Benign mesothelioma of the uterus. Clinical and histopathological aspects and evidence of its mesothelial origin. Apropos of 1 case

Benign mesothelioma is a rare tumor nearly always find in relation to the genital tract. We report the case of a 47-year, old woman admit in the gynecologic department for metrorragia. The tumor was composed of irregular tubules between smooth muscle cells, lined by flattened or cuboidal cells without nuclear atypia or mitoses. The tumor cells express cytokeratins and vimentin. Histologically, differential diagnosis can be made with adenocarcinoma or vascular proliferation like lymphangioma, hemangioma or angiomyoma. Clinical outcome is always favourable without recurrence or malignant transformation.     

Uterine bizarre epithelioid lipoleiomyoma with a myxoid stroma

The first case of uterine bizarre epithelioid lipoleiomyoma with a myxoid component occurring in an 86-year-old woman is described. An intramural 22 cm mass in the anterior wall of the uterine body had a lipoma-like appearance with strands of fibrous tissue. Histologically, the tumor consisted of adipocytes which varied in size and shape, and epithelioid smooth muscle cells with nuclear atypia within a myxoid stroma. No mitotic features were noted despite an extensive search. The patient was well without disease 24 months after hysterectomy. Patients with this type of tumor need close and long-term follow-up because of the paucity of clinical information.     

PTEN, tau-AP-3, thymidylate synthase immunohistochemistry scoring expression in patients with uterine leiomyomas, uterine smooth muscle tumors of uncertain malignancy potential and uterine leiomyosarcomas

Uterine smooth muscle tumors are frequently classified as benign and malignant. However, an assortment of mitotic counts and nuclear atypia can be indecisive between uncertain malignant potential, and malignant uterine smooth muscle tumors. We applied three immunohistochemical parameters to distinguish between cases of benign, malignant, and those with uncertain malignant histology.     

Adenomyofibroma of the endometrium with skeletal muscle differentiation.

A case of adenomyofibroma with skeletal muscle differentiation is described. A 55-year-old asymptomatic woman had atypical glandular cells of undetermined significance on a routine Papanicolaou smear. The endometrial biopsy revealed fragments composed of benign endometrial glands and myofibromatous stroma with foci of skeletal muscle differentiation. The stroma exhibited focal mild cytologic atypia and hypercellularity without periglandular cuffing or mitoses. Electron microscopy and immunohistochemical staining for myoglobin confirmed the skeletal muscle differentiation. A diagnosis of low-grade adenosarcoma with heterologous differentiation was made in the biopsy specimen based on the atypical stroma, the skeletal muscle differentiation, and previous observations that adenosarcomas may contain bland areas indistinguishable from an adenofibroma. The patient underwent hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy. The hysterectomy specimen revealed small foci of residual tumor. In light of these findings the diagnosis was revised to adenomyofibroma with skeletal muscle differentiation. Uterine adenomyofibroma with skeletal muscle differentiation should be distinguished from a low-grade adenosarcoma in an endometrial biopsy.     

Epithelioid vascular leiomyoma of the uterus mimicking glomangiomyoma

Case report: An unusual case of epithelioid vascular leiomyoma mimicking glomangiomyoma arising in the uterine corpus of a 55-year-old Japanese woman is presented. The surgically resected uterine mass, measuring 4.0 × 3.5 cm², demonstrated a dark red well-circumscribed tumor. Histologically, the rounded epithelioid cells around the dilated vessels showed gradual transition to spindled smooth muscle cells. Immunohistochemistry was positive for smooth muscle actin, but negative for collagen IV. Conclusion: The experience in this case emphasizes that glomangiomyoma-like feature is interesting and might indeed be a new histological variant of uterine leiomyomas.     

Mesenchymal tumors of the uterine corpus with heterologous and hematopoietic components: a study of ten cases and review of the literature

OBJECTIVE: To study the histopathological features of mesenchymal tumors of the uterine corpus with heterologous and hematopoietic components, and review their histogenesis and differential diagnosis from other neoplastic and non-neoplastic lesions. METHODS: Ten cases of mesenchymal tumors of the uterine corpus, massively infiltrated by hematopoioetic cells, or composed of other benign heterologous elements (adipose tissue in the present cases) were retrieved from the archival files of our laboratory and studied histopathologically. Immunohistochemistry was applied in selected cases. RESULTS: Six of our studied cases were diagnosed as leiomyomas, two as lipoleiomyomas, one as a symplastic lipoleiomyoma, and one as an endometrial stromal tumor. The leiomyomas were massively infiltrated by lymphocytes (5 cases) or eosinophils (one case). Immunohistochemical study of the leiomyomas with massive lymphocytic infiltration revealed the presence of a predominantly B-cell population within the infiltrate, which was polyclonal in nature. The endometrial stromal tumor was severely infiltrated by histiocytes, and was positive for vimentin, CD10, PgR and negative for actin, desmin, ER and caldesmon. CONCLUSION: The presence of hematopoietic or heterologous elements within an otherwise bland uterine leiomyoma or endometrial stromal tumor may give rise to diagnostic difficulties. Regularity of the tumor margins, low mitotic activity and absence of nuclear atypia or necrosis should be established for the exclusion of a malignancy. In the presence of massive lymphocytic infiltration of a leiomyoma the clonality of the infiltrate may aid in differentiating it from a malignant lymphoma. The pathogenesis and clinical significance of these rare neoplasms remain to be clarified.     

Epithelioid angiomyolipoma of the ovary: a case report and literature review.

Angiomyolipoma (AML) is a benign mesenchymal neoplasm that mainly occurs in the kidney either sporadically or in patients with tuberous sclerosis complex (TSC). Extrarenal AML is uncommon. We describe a 39-year-old female with a history of TSC and bilateral multicentric renal AML who presented with a persistent cystic ovarian mass that fluctuated in size during 2 years of ultrasonographic observation before its removal by salpingo-oophorectomy. The 4.5-cm mass was solid and cystic and tan-yellow. Microscopic examination showed an admixture of epithelioid cells, smooth muscle bundles, large thick-walled blood vessels, and mature adipose tissue. The epithelioid cells had abundant eosinophilic cytoplasm and many had bizarre atypical nuclei including multinucleated forms. Mitoses were rare. Typical smooth muscle cells and the epithelioid cells were strongly immunoreactive for HMB-45. To our knowledge, this represents the first report of an AML arising in the ovary. The differential with other oxyphilic tumors of the ovary is discussed.     

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.     

Uterine Angiomyolipoma Associated with Pregnancy

Uterine angiomyolipomas are rare lesions composed of mature adipose tissue, smooth muscle, fibrous connective tissue, and blood vessels in varying proportions. We reported the first case of angiomyolipoma associated with a normal pregnancy. Initially, the tumor developed intramurally and could have been confused with a partial molar gestation. After delivery, tumor development was extensive and subserosal, making differential diagnosis from a sarcoma difficult. The question of histological diagnosis, as well as that of immunocytochemical analysis which seems to be helpful in such cases, is discussed here.     

Leiomyosarcoma arising in a lipoleiomyoma

A leiomyosarcoma arising in a uterine lipoleiomyoma is described in a 70-year-old woman. The tumor measured 11 cm and was located in the corpus uteri. It was composed of a mixture of firm, pale tan, whorled tissue and soft, white or hemorrhagic areas. Histologically, the firm tissue was a mixture of bland smooth muscle, fat and fibrous tissue, whereas the soft areas showed a malignant spindle cell tumor with smooth muscle differentiation. Pure sarcoma similar to the malignant portion of the lipoleiomyoma had metastasized to the vaginal wall.     

Etiology,Pathogenesis, and Malignant Potential of Uterine Leiomyoma – A Review

In uterine smooth muscle tumors (SMT), benign leiomyoma (LM) consist of smooth muscle cells, side population cells, and fibroblasts acting together within a network regulating cell proliferation and production of extracellular matrix molecules. Chromosomal alterations, activation of the WNT/ß-catenin pathway, and overexpression of genes of the HMG group are important pathogenetic steps. The features of malignancy are tumor cell necrosis (TCN), cytological atypia, and mitotic activity. However, hormones and hypoxic stress induce reactive mitotic activity. Therefore, the mitotic index by itself is not an independent predictor of malignancy. SMT with mitotic activity up to 15 mitoses/10 HPF in the absence of atypia and TCN are designated mitotically active LM. These tumors are mostly benign. SMT with cytological atypia and a mitotic count below 10 figures /10 HPF without TCN are classified as atypical LM. Tumors with questionable TCN or without TCN and atypia but with a mitotic activity of > 15 figures/10 HPF belong to the SMT of “uncertain malignant potential”. In the presence of definite TCN, LMS are diagnosed irrespective of mitotic count. In the absence of TCN, a mitotic activity of ≥ 10 figures /10 HPF and severe atypia argue for LMS. Uterine LMS are not graded. Whether uterine LMS arise from LM or de novo is still debated, although molecular studies suggest that both are formed through distinct molecular pathways.     

A review and update of morphologically bland vulvovaginal mesenchymal lesions.

Vulvovaginal mesenchymal lesions composed of morphologically bland spindle-shaped cells often pose a particular diagnostic problem for the surgical pathologist not only because of the rarity of these lesions but also because of the wide array of entities with overlapping morphologic features. Included in this group of lesions are soft tissue neoplasms that may arise at any site and those that are characteristic of, or relatively specific to, the vulvovaginal region. Lesions that are relatively specific to the vulvovaginal region include well-known neoplasms such as aggressive angiomyxoma and angiomyofibroblastoma as well as more recently described lesions such as cellular angiofibroma and superficial cervicovaginal myofibroblastoma. Fibroepithelial stromal polyp, superficial angiomyxoma, and smooth muscle neoplasms also can occur in, but are not specific to, this site. In this review, the clinicopathologic features of these lesions are described with an emphasis on recent developments. The value of ancillary studies, especially immunohistochemistry, is discussed, although it is stressed that in general these are of limited value and routine morphology remains the mainstay in diagnosis. Morphologically bland spindle cell lesions that are not characteristic of the vulvovaginal region, but which also may occur here, are briefly discussed as are a variety of extremely rare mesenchymal lesions that have recently been described at this site.     

Cytologic features of malignant ovarian monodermal teratoma with an ependymal component in peritoneal washings.

A case of malignant neuroectodermal tumor of the ovary (monodermal teratoma) with a predominant ependymal component in the peritoneal washings of a 27-year-old woman obtained on second-look laparotomy is presented and discussed. The smear and cell block preparations showed sheets and clusters of cells containing oval nuclei with finely granular chromatin and small nucleoli. The cell nuclear/cytoplasmic ratio was within normal limits, and minimal cytologic atypia was observed. The clusters were rimmed by columnar-oriented cells lined by cilia. This is the first reported case of this rare ovarian neoplasm present on fluid cytology. Its bland cytologic appearance could be confused with endosalpingiosis.     

Report of an unusual problematic uterine smooth muscle neoplasm, emphasizing the prognostic importance of coagulative tumor cell necrosis

Follow-up data of the clinical behavior of uterine smooth muscle tumors with low malignant potential are scarce. We present a woman suffering from a uterine smooth muscle cell tumor with increased cellularity, absence of significant atypia, and two to three mitotic figures per 10 HPFs but with minimal focal coagulative tumor cell necrosis (CTCN). These microscopic features are currently accepted to label the lesion as a "smooth muscle neoplasm of low malignant potential, limited experience." After a disease-free survival of 4 years, two retroperitoneal tumors around the iliac vessels were extirpated. Both tumors consisted of smooth muscle cells with mild to moderate atypia and a mitotic index of 5-10 per 10 HPFs but with multifocal and extensive CTCN. These microscopic features were sufficient to establish the diagnosis of leiomyosarcoma. This case adds to the limited experience of the clinical behavior of problematic uterine smooth muscle cell neoplasms and underscores the prognostic importance of CTCN.     

Intraepithelial mucinous carcinoma arising in an endocervical-type mucinous polypoid adenomyoma of the uterine corpus: a case report

BACKGROUND: Benign endocervical-type mucinous adenomyoma arising in the uterine corpus is a rare entity. We report a case of intraepithelial mucinous adenocarcinoma arising in an endocervical-type mucinous adenomyoma of the uterine corpus in a previously healthy woman. CASE: A 55-year-old, white woman presented with postmenopausal bleeding. Uterine leiomyomas and endometrial polyps were suggested by ultrasonography. Endometrial curettage showed multiple polypoid tissue fragments, each composed of glands lined with tall columnar endocervical-type mucinous epithelium lying within a background of endometrial-type stroma and smooth muscle fibers. The mucinous glandular epithelium showed a spectrum of architectural and cytologic changes ranging from benign to severe atypia and occasional back-to-back cribriform glands, consistent with adenocarcinoma. The surrounding smooth muscle fibers and endometrial stromal cells were benign. A diagnosis was made of intraepithelial adenocarcinoma arising in a mucinous adenomyoma in the uterine corpus. CONCLUSION: Endocervical-type mucinous adenomyoma, although previously reported as a benign entity, may contain areas of adenocarcinoma.     

Uterine adenomyomas excluding atypical polypoid adenomyomas and adenomyomas of endocervical type: a clinicopathologic study of 30 cases of an underemphasized lesion that may cause diagnostic problems with brief consideration of adenomyomas of other female genital tract sites.

We report 30 uterine tumors composed of an admixture of endometrioid glands, endometrioid stroma, and smooth muscle that lacked the characteristic features of atypical polypoid adenomyoma. The patients ranged from 26 to 64 (median 47) years of age. The usual presenting symptom was abnormal vaginal bleeding, which was "massive" in two patients. Six patients were treated by polypectomy only, with hysterectomy performed in the remainder. Twenty-seven adenomyomas were in the corpus (22 submucosal, two mural, and three subserosal) and three in the cervix. The subserosal and submucosal examples were polypoid. The tumors were 0.3 to 17 cm in greatest dimension, and firm with cystic areas often present on sectioning. Focal hemorrhage was described in five cases. On microscopic examination, the tumors were composed of glands and cysts lined by endometrial-type epithelium separated by endometrial stroma and smooth muscle, with smooth muscle predominating. Minor foci of tubal-type epithelium (14 cases), mucinous endocervical-type epithelium (2 cases), and squamous epithelium (1 case) were present. The smooth muscle component was cellular in three cases and contained occasional bizarre nuclei in three cases. The epithelial cells were uniformly bland. No mitotic activity was observed in the epithelial or mesenchymal elements in 20 cases. In the remainder, up to 5 mitotic figures/10 high-power fields were observed in the epithelium (3 cases), the stroma and smooth muscle (3 cases), or both compartments (4 cases). Follow-up in 14 cases revealed no recurrence or extrauterine spread in any case. A diagnosis of adenocarcinoma or adenosarcoma was entertained by the submitting pathologist in five of 14 consultation cases. Adenomyomas are unusual benign uterine tumors that can be misdiagnosed, in part, because the lesion has not often received attention in the literature. The most realistic considerations in the differential diagnosis are atypical polypoid adenomyoma and adenosarcoma. The former, by definition, has epithelial atypia and the latter a malignant (usually low grade) stromal component with typically absent or inconspicuous smooth muscle. Distinction of adenomyoma from adenosarcoma may have significant therapeutic implications, particularly in young women.     

Malignant phyllodes tumor with differentiation to liposarcoma. A report of a case and bibliographic review

Phyllodes tumor represents less than 1% of breast tumors and 2 to 3% of the fibroepithelial tumors. The malignancy characteristics are the excessive growth and the stromal atypia with numerous mitosis. The stromal component of the phyllodes tumor has potential to cause metaplasia to bone tissue, cartilage, and to smooth and striated muscle, including their respective malignant neoplasms. The liposarcomatous differentiation of phyllodes tumor is extremely rare. We present the case of an unusual breast tumor diagnosed as phyllodes tumor, with sarcomatous changes on its stroma, which consists of pleomorfic and myxoid liposarcoma. We also comment some generalities about clinical and diagnostic aspects, as well as anatomopathological, therapeutic, and prognostic characteristics related to the current literature.     

Masson trichrome stain helps differentiate myofibroma from smooth muscle lesions in the head and neck region

BACKGROUND/PURPOSE: Myofibromas are well described in the head and neck region, but differentiating them from smooth muscle lesions is still difficult using smooth muscle immunohistochemical stains. This study evaluated the usefulness of the Masson trichrome stain in differentiating myofibromas from smooth muscle lesions in the head and neck region. METHODS: Samples of 11 oral myofibromas, two leiomyomas, one angioleiomyoma, and one smooth muscle hamartoma were retrieved from our archives. Immunohistochemistry and Masson trichrome stains were performed on tissue sections of these lesions. RESULTS: All 11 oral myofibromas, seven from male patients and four from female patients, were solitary myofibromas. The patients' mean age at diagnosis was 32.8 years. Oral myofibromas occurred most commonly on the gingiva (four cases) and in the mandible (three cases). With the Masson trichrome stain, the smooth muscle cell cytoplasm was stained red, while the collagenous fibrous tissue was stained blue. Myofibromas and smooth muscle lesions demonstrated different characteristic patterns with the Masson trichrome stain. Myofibromas were composed of a much more collagenous stroma intermixed with the spindle cells. Thick fibrous bundles with random, irregularly intersecting angles were prominent in myofibromas. Smooth muscle lesions showed only minimal delicate fibrous tissue surrounding the smooth muscle cells and in the septa between the smooth muscle masses. On low-power view, red masses of smooth muscle tumor surrounded by blue fibrous tissue were observed. CONCLUSION: The Masson trichrome stain can be a useful tool to differentiate myofibromas from smooth muscle lesions, but immunohistochemical methods to rule out other spindle cell lesions are still needed.     

子宫交界性平滑肌瘤的病理诊断及临床特征

在子宫平滑肌瘤与肉瘤之间存在一组交界性肿瘤，包括子宫富于细胞型，奇异型，核分裂活跃型，不典型及恶性潜能未定型平滑肌瘤。本研究对原诊断为子宫富于细胞型平滑肌效４２例，进行重新诊断，同时收集其临床资料并随访。结果：４２例中，富于细胞型平滑肌瘤５例，奇异型平滑肌瘤１例，不典型平滑肌瘤７例，恶性潜能未定型平滑肌瘤２例，肉瘤１例及普通平滑肌瘤２６例。在细胞丰富的基础上，细胞异型与核分裂的关系密切；不同月经周     

Koilocytotic atypia of the cervix.

Koilocytotic atypia was found in 217 of 858 cervical biopsies obtained during a 26-month period. Koilocytotic change was more common in younger women. Nuclear atypia in the koilocytotic cells was associated with cervical dysplasia in a high proportion of cases. There was a significant difference in the incidence of dysplasia in koilocytosis with marked nuclear atypia when compared to koilocytosis without nuclear atypia. In some cases koilocytosis was associated with vesicular changes in the cervical epithelium. The significance of this change and its association with other abnormalities of the cervix is discussed.