absence of significant accumulated experience with these histotypes at this location may potentially raise diagnostic and patient management difficulties. In this article, the clinicopathologic attributes of all earlier reported sarcomas of the uterine corpus other than leiomyosarcomas and endometrial stromal sarcomas are summarized. Included are embryonal rhabdomyosarcoma, pleomorphic rhabdomyosarcoma, angiosarcoma, alveolar soft part sarcoma, malignant perivascular epithelioid cell tumors (PEComas), osteosarcoma, chondrosarcoma, liposarcomatous tumors, malignant extrarenal rhabdoid tumors, Ewing sarcoma/primitive neuroectodermal tumor, and other rare histotypes. Embryonal rhabdomyosarcoma (20%), Ewing sarcoma/primitive neuroectodermal tumor (17%), angiosarcoma (14%), and pleomorphic rhabdomyosarcoma (13%) appeared to be more common than the others, although there was no single overwhelmingly prevalent histotype in the group. A subset, including embryonal rhabdomyosarcoma, alveolar soft part sarcoma, and PEComas, peak in the premenopausal years, but most of the others were observed in postmenopausal women. Favorable outcomes have been reported for the patients diagnosed with alveolar soft part sarcoma, and the prognosis for their counterparts with PEComa remains a matter of debate. Multimodal therapeutic approaches to contemporary patients with embryonal rhabdomyosarcomas have resulted in significantly improved outcomes. Unfortunately, most of the other sarcomas have been associated with rapid tumor progression and unfavorable patient outcomes. The differential diagnosis for these sarcomas is often extensive and varies by histotype, but their accurate diagnosis fundamentally requires the careful exclusion of biphasic malignancies.

Osteosarcoma Arising in a Long-Standing Uterine Leiomyoma: A Case Report and Literature Review

The authors present the first case of a pure osteosarcoma arising in a long-standing uterine leiomyoma along with a literature review of all heterologous sarcomas arising in uterine leiomyoma. Most cases present with abnormal vaginal bleeding and symptoms related to a rapidly enlarged pelvic mass in postmenopausal women with a long-standing history of uterine leiomyoma. The histological finding of the case in this study revealed a relatively well-circumscribed tumor with a peripheral ring of leiomyoma and a central osteosarcoma. The case in this study further supported a possible pathogenesis involving the p53 gene. The prognosis may be better with low-stage tumor; however, cases with advanced stages, larger tumor size at presentation, and histological type of epithelioid angiosarcoma had poorer prognosis despite aggressive therapy.

Malignant mesenchymoma arising from a uterine leiomyoma in the menopause

BACKGROUND

Malignant mesenchymoma is a rare tumor and location in the uterus is even rarer. We describe the first case of malignant mesenchymoma arising from a uterine fibroid in the menopause.

CASE REPORT

A 64-year-old woman presented with abdominal pain and underwent surgery for a large "uterine fibroid" with suspicious features on ultrasound scan. The mass had developed after the menopause. Histology showed benign leiomyomatous tissue with malignant areas consistent with malignant mesenchymoma.

CONCLUSION

We report the first case of malignant mesenchymoma arising from the uterus in menopause. Certain radiological features may be associated with this tumor. Due to its rarity, information on management of uterine malignant mesenchymoma is lacking and management options of uterine leiomyosarcomas are reviewed as a surrogate.

Pleomorphic liposarcoma of the uterus: case report and literature review

A 62-year-old woman with a history of breast carcinoma being treated with tamoxifen presented with a rapidly enlarging pelvic mass. Imaging studies suggested a uterine leiomyoma with possible sarcomatous transformation. Laparotomy revealed a 15-cm, oval, well-circumscribed mass emanating from the posterior cervix and left uterosacral ligament. The tumor had a variegated fleshy, tan, myxoid, and necrotic sectioned surface. Microscopic examination revealed a variety of patterns and cell types characteristic of liposarcoma that included myxoid/round cell, storiform/pleomorphic, epithelioid, and spindle cell areas. Lipogenic areas exhibited a "crow's feet" vasculature and characteristic lipoblasts. The tumor cells were highly pleomorphic with numerous mitotic figures, some of them atypical. The tumor cells were immunoreactive for vimentin, estrogen receptors, and S-100. The tumor recurred 9 months postoperatively. Although a variety of uterine tumors have been associated with tamoxifen treatment, this appears to be the first example of tamoxifen-associated uterine liposarcoma.