PLAG1 gene fusions were recently identified in a subset of uterine myxoid leiomyosarcomas (M-LMS). However, we have encountered cases of PLAG1-rearranged uterine sarcomas lacking M-LMS-like morphology and/or any expression of smooth muscle markers. To better characterize their clinicopathologic features, we performed a multiinstitutional search that yielded 11 cases. The patients ranged in age from 34 to 72 years (mean, 57 years). All tumors arose in the uterine corpus, ranging in size from 6.5 to 32 cm (mean, 15 cm). The most common stage at presentation was pT1b (n = 6), and 3 cases had stage pT1 (unspecified), and 1 case each presented in stages pT2a and pT3b. Most were treated only with hysterectomy and adnexectomy. The follow-up (range, 7-71 months; median, 39 months) was available for 7 patients. Three cases (7-21 months of follow-up) had no evidence of disease. Three of the 4 remaining patients died of disease within 55 to 71 months, while peritoneal spread developed in the last patient, and the patient was transferred for palliative care at 39 months. Morphologically, the tumors showed a high intertumoral and intratumoral heterogeneity. M-LMS-like and epithelioid leiomyosarcoma-like morphology were present in 3 and 5 primary tumors, respectively, the remaining mostly presented as nondescript ovoid or spindle cell sarcomas. Unusual morphologic findings included prominently hyalinized stroma (n = 3), adipocytic differentiation with areas mimicking myxoid liposarcoma (n = 2), osteosarcomatous differentiation (n = 1), and undifferentiated pleomorphic sarcoma-like areas (n = 1). The mitotic activity ranged from 3 to 24 mitoses per 10 high-power fields (mean, 9); 3 of 10 cases showed necrosis. In 3 of 11 cases, no expression of smooth muscle actin, h-caldesmon, or desmin was noted, whereas 5 of 5 cases expressed PLAG1. By RNA sequencing, the following fusion partners were identified: PUM1, CHCHD7 (each n = 2), C15orf29, CD44, MYOCD, FRMD6, PTK2, and TRPS1 (each n = 1). One case only showed PLAG1 gene break by fluorescence in situ hybridization. Our study documents a much broader morphologic spectrum of PLAG1-rearranged uterine sarcomas than previously reported, encompassing but not limited to M-LMS-like morphology with occasional heterologous (particularly adipocytic) differentiation. As it is currently difficult to precisely define their line of differentiation, for the time being, we suggest using a descriptive name "PLAG1-rearranged uterine sarcoma."
- MeSH
- DNA vazebné proteiny * genetika MeSH
- dospělí MeSH
- fenotyp MeSH
- genová přestavba * MeSH
- imunohistochemie MeSH
- leiomyosarkom * genetika patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádorové biomarkery genetika MeSH
- nádory dělohy * genetika patologie MeSH
- sarkom * genetika patologie MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
Leiomyosarcoma with adipocytic differentiation or lipoleiomyosarcoma is an uncommon sarcoma of the female genital tract with only a few individual reports in the literature. We therefore performed a morphologic, immunohistochemical, MDM2 gene amplification and RNA and DNA sequencing analysis of a series of gynecologic lipoleiomyosarcoma to better define the clinicopathologic spectrum. Six tumors from 6 patients were identified and classified as spindled lipoleiomyosarcoma (n = 2), mixed spindled and myxoid lipoleiomyosarcoma (n = 1), epithelioid lipoleiomyosarcoma with focal myxoid features (n = 1) and mixed spindled and epithelioid lipoleiomyosarcoma (n = 2). Patient age ranged from 41 to 64 years (mean: 49; median: 50). Primary location included uterine corpus (3), uterine corpus/cervix (2) and broad ligament (1). Tumor size ranged from 4.5 to 22 cm (mean: 11.2; median: 9.8). Four patients had metastasis at presentation or subsequently developed recurrent or distant disease. Patient status was known for 5: 2 dead of disease, 2 alive with disease and 1 alive without evidence of disease. Immunohistochemical expression of smooth muscle markers, ER, PR and WT-1 showed patterns similar to non-adipocytic gynecologic leiomyosarcomas. MDM2 amplification fluorescence in situ hybridization performed on 2 tumors was negative in 1 and equivocal in 1. Sequencing studies performed on 3 tumors found TP53 mutations in 3, with 1 tumor also having an ATRX alteration. No gene fusions were identified. Although lipoleiomyosarcomas have a diverse morphologic spectrum, our findings suggest the smooth muscle component shares morphologic and immunohistochemical features with female genital tract non-adipocytic leiomyosarcomas. Lipoleiomyosarcomas also have genetic alterations associated with non-adipocytic gynecologic leiomyosarcomas.
- MeSH
- dospělí MeSH
- hybridizace in situ fluorescenční MeSH
- imunohistochemie MeSH
- leiomyosarkom * patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- molekulární biologie MeSH
- nádor z hladké svalové tkáně * patologie MeSH
- nádorové biomarkery genetika analýza MeSH
- protoonkogenní proteiny c-mdm2 genetika MeSH
- ženské pohlavní orgány chemie patologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Leiomyomas with adipocytic differentiation typically occur in the uterus although they may arise at several sites in the female genital tract. While these are most commonly spindled leiomyomas with a component of adipocytic tissue ("conventional lipoleiomyomas"), there is a relatively ill-defined assortment of leiomyoma variants with adipocytic differentiation. We performed a morphologic, immunohistochemical and MDM2 gene amplification analysis of a large series of gynecologic leiomyomas with adipocytic differentiation to better define the clinicopathologic spectrum. Forty four tumors from 44 patients were identified and classified as conventional lipoleiomyoma (n = 21), adipocyte-rich lipoleiomyoma (defined as tumor volume >80 % adipocytes, n = 9); cellular lipoleiomyoma (n = 9); hydropic lipoleiomyoma (n = 3); and lipoleiomyoma with bizarre nuclei (n = 2). Patient age ranged from 32 to 83 years (mean 63; median 63). Primary location included uterine corpus (35), uterine cervix (3), uterine corpus/cervix (1), broad ligament (2), parametrium (2), and round ligament (1). Tumor size was 0.6-30 cm (mean 8; median 6). None of the 34 patients with follow up developed further disease (range 1-311 months; mean 65; median 41). Immunohistochemical expression of ER, PR, HMB45, Melan A, Cathepsin K and WT-1 in lipoleiomyomas and variants was similar to patterns in non-adipocytic gynecologic leiomyomas. MDM2 amplification fluorescence in situ hybridization performed on 14 tumors was negative in all. Our findings suggest female genital tract conventional lipoleiomyomas and lipoleiomyoma variants largely parallel their non-adipocytic counterparts in morphology and immunophenotype, and may be categorized using non-adipocytic leiomyoma histologic criteria.
- MeSH
- dospělí MeSH
- hybridizace in situ fluorescenční MeSH
- leiomyom * patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- lipom * genetika patologie MeSH
- nádor z hladké svalové tkáně * MeSH
- nádory dělohy * patologie MeSH
- protoonkogenní proteiny c-mdm2 genetika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- uterus patologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Lipoblastoma-like tumor (LLT) is a benign soft tissue tumor demonstrating mixed morphologic features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma but lacking genetic alterations associated with those tumors. LLT was originally thought to be specific to the vulva but has since been reported in the paratesticular region. The morphologic features of LLT overlap with those of "fibrosarcoma-like lipomatous neoplasm" (FLLN), a rare, indolent adipocytic neoplasm considered by some to form part of the spectrum of atypical spindle cell and pleomorphic lipomatous tumor. We compared the morphologic, immunohistochemical, and genetic features of 23 tumors previously classified as LLT (n = 17) and FLLN (n = 6). The 23 tumors occurred in 13 women and 10 men (mean age, 42 years; range, 17 to 80 years). Eighteen (78%) cases arose in the inguinogenital region, whereas 5 tumors (22%) involved noninguinogenital soft tissue, including the flank (n = 1), shoulder (n = 1), foot (n = 1), forearm (n = 1), and chest wall (n = 1). Microscopically, the tumors were lobulated and septated, with variably collagenized fibromyxoid stroma, prominent thin-walled vessels, scattered univacuolated or bivacuolated lipoblasts, and a minor component of mature adipose tissue. Using immunohistochemistry, 5 tumors (42%) showed complete RB1 loss, with partial loss in 7 cases (58%). RNA sequencing, chromosomal microarray, and DNA next-generation sequencing study results were negative for significant alterations. There were no clinical, morphologic, immunohistochemical, or molecular genetic differences between cases previously classified as LLT or FLLN. Clinical follow-up (11 patients [48%]; range, 2-276 months; mean, 48.2 months) showed all patients were alive without disease, and only one patient had experienced a single local recurrence. We conclude that LLT and FLLN represent the same entity, for which "LLT" seems most appropriate. LLT may occur in either sex and any superficial soft tissue location. Careful morphologic study and appropriate ancillary testing should allow for the distinction of LLT from its potential mimics.
- MeSH
- dospělí MeSH
- fibrosarkom * MeSH
- lidé MeSH
- lipoblastom * genetika MeSH
- lipom * genetika patologie MeSH
- liposarkom * genetika MeSH
- molekulární biologie MeSH
- myxoidní liposarkom * MeSH
- nádorové biomarkery genetika MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Lipoblastoma-like tumor of the vulva was first described as a benign mesenchymal neoplasm of adipocytic differentiation having features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma. Prior studies of lipoblastoma-like tumor have evaluated PLAG1, HMGA2, and RB1 immunohistochemistry and DDIT3 rearrangement status, with results supporting its distinction from lipoblastoma and myxoid liposarcoma. However, absent RB1 expression was reported in a majority of tested cases, suggesting that lipoblastoma-like tumor may have underlying 13q alterations and be related to RB1-deleted soft tissue tumors. To further understand the molecular genetics of lipoblastoma-like tumor, we examined 7 cases by RB1 immunohistochemistry, DDIT3 and PLAG1 break apart FISH probes, RB1 enumeration FISH probe, and genomic copy number analysis by microarray. Patient age ranged from 21 to 56 years (median 35 years). Clinical follow up was available for 5 patients (71%) ranging 3-264 months (median 74 months). Microscopically, lipoblastoma-like tumor formed large lobules separated by thin and/or thick bands of fibrous tissue and had a prominent network of thin-walled vessels. Each tumor was predominantly composed of spindle cells and lipoblasts with variable quantities of mature adipocytes. RB1 immunohistochemistry exhibited a heterogeneous or "mosaic" pattern of weak and negative nuclear expression in all seven cases. DDIT3 and PLAG1 FISH were negative in each case. No evidence of RB1 regional gain or loss was identified by FISH. Genomic copy number analysis by chromosomal microarray showed a normal diploid profile in six tumors (86%). One tumor had copy number abnormalities consisting of an 11.9 megabase deletion from 1p13.3 to 1p11.2 and monosomy 14. Although lipoblastoma-like tumor has features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma, it is genetically different from these tumors. Furthermore, lipoblastoma-like tumor does not appear to have structural abnormalities of 13q resulting in deletion of RB1.
- MeSH
- dospělí MeSH
- genová dávka MeSH
- hybridizace in situ fluorescenční MeSH
- imunohistochemie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- nádory vulvy genetika patologie MeSH
- nádory z pojivové a měkké tkáně genetika patologie MeSH
- stanovení celkové genové exprese MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH