Lipomatous neometaplasia of the uterus. Report of 11 cases with discussion of histogenesis and pathogenesis

Uterine angiolipoleiomyoma. A case report and systematic literature review

Uterine angiolipoleiomyomas are rare, benign mixed mesenchymal lesions. A manifestation in the gynecological region is quite uncommon, with few cases described in the literature so far. We present an interesting case of a 59-year-old woman diagnosed with uterine angiolipoleiomyoma, and the results of the conducted systematic review of the literature. The patient presented with a pelvic mass masquerading as a leiomyoma on the ultrasound and postmenopausal vaginal bleeding. At laparotomy, a large uterus was noticed and the histopathology set the diagnosis of angiolipoleiomyoma. Immunohistochemistry revealed negativity for Melan-A and HMB-45 melanoma-specific antibodies and positivity for Van Gieson and orcein histochemical stains.

We systematically reviewed the literature. The eligible articles were those written in English, excluding animal studies and studies reporting angiolipoleiomyomas in other regions beside the uterus. The present case is one of the 10 cases of uterine angiolipoleiomyoma reported in the literature. In 8 out of 11 (72.7%) cases, uterine angiolipoleiomyomas arose from the corpus of the uterus, while in 2 (18.1%) cases they were located at the cervix, and in one case (9%) angiolipoleiomyoma was located in the broad ligament. Concerning symptoms, four of the patients (36.4%) presented with abdominal and pelvic pain, two (18.1%) with postmenopausal vaginal bleeding, one with menometrorrhagia (9%), and one with uterine prolapse and cystocele (9%). Immunohistochemical staining of uterine angiolipoleiomyomas was positive for SMA in 4 patients (36.4%), positive for desmin in 3 cases (27.3%), positive for anti-S-100 protein antibody in 2 patients (18.1%), while in one case (9%) immunopositivity was observed for CD31. Only our case (9%) was also tested for CD34, Van Gieson and orcein, the first of these being negative and the other two positive (at the blood vessels in a specialized pattern). Three of the patients (27.3%) were also tested for HMB-45 and all three were immunonegative.

In order to establish the diagnosis of uterine angiolipoleiomyomas, ultrasonography and additional MRI may help the preoperative prediction of a benign mass. Immunohistochemistry will show strong positivity of alpha-smooth muscle actin and desmin. Complete abdominal hysterectomy is the preferable treatment.

Pathogenesis, diagnosis and treatment of uterine lipoleiomyoma: A review

Uterine lipoleiomyomas are variants of uterine leiomyomas and are characterized by progressive enlargement that can occur even after menopause. These tumors can produce serious clinical symptoms and are difficult to diagnosis preoperatively. The growth rate of uterine lipoleiomyomas after menopause is comparatively higher than that of conventional uterine leiomyomas, and lipoleiomyosarcomas as well as tumor-to-tumor metastasis associated with lipoleiomyomas have been reported. However, detailed histogenic mechanisms of the tumor remain unclear. Surgical treatments are the current choice for the management of lipoleiomyomas. The purpose of this review is to promote greater awareness of lipoleiomyoma characteristics with a focus on histogenesis, diagnosis, and treatment. We performed an exhaustive literature review and have summarized the available data. We assessed the interpretation of auxiliary examinations to help physicians in making an early accurate diagnosis of the disease and to help with treatment decision-making, particularly regarding whether surgery should be performed or avoided.

Spindle Cell Sarcoma of the Uterine Corpus With Adipose Metaplasia: Expanding the Morphologic Spectrum of Neoplasms With MEIS1-NCOA2 Gene Fusion

We report a spindle cell sarcoma arising in the uterine corpus of a 26-yr-old patient. The patient underwent a simple hysterectomy and the uterine corpus contained a 9 cm tumor showing nodular and "finger-like" myometrial invasion. Histologically, the tumor was composed of a monomorphic population of atypical spindle cells which contained widespread foci of cytologically benign adipocytes. Immunohistochemistry revealed diffuse strong positivity for CD10, CD56, and CD99 and diffuse weak positive staining with ER and WT1 while smooth muscle markers, S100, TLE1, and cyclin D1 were negative. Total RNA sequencing identified an in-frame fusion between exon 6 of MEIS1 and exon 12 of NCOA2. Copy number analysis revealed few aberrations with no deletions or amplifications identified. No adjuvant therapy was given and the patient is disease-free 9 yr after initial diagnosis. This case represents the second report of a uterine sarcoma harboring a MEIS1-NCOA2/1 gene fusion and expands the morphologic spectrum of recently reported spindle cell sarcomas arising in the genitourinary tract harboring MEIS1-NCOA2/1 gene fusions. This is the first reported case of such tumors with an adipocytic component.

White Adipocytes of the Uterine Cervix Tend to Appear in Women of Older Age, Postmenopause Status, and Higher Body Mass Index

The human uterine cervix consists mainly of epithelium and stroma, including smooth muscle cells and fibrovascular tissues. Fat cells in the uterine cervix have been rarely reported, and the only previous research article has shown that intracervical adipocytes are unrelated to clinical factors. The aim of this study was to investigate the frequency of fat cells in the uterine cervix, as well as to evaluate the relationship between intracervical adipocytes and clinicopathologic factors. We retrospectively selected 405 cases in Japanese women who received cervical conization at our hospital between 2003 and 2017. Cervical conization was not performed during pregnancy or within 1 yr after childbirth. The prepared histologic specimens for pathologic diagnosis were available in all cases. Age, menopause status, body mass index, gravidity, and parity were selected clinical factors, which were obtained in 214 patients. The mean patient age was 42 yr (range, 22-80 yr). Intracervical white adipocytes were observed in 13% of patients (53/405), with no brown adipocytes detected. The existence of intracervical adipocytes was significantly correlated to older age (P<0.0001), postmenopause status (P<0.0001), and higher body mass index (P=0.0018). Intracervical adipocytes might undergo adipocytic metaplasia from cervical stromal cells in accordance with aging, postmenopause status, or weight gain. Our result also suggest that cervical malignancy involving fat cells does not necessarily imply parametrial invasion.

Uterine lipoleiomyoma

We report a case of a patient who was found to have a uterine lipoleiomyoma on ultrasound and MRI, which was later confirmed with histological evidence. Uterine lipoleiomyomas are rare benign tumours that are often misdiagnosed on imaging, leading to unnecessary invasive procedures. Increased awareness of the tumour and its characteristics on imaging can aid future preoperative diagnosis.

Clinical and pathological features of lipoleiomyoma of the uterine corpus: a review of 76 cases

BACKGROUND

Uterine lipoleiomyoma is a rare and specific type of leiomyoma with a considerable amount of adipocytes.

AIMS

The aim of the study was to investigate the clinical, pathological and immunohistochemical features of lipoleiomyoma of the uterine corpus, and review its histogenesis and differential diagnosis from other neoplastic and non-neoplastic lesions in order to obtain a detailed profile of this somewhat uncommon lesion.

STUDY DESIGN

Descriptive study.

METHODS

This study is a retrospective analysis of 70 consecutive women with 76 lipoleiomyomas, who underwent surgery mainly for uterine leiomyoma and gynecological carcinomas between January 2000 and April 2013. Clinical and pathological information was obtained from medical records. Immunohistochemistry was applied in selected cases. Parametric methods were used to compare clinical and pathologic features.

RESULTS

The patients ranged in age from 34 to 77 years (mean 55.49 years). Lipoleiomyomas ranged from 0.5 to 55 cm in diameter (mean 5.50 cm). Typical macroscopic and microscopic features were noted. Sixty-nine (90.7%) tumors were in the uterine corpus and five (6.5%) were in the cervix. One broad ligament tumor and one retroperitoneal tumor were also studied. No tumors displayed cytologic atypia, mitosis, necrosis, calcification, or other degenerative changes. Immunohistochemically, the adipose tissue element was positive for vimentin, desmin, S100 protein, estrogen (ER), progesterone (PR), and Ki-67. Among patients with lipoleiomyomas, 53 cases (75.7%) had different types of lesions associated with hyperestrogenic status, such as adenomyosis, endometriosis, endometrial hyperplasia, and polyps, complex atypical endometrial hyperplasia, and gynecologic carcinomas. The follow-up period ranged from one to eight years (mean 4.6 years). There were no recurrences or tumor-related fatalities.

CONCLUSION

In the present study, the lipoleiomyomas were seen more frequently in patients with adenomyosis, endometriosis, endometrial hyperplasia, polyps, and various gynecologic carcinomas. Lipoleiomyoma of the uterus seems to have a benign clinical course.

Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor

Abstract

Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643

Lipoma of the uterine corpus: exceptional eventuality combined with an ovarian thecoma

Uterine lipomas are very uncommon with symptoms that are similar to leiomyomas. Their diagnosis is always histological although some radiological methods may suggest their existence prior to surgery. They are sometimes associated with endometrial pathology, but there are no previous reported cases related to ovarian thecoma. Their prognosis is excellent. Clinical, radiological, morphologic, and immunohistochemical findings are shown which correspond to uterine lipoma associated with endometrial polyps and ovarian thecoma.

Uterine Lipoleiomyomas

Lipoleiomyoma is an uncommon uterine neoplasm and, although presumed to be benign, has been inadequately studied. Confirming the benign nature of this tumor is important because it can closely resemble well-differentiated liposarcoma. We evaluated 50 consecutive lipoleiomyomas diagnosed at the Washington Hospital Center from 1998 to 2004; 2.1% of patients who had uterine leiomyomas during this period had a lipoleiomyoma. The mean and median patient age was 54 and 51 years, respectively. The mean and median tumor size was 4.6 and 2.1 cm, respectively. Forty-three (83%) tumors were located in the uterine corpus, and 7 (13%) were in the cervix. One broad ligament tumor and one retroperitoneal tumor were also studied. The mitotic index was zero for all tumors. No tumors displayed cytological atypia, necrosis, calcification, or other degenerative changes. Follow-up periods ranged from 1.8 to 7.5 years (mean, 5.0 years). Four patients died of unrelated causes. There were no recurrences or fatalities related to tumor. Lipoleiomyoma of the uterus seems to have an uneventful clinical course and can now be confidently regarded as benign.

Plexiform lipoleiomyoma of the uterus: first case report

We describe the first report of plexiform lipoleiomyoma with amyloid stroma. A 57-year-old woman underwent an abdominal hysterectomy for methrorragia. The hysterectomy specimen exhibited a soft, rubbery, encapsulated 11 cm ovoid mass with aciniform, white cut surface on the right edge of the uterus. The histology was distinctive and typical of plexiform lipoleiomyoma: long cords, strands and small nests of cells embedded in a collagenous matrix. The neoplastic cells showed eosinophilic cytoplasm, crumpled, bland nuclei. Scattered islands of mature adipocytes were distributed throughout the leiomyomatous proliferation. Immunohistochemistry showed positivity for smooth muscle actin in the plexiform component, and for S100 in the adipocytes. Histogenesis and origin of the cellular neoplastic component are discussed.

Angiomyolipoma of the uterus associated with tuberous sclerosis: case report and review of the literature

BACKGROUND

Angiomyolipoma (AML) is a rare benign tumor that occurs most commonly in the kidney. Only a few cases have been described in the uterus.

CASE

We describe a 32-year-old woman with tuberous sclerosis who presented with irregular bleeding. Preoperatively, the lesions were confused with leiomyoma on ultrasound. At laparotomy, multiple circumscribed subserosal and intramural purplish lesions on the corpus uteri were noted leading to a diagnosis of uterine angiomyolipoma with the histological and immunohistochemical findings.

CONCLUSION

In contrast to other reported uterine angiomyolipoma cases, HMB-45 melanoma-specific antibody immunoreactivity is demonstrated in the present case. The histopathologic diagnosis as well as immunohistochemical analysis is discussed here with a review of the literature.

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.

Sonographic evaluation of a uterine angiolipoleiomyoma

We report the case of a 51-year-old postmenopausal woman with an angiolipoleiomyoma, a rare mesenchymal uterine tumor, and describe its sonographic appearance. The clinical presentation of these invariably benign tumors often mimics that of uterine leiomyomas, making angiolipoleiomyomas difficult to diagnose correctly before histopathologic evaluation. In this case, sonography performed to determine the cause of the patient's vaginal bleeding showed a sharply marginated, brightly echogenic solid mass adjacent to the echogenic endometrium, without associated shadowing. Histopathologic examination revealed that this tumor was composed of smooth muscle, adipose tissue, fibrous connective tissue, and blood vessels. These sonographic findings, which are unusual for tumors of the uterus, suggest the diagnosis of angiolipoleiomyoma. Accurate diagnosis of these benign tumors could prevent patients from undergoing surgery and would allow appropriate counseling of patients.

Uterine angiomyolipoma: case report and review of the literature

Extrarenal angiomyolipomas (AML) have been reported at various anatomical sites, but infrequently in the gynecological region. In the uterus, only a few cases have been described. We describe a uterine angiomyolipoma occurring in a 40-year-old woman without evidence of tuberous sclerosis. The tumor arose on the right wall of the uterine body and was partially cystic, and it was associated with marked degeneration. It was composed of mature adipose tissue, anomalous blood vessels and non-vascular smooth muscle cells. Immunohistochemistry revealed that non- vascular smooth muscle cells were positive for alpha-smooth muscle actin (alpha-SMA), desmin, vimentin, antihuman muscle actin (HHF35) and progesterone receptor (PR), and negative for cytokeratin, antihuman melanoma (HMB45), CD34, S-100 and estrogen receptor (ER). It is of particular interest that non-vascular smooth muscle cells were negative for HMB45, in contrast to renal and other extrarenal AML in which HMB45 immunoreactivity has been demonstrated in these cells.

Secretory meningioma with lipomatous component: case report

A case of meningioma coexisting with both lipomatous and secretory components, the latter characterized by hyaline inclusion bodies, is reported. The neuroradiological features of lipomeningioma are reevaluated, and the possible pathogenetic mechanisms of this unique combination in the present case are discussed.

Uterine adenolipoleiomyoma: a rare hamartomatous lesion

An apparently unique intramural uterine lesion is described for which we propose the name adenolipoleiomyoma. On gross examination, a well-circumscribed white intramural mass contained focal fatty areas. Histology showed the mass to be composed of smooth muscle, adipose tissue, and endometrial, endocervical, and tubal type glands. The endometrial glands were surrounded by typical endometrial stroma. There was no evidence of adenomyosis in the uterus outside the lesion. This is only the second report of such a lesion within the uterus and the first with an intramural location. We believe it to be a benign hamartomatous lesion.

The pathology of uterine smooth muscle tumors and mixed endometrial stromal-smooth muscle tumors: a selective review with emphasis on recent advances

This review focuses on the pathology of uterine smooth muscle tumors (SMTs), with a particular emphasis on those studies published in the past 15 years that have expanded our knowledge of these tumors which still present diagnostic challenges for the pathologist. Leiomyoma variants, leiomyosarcoma, SMTs of low or uncertain malignant potential, epithelioid SMTs, SMTs with unusual growth patterns, and mixed endometrial stromal-SMTs are discussed.

The clear cell variant of epithelioid intravenous leiomyomatosis of the uterus: report of a case

A case of very rare uterine clear cell epithelioid leiomyomatosis is reported. The patient presented with a recurrent pelvic mass after hysterectomy 2 years earlier. The recurrent tumor was located mainly in the vessels of the broad ligament as worm-like plugs. The reviewed hysterectomy specimen showed a typical multi-lobulated intramural mass together with worm-like plugs within the myometrial vessels. Computer tomography exhibited metastatic nodules in both lungs. According to an histological examination, all the tumor cells were of epithelioid type and contained abundant clear cytoplasm. Characteristic large, thick-walled blood vessels were observed. Immunohistochemical staining and ultrastructural examination supported smooth-muscle origin in this case. Electron microscopic study revealed that the clear cytoplasm was attributed to the presence of numerous dilated mitochondria that had lost their cristae. The patient is still alive with the disease 28 months after surgery.

Pure lipoma of the uterus in association with endometrial carcinoma

Pure lipoma of the uterus is a very rare entity, with few cases described in the English literature. We report the case of a 71-year-old woman, with pure lipoma of the uterus and coexistent endometrial carcinoma and discuss the possible relationship between these pathologic entities.

Uterine bizarre lipoleiomyoma

A case of uterine bizarre lipoleiomyoma occurring in a 58-year-old woman is described. A subserosal 8.5 cm mass in the posterior wall of the body had a lipoma-like appearance with strands of fibrous tissue. Histologically, the tumor predominantly consisted of adipocytes which varied in size and shape. Some cells had the appearance of signet ring cells, some had hyperchromatic nuclei, and multivacuolated lipoblasts with hyperchromatic nuclei were observed throughout the lesion. The fibrous areas showed a proliferation of smooth muscle cells with and without atypical nuclei. There was no mitotic figure. Flow cytometric analysis indicated aneuploidy. The patient was well without disease 10 months after hysterectomy. Patients with this type of tumor need a close and long-term follow-up because of the paucity of clinical information.

Metastizing low-grade clear cell leiomyosarcoma of the uterus

An unusual case of uterine clear cell tumor is reported in a 56-year-old woman. The neoplasm was identified as a peculiar low-grade leiomyosarcoma, composed mainly of watery, clear large cells with round, fairly regular nuclei. No appreciable pleomorphism or high mitotic activity was noted. There was no necrosis. The presence of occasional areas of transition between these cells and typical spindle leiomyosarcoma cells, together with the immunohistochemical results, allowed the recognition of a smooth muscle origin of this clear cell tumor. The patient was treated by hysterectomy. Six years later she developed an inguinal metastasis resembling an hibernoma, and then later developed a large retroperitoneal metastasis, which was composed entirely of clear cells and was distinguished from a liposarcoma by immunohistochemistry.

Lipoleiomyomatous tumors of the uterus: a heterogeneous group? Histopathological study of five cases

Five surgical cases of lipoleiomyomatous tumor of the uterus were studied histopathologically. All the patients were postmenopausal. Three tumors had arisen in the corpus, and the remaining two in the cervix. In four of five cases, tumors consisted of smooth muscle tissue admixed with varying amounts of mature adipose tissue, which did not show cytological atypism. In the remaining single case, the tumor contained, in addition to smooth muscle tissue and fibroadipose tissue, many anomalous arterial blood vessels, which showed an irregular, tortuous appearance resembling that found in renal angiomyolipoma. From the histopathological findings and a review of the relevant literature, it was considered that lipoleiomyomatous tumor of the uterus is not a single histopathological entity but is composed of two distinct neoplasms with different histogenesis; that is, 'lipoleiomyoma' and 'anglolipoleiomyoma'. While the latter tumor is most likely of a choristomatous nature, the former probably arises from 'lipomatous' metaplasia of a pre-existing leiomyoma.

Lipomatous tumors of the uterus. Clinico-pathological features of 10 cases with immunocytochemical study of histogenesis

The clinico-pathological and immunocytochemical findings of 10 uterine fatty tumors (1 pure lipoma and 9 lipoleiomyomas) are referred. This kind of tumor is more frequent in older postmenopausal women, treated for a preoperative diagnosis of uterine leiomyoma. Macroscopically the tumor may show different consistence and colour as a consequence of the amount of lipomatous component. The microscopical detection of areas of perivascular immature mesenchymal cells with differentiation into adipocytes supports the hypothesis of "neometaplasia" of the lipomatous component derived from immature perivascular cells. On the contrary, the evidence of multivacuolation in smooth muscular cells and the presence of muscle markers in typical mature adipocytes in lipoleiomyomas, as revealed by immunocytochemistry, suggests the hypothesis of direct transformation of smooth muscle cells into adipocytes.

Fatty change in the endometrium

Fatty change of the endometrial stroma is reported for the first time in the literature. This incidental finding further exemplifies the capacity of the endometrial stroma to undergo benign mesenchymal metaplasia.