A Case Report of Occult Breast Cancer Detected by Diagnostic Laparoscopy for Suspected Ovarian Cancer.

Diagnostic laparoscopy is useful in the management of gynecological cancers; however, it can occasionally result in the detection of other malignancies. Occult breast cancer (OBC) is metastatic breast cancer without a recognized primary breast lesion. We report a rare case of OBC that was detected laparoscopically. A 64-year-old female presented to our hospital with back pain. Magnetic resonance imaging (MRI) revealed a 50 mm multicystic tumor with an internal nodule in the right ovary. Positron emission tomography/computed tomography showed abnormal accumulation in multiple lymph nodes, moderate accumulation in the ovarian tumor nodule, and no accumulation in the breasts. Ovarian cancer was suspected, and a diagnostic laparoscopy was performed. Laparoscopically, a cystic tumor in the right ovary and 10 mm nodule in the right round ligament were observed and partially resected. Immunohistopathologically, the nodules of the round ligament exhibited features consistent with those of breast cancer, but the ovarian tumor was a seromucinous borderline tumor. MRI revealed no breast lesions. Therefore, the malignancy was diagnosed as an OBC.

Myxoid liposarcoma with nuclear pleomorphism: a clinicopathological and molecular study.

Myxoid liposarcoma (MLS) is a common type of liposarcoma. It is characterized by variably lipogenic uniform cells in myxoid stroma with arborizing capillaries and DDIT3 fusion. Nuclear uniformity is the rule, which is maintained even in high-grade round cell examples. In this study, we conducted an in-depth investigation of four MLS tumors that demonstrated nuclear pleomorphism in three patients. These cases accounted for 2.1% of 142 patients with MLS. All patients were male aged 26, 33, and 49 years. Nuclear pleomorphism was observed in both primary and metastatic tumors in one patient, a primary tumor in one patient, and a metastatic tumor in another patient. Pleomorphism was severe in three tumors and moderate in one. Histology resembled that of dedifferentiated liposarcoma with myxoid features, pleomorphic liposarcoma with myxoid features, or myxoid pleomorphic liposarcoma in two tumors, pleomorphic sarcoma with focal cartilaginous and rhabdomyoblastic differentiation in one tumor, and epithelioid pleomorphic liposarcoma in one tumor. All tumors harbored FUS::DDIT3 fusions and immunohistochemically expressed DDIT3. All tumors had TP53 mutations, whereas previous specimens with uniform cytology from the same patients lacked TP53 mutations. One tumor showed RB1 deletion and complete loss of Rb expression, which was unclassifiable using DNA methylation-based methods. The rare occurrence of nuclear pleomorphism is underrecognized in MLS and increases the complexity to the diagnosis of liposarcoma. DDIT3 evaluation can be liberally considered in liposarcoma assessment even in the presence of nuclear pleomorphism.

Activated Akt expression is associated with the recurrence of primary melanomas and further refines the prognostic and predictive values for relapse in acral melanomas.

A PTEN deficiency leads to the activation of phospho-Akt at serine 473 (p-Akt) and promotes the tumorigenesis of melanomas by coupling with NUAK2 amplification. We tested the prognostic impact of p-Akt and/or NUAK2 expression on the relapse-free survival (RFS) and overall survival (OS) of melanoma patients. Primary tumors from patients with acral melanomas (112), Low-cumulative sun damage (CSD) melanomas (38), and High-CSD melanomas (18) were examined using immunohistochemistry and their prognostic significance was analyzed statistically. The expression of p-Akt was found in 32.1%, 68.4%, and 55.6% of acral, Low-CSD, and High-CSD melanomas, while NUAK2 expression was found in 46.4%, 76.3%, and 50.0%, respectively. Either p-Akt or NUAK2 expression was inversely correlated with the RFS of primary melanoma patients and acral melanoma patients (p-Akt: p < .0001, p < .0001; NUAK2; p = .0005, p < .0001, respectively). Strikingly, multivariate analyses revealed that p-Akt had a significant impact on RFS (Hazard ratio = 4.454; p < .0001), while NUAK2 did not. Further subset analyses revealed that p-Akt expression had an inferior RFS of patients with acral melanomas (Hazard ratio = 4.036; p = .0005). We conclude that the expression of p-Akt has a significant impact on RFS of patients with primary melanomas and can predict the relapse of patients with acral melanomas.

High-grade intraductal carcinoma of the parotid gland harboring CTNNA1::ALK rearrangement: Changes in genetic status using genetic testing during treatment with an ALK inhibitor.

BACKGROUND: Salivary gland carcinomas harboring anaplastic lymphoma kinase (ALK) rearrangements are rare. Here, we present the pathological characteristics, clinical course, and changes in the genetic status of a salivary gland carcinoma harboring a catenin alpha 1 (CTNNA1)::ALK rearrangement during treatment with an ALK tyrosine kinase inhibitor (TKI). METHODS: A 59-year-old man with a parotid tumor and cervical lymph node metastases underwent total parotidectomy and radical neck dissection. One month after completion of postoperative radiotherapy, the patient experienced multiple recurrences. RESULTS: Subsequent treatment with the ALK-TKI alectinib was initially effective against the intraductal carcinoma harboring CTNNA1::ALK rearrangement and TP53 mutation. However, 10 months later the patients' condition deteriorated, and an additional phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation was detected. The patient ultimately succumbed to multiple organ failure. CONCLUSION: The clinical course suggested the concurrent emergence of TP53 and PIK3CA mutations and ALK-TKI drug-selective growth of non-ALK rearrangement gene tumor cells.

Strategic Approach to Heterogeneity Analysis of Cutaneous Adnexal Carcinomas Using Computational Pathology and Genomics.

Cutaneous adnexal tumors are neoplasms that arise from skin appendages. Their morphologic diversity and phenotypic variability with rare progression to malignancy make them difficult to diagnose and classify, and there is currently no established treatment strategy. To overcome these difficulties, this study investigated the transcription factor SOX9 expression, morphology, and genetics of skin adnexal tumors for understanding their biology, especially their histogenesis. We showed that cutaneous adnexal tumors and their nontumor counterparts of skin and appendages exhibit expression patterns similar to that of SOX9. Its expression intensity and pattern, as well as histopathologic evaluation of tumors, were analyzed using digital images of 69 normal skin adnexal 9-type organs and 185 skin adnexal 29-type tumors as references. It was possible to distinguish basal cell carcinoma from squamous cell carcinoma, sebaceous carcinoma, and pilomatrixoma with significant differences, along with porocarcinoma from squamous cell carcinoma. Furthermore, unsupervised machine learning "computational pathology" was used to derive a multiregion whole-exome sequencing fusion method termed "genocomputed pathology." The genocomputed pathology of three representable adnexal carcinomas (porocarcinoma, hidradenocarcinoma, and spiradenocarcinoma) was evaluated for total nine cases. We showed that there was more heterogeneity than expected within the tumors as well as the coexistence of components lacking driver fusion genes. The presence or absence of potential driver genes, such as PIK3CA, YAP1, and PTEN, in each region was identified, highlighting a therapeutic strategy for cutaneous adnexal carcinoma encompassing heterogeneous tumors.

Hepcidin as a key regulator of iron homeostasis triggers inflammatory features in the normal endometrium.

Menstrual blood, containing high iron levels, can undergo retrograde transport into the abdominal cavity. Excess iron causes oxidative stress and inflammation. Iron metabolism is regulated by hepcidin, and serum hepcidin levels are increased in patients with endometriosis; however, the functions of hepcidin in normal endometrium remain unclear. We therefore aimed to examine hepcidin concentrations in patients with endometriosis and to determine if iron accumulation and hepcidin increased the production of reactive oxygen species (ROS) and inflammation in normal endometrial cells. We determined hepcidin levels in peritoneal fluid and menstrual blood from patients with and without endometriosis (25/16 and 15/15 patients, respectively). We also examined the effects of hepcidin on ferroportin expression, iron accumulation, and ROS generation in normal endometrial stromal cells (NESCs) from 20 women who underwent surgery for uterine leiomyoma, using immunohistochemistry and immunofluorescence analyses and analyzed its effect on the expression of inflammatory cytokines by real-time polymerase chain reaction. There was no significant difference in iron concentrations in menstrual blood or peritoneal fluid between women with and without endometriosis; however, women with endometriosis had significantly higher hepcidin levels in menstrual blood. Hepcidin reduced the expression of ferroportin in NESCs and promoted the accumulation of ferrous iron. Hepcidin plus ferrous iron increased the production of ROS and inflammatory cytokines compared with ferrous iron alone. These results indicate that women with endometriosis have high hepcidin levels in menstrual blood, leading to increased iron production, oxidative stress, and inflammation, which may, in turn, promote the development of endometriosis.

Postoperative Pregnancy Outcomes Following Laparoscopic Surgical Management in Women with Stage III/IV Endometriosis: A Single-Center Follow-Up Study.

Objectives: The effects of laparoscopic surgical management in women with stage III/IV endometriosis remain controversial. The standard extent of resection for stage III/IV endometriosis with deep endometriosis to treat endometriosis-associated infertility is debatable. This study aimed to assess the postoperative pregnancy outcomes following a routine surgical intervention for stage III/IV endometriosis patients. Materials and Methods: Patients with stage III/IV endometriosis who underwent conservative laparoscopic surgery at our hospital between January 2010 and December 2018 were retrospectively analyzed. Statistical analyses were performed to determine the correlations between endometriosis features and postoperative pregnancy outcomes. Results: Of 256 patients enrolled, 94 wished to conceive. Exclusion criteria: ≥40 years, adenomyosis, partners with infertility issues. Finally, 71 women were included. The overall postoperative pregnancy rate was 76.1% (n = 54): 49 and five from non-assisted reproductive technology (ART) and ART, respectively. The postoperative pregnancy rate in patients diagnosed with infertility presurgery (40/71) was 70.0% (n = 28): 24 (non-ART) and four (ART). The endometriosis fertility index (EFI) score was higher in the pregnant than in the nonpregnant group (P = 0.03). The EFI score and surgical score of EFI were higher in the non-ART than in the ART group (P = 0.04; P = 0.02); in the infertile group, they were higher in the pregnant than in the nonpregnant group (P = 0.018; P = 0.027). Conclusion: Our postoperative pregnancy rate after conservative laparoscopic surgery for patients with stage III/IV endometriosis compared favorably with previous reports. EFI was a significant predictor of postoperative pregnancy. Our surgical approach to maintain a high surgical score of EFI might help treat endometriosis-associated infertility.

Correlation between L-amino acid transporter 1 expression and 4-borono-2-18 F-fluoro-phenylalanine accumulation in humans.

BACKGROUND: The correlation between L-type amino acid transporter 1 (LAT1) expression and 4-borono-2-18 F-fluoro-phenylalanine (18 F-FBPA) accumulation in humans remains unclear. This study aimed to investigate the correlation between LAT1 expression in tumor tissues and 18 F-FBPA accumulation in patients with head and neck cancer who participated in a clinical trial of 18 F-FBPA positron emission tomography (PET). METHODS: Altogether, 28 patients with head and neck cancer who participated in a clinical trial of 18 F-FBPA PET at our institution between March 2012 and January 2018 were included. Correlations between standardized uptake values (SUVs); the maximum SUV (SUVmax ), the mean SUV within a 1 cm3 sphere centered at a single point, that is, the SUVmax (SUVpeak ), the minimum SUV (SUVmin ), and the intensity of LAT1 expression (maximum and minimum LAT1 expressions) were investigated. RESULTS: Weak correlations were identified between SUVmax and LAT1 maximum score, SUVmin and LAT1 maximum score, and SUVmin and LAT1 minimum score (ρ = 0.427, 0.362, and 0.330, respectively). SUVmax and LAT1 minimum score, SUVpeak and LAT1 maximum score, and SUVpeak and LAT1 minimum score demonstrated moderate correlations (ρ = 0.535, 0.556, and 0.661, respectively). Boron neutron capture therapy (BNCT) was performed in 2 of the 4 patients with discrepancies between 18 F-FBPA accumulation and intensity of LAT1 expression, and the intensity of LAT1 expression was a better predictor of treatment response. CONCLUSION: 18 F-FBPA accumulation and the intensity of LAT1 expression demonstrated a moderate correlation; however, LAT1 expression may be a better predictor of treatment response of BNCT in patients with discrepancies.

A rare case of epithelial-myoepithelial carcinoma ex pleomorphic adenoma of the parotid gland: Radiologic-pathologic correlation.

Carcinoma ex pleomorphic adenoma is a carcinoma that arises from a primary or recurrent benign pleomorphic adenoma. The prevalence of epithelial-myoepithelial carcinoma is low, and this histological type accounting for only 1% of all salivary gland tumors. Here, we report a rare case of Epithelial-Myoepithelial Carcinoma ex pleomorphic adenoma of the parotid gland with a radiologic-pathologic correlation.

KDM2B-Rearranged Soft Tissue Sarcomas Expand the Concept of BCOR-Associated Sarcoma.

Sarcomas with BCOR genetic alterations (BCOR-associated sarcomas) represent a recently recognized family of soft tissue and bone tumors characterized by BCOR fusion, BCOR internal tandem duplication, or YWHAE::NUTM2B fusion. Histologically, the tumors demonstrate oval to spindle cell proliferation in a variably vascular stroma and overexpression of BCOR and SATB2. Herein, we describe 3 soft tissue sarcomas with KDM2B fusions that phenotypically and epigenetically match BCOR-associated sarcomas. The cases included 1 infant, 1 adolescent, and 1 older patient. All tumors showed histologic findings indistinguishable from those of BCOR-associated sarcomas and were originally diagnosed as such based on the phenotype. However, none of the tumors had BCOR or YWHAE genetic alterations. Instead, targeted RNA sequencing identified in-frame KDM2B::NUTM2B, KDM2B::CREBBP, and KDM2B::DUX4 fusions. KDM2B fusions were validated using reverse-transcription PCR, Sanger sequencing, and in situ hybridization assays. Genome-wide DNA methylation analysis matched all 3 tumors with BCOR-associated sarcomas using the Deutsches Krebsforschungszentrum (DKFZ) classifier and t-distributed stochastic neighbor embedding analysis. One localized tumor showed a flat genome-wide copy number profile, and the patient remained disease-free after treatment. The other tumors showed multiple copy number alterations, including MDM2/CDK4 amplification and/or CDKN2A/B loss, and both tumors metastasized, leading to the patient's death in one of the cases. When tested using KDM2B immunohistochemistry, all 3 KDM2B-rearranged sarcomas showed diffuse strong staining, and all 13 sarcomas with BCOR genetic alterations also demonstrated diffuse, strong, or weak staining. By contrast, among 72 mimicking tumors, only a subset of synovial sarcomas showed focal or diffuse weak KDM2B expression. In conclusion, our study suggests that KDM2B-rearranged soft tissue sarcomas belong to the BCOR-associated sarcoma family and expand its molecular spectrum. This may be related to the known molecular relationship between KDM2B and BCOR in the polycomb repressive complex 1.1. Immunohistochemical analysis of KDM2B is a potentially valuable diagnostic tool for BCOR-associated sarcomas, including those with KDM2B rearrangement.

Clinical outcomes of head and neck mucosal melanoma treated with surgery: a single-center study in Japan.

BACKGROUND: Head and neck mucosal melanomas are rare malignancies. Although the prognosis is poor owing to the high incidence of distant metastases, locoregional control remains important. It is difficult to obtain results in a large cohort because of its rarity. This study aimed to elucidate the survival outcomes of patients with head and neck mucosal melanoma treated with surgery in Japan. METHODS: Patients with head and neck mucosal melanoma who were surgically treated between 2007 and 2021 at the National Cancer Center Hospital were retrospectively analyzed. RESULTS: A total of 47 patients were included in this study. The 5-year overall survival, disease-specific survival, locoregional control and relapse-free survival rates were 42%, 50%, 79% and 13%, respectively. The disease-specific survival of the oral mucosal melanoma group was significantly better than that of the sinonasal mucosal melanoma group (5-year disease-specific survival rate: 70% versus 37%, respectively; P = 0.04). Multivariate analyses revealed that sinonasal mucosal melanoma were independently significant adverse prognostic factor, for overall survival and disease-specific survival. Patients with oral mucosal melanoma patients had a higher incidence of lymph node metastasis than those with sinonasal mucosal melanoma patients (P < 0.0001). CONCLUSION: This study demonstrated the survival outcomes of the largest cohort of patients with head and neck mucosal melanomas treated surgically at a single institution within the past 20 years in Japan. We found that survival outcomes and incidence of nodal metastases varied by site.

Clinical and pathological features of second primary neoplasms arising in head and neck reconstructive skin flaps.

The incidence of second primary neoplasms arising in the skin reconstructive flap (SNAF) is increasing because of the increase in head and neck flap reconstruction and cancer survival. Prognosis, optimal treatment, and their clinicopathological-genetic features are under debate and are difficult to diagnose. We retrospectively reviewed SNAFs based on a single center's experience over 20 years. Medical records and specimens of 21 patients with SNAF who underwent biopsies between April 2000 and April 2020 at our institute were retrospectively analyzed. Definite squamous cell carcinoma and the remaining neoplastic lesions were subclassified as flap cancer (FC) and precancerous lesions (PLs), respectively. Immunohistochemical studies focused on p53 and p16. TP53 sequencing was conducted using next-generation sequencing. Seven and 14 patients had definite FC and PL, respectively. The mean number of biopsies/latency intervals was 2.0 times/114 months and 2.5 times/108 months for FC and PL, respectively. All lesions were grossly exophytic and accompanied by inflamed stroma. In FC and PL, the incidences of altered p53 types were 43% and 29%, respectively, and those of positive p16 stains were 57% and 64%, respectively. Mutation of TP53 in FC and PL were 17% and 29%, respectively. All except one patient with FC under long-term immunosuppressive therapy survived in this study. SNAFs are grossly exophytic tumors with an inflammatory background and show a relatively low altered p53 and TP53 rate and a high p16 positivity rate. They are slow-growing neoplasms with good prognoses. Diagnosis is often difficult; therefore, repeated or excisional biopsy of the lesion may be desirable.

Genome Doubling Shapes High-Grade Transformation and Novel EWSR1::LARP4 Fusion Shows SOX10 Immunostaining in Hyalinizing Clear Cell Carcinoma of Salivary Gland.

Hyalinizing clear cell carcinoma (HCCC) is a rare indolent malignant tumor of minor salivary gland origin with EWSR1::ATF1 rearrangement. Pathologically, the tumor cells possess a clear cytoplasm in a background of hyalinized stroma. Generally, the tumor cells are positive for p63 and p40 and negative for s100 and α-smooth muscle actin, suggesting that they differentiate into squamous epithelium and not into myoepithelium. In this study, we performed a detailed histopathological and genomic analysis of 6 cases of HCCC, including 2 atypical subtypes-a case of "high-grade transformation" and 1 "possessing a novel partner gene for EWSR1." We performed a sequential analysis of the primary and recurrent tumor by whole-exome sequencing, RNA sequencing, Sanger sequencing, and fluorescence in situ hybridization to investigate the effect of genomic changes on histopathology and clinical prognosis. A fusion gene involving the EWSR1 gene was detected in all cases. Five cases, including the "high-grade transformation," harbored a known EWSR1::ATF1 fusion gene; however, 1 case harbored a novel EWSR1::LARP4 fusion gene. This novel EWSR1::LARP4-fused HCCC has a SOX10-positive staining, which is different from the EWSR1::ATF1-fused HCCC. According to whole-exome sequencing and fluorescence in situ hybridization analysis, the "whole-genome doubling" and focal deletion involving CDKN2A, CDKN2B, and PTEN were detected in HCCC with "high-grade transformation." Conclusively, we identified a novel partner gene for EWSR1, LARP4, in indolent HCCC. Importantly, "high-grade transformation" and poor prognosis were caused by whole-genome doubling and subsequent genomic aberrations.

Is neonatal uterine bleeding responsible for early-onset endometriosis?

BACKGROUND: It has been hypothesized that the origin of early-onset endometriosis could be from endometrial mesenchymal stem cells (eMSCs) in neonatal uterine blood (NUB). There is no information on the possible mechanistic basis linking an association between NUB/neonatal endometrium and development of early-onset endometriosis. In this study we performed a series of experiments to clarify the mechanistic link between NUB and/or neonatal endometrium and development of early-onset endometriosis. METHODS: We retrospectively collected postmortem neonatal endometria (n = 15) and prospectively collected NUB (n = 18) of female babies for the analysis of different biological markers including eMSCs. Immunohistochemical analysis of neonatal endometria was performed to examine the expression patterns of ovarian steroid receptors (ER/PGR), decidualization (prolactin, IGFBP1), pre-decidualization (Glycodelin A, α-SMA), proliferation (Ki-67 index), vascularity (CD31 + cells), immunocompetent CD68+, CD45+, CD56 + cells and some putative markers of eMSCs. Cell transfer method and immunocytochemistry were used to investigate the eMSCs and/or endometrial cells in NUB. RESULTS: Immunohistochemical analysis of postmortem neonatal endometria revealed variable staining response to ER/PGR, decidual markers, and substantial proliferative and angiogenic activity. A moderate to strong immunoexpression of Glycodelin-A was found in both neonatal and adult endometria. The tissue infiltration of CD56+, CD45 + and CD68 + immunocompetent cells was significantly low in neonatal endometria than that in adult endometria (p = 0.0003, p < 0.0001, p = 0.034, respectively). No eMSCs or even endometrial cells were detected in NUB. However, a variable expression of some phenotypes of eMSCs (CD90/CD105) was found in neonatal endometria. CONCLUSIONS: Based on our serial experiments we did not find any supporting evidence for the role of NUB in early-onset endometriosis. Neonatal endometria showed variable expression of ovarian steroid receptors, decidualization, and a substantial amount of proliferative and angiogenic activity. As an alternative mechanism, a significantly less tissue accumulation of immunocompetent cells in neonatal endometria may explain the survival of ER + and PGR + cells should they make entry into the pelvis and consequent development of early endometriosis with the onset of ovarian function. Future study with large sample size and application of modified technological tools is warranted to test the NUB hypothesis and to clarify their biological or clinical significance. TRIAL REGISTRATION: not applicable.

Association between tissue stress reaction and ACE2/TMPRSS2 expression in endometria of reproductive aged women before and during Covid-19 pandemic.

BACKGROUND: A potential concern has been raised regarding fertility and reproductive outcome during the Covid-19 pandemic with growing stress and anxiety. However, information on the association between tissue stress reaction and expression profiles of SARS-CoV-2 viral entry proteins, ACE2 and TMPRSS2, in endometria collected from women before (pre-pandemic) and during the Covid-19 pandemic (in-pandemic) is unknown. We aim to investigate the relationship between the expression of stress-reactive proteins and of ACE2 and TMPRSS2 in endometria collected from women during these two different time frames. METHODS: We retrospectively retrieved tissue blocks of endometrial samples from 25 women in 2019 (pre-pandemic) and 25 women in 2020 (in-pandemic) who underwent hysterectomy for different gynecological indications. Immunohistochemical analysis was performed with endometrial tissue samples that were collected before and during the pandemic, using respective antibodies targeting ACE2/TMPRSS2, ADRB2 and NK1R (stress and anxiety receptor markers, respectively). The quantification of immunoreactive cells for each marker was calculated by the immunoreactive score (IRS) analysis. This retrospective cohort study was limited to small sample size. RESULTS: No significant differences in the IRS of ACE2 and TMPRSS2 were found between the endometria that were collected before and during the pandemic with a lack of correlation between ACE2 and TMPRSS2 expression in respective endometria (r = 0.11, pre-pandemic; r = 0.04, in-pandemic). The immunostaining levels of stress marker, ADRB2 were significantly higher in the endometria of in-pandemic group (p = 0.015) comparing to that of pre-pandemic group. Pearson's correlation coefficient analysis showed a significant correlation in the expression between ADRB2 and TMPRSS2 (r = 0.41, p = 0.042) in the endometria of in-pandemic group but not in the pre-pandemic group. CONCLUSION: The rise in stress and anxiety among women during current pandemic may elicit substantial amount of tissue stress reaction with consequent increase in the expression of SARS-CoV-2 viral entry proteins in their endometria. A lack of correlation between ACE2 and TMPRSS2 expression in endometria may reassure women in their reproductive age that they are not more susceptible to infection by SARS-CoV-2 and suggest that stressful women during this pandemic can safely decide to conceive naturally or by artificial reproductive technology.

Successful resection of growing teratoma syndrome in the abdominal wall with reconstruction using tensor fascia lata muscle flap: A case report and literature review.

While cancer cure is the primary goal, fertility preservation is also a cornerstone of the underlying principle of treatment for ovarian germ cell tumors. Growing teratoma syndrome (GTS) presents with growth of mature teratomas during or after chemotherapy. We report a case of successful treatment of GTS in the anterior abdominal wall involving reconstruction. A 23-year-old woman with a suspected right ovarian mature teratoma with torsion underwent emergency laparoscopically assisted extracorporeal ovarian cystectomy. Histopathological findings revealed a grade 1 immature teratoma. After two months, postoperative α-fetoprotein (AFP) levels increased, and disseminated lesions developed not only in the pelvic cavity but also in the abdominal wound where the tumor had been extracted using an extracorporeal technique at the time of primary surgery. The patient underwent laparoscopic right salpingo-oophorectomy, excision of multiple peritoneal nodules, and biopsy of abdominal wall mass. The left rectus abdominis muscle tumor could not be removed. All of these nodules were diagnosed as metastatic immature teratomas. Although the patient received three cycles of chemotherapy, the residual tumor in the abdominal wall grew remarkably despite post-chemotherapy normalization of AFP levels. Both rectus abdominis muscles involving the residual tumors were removed and reconstructed using a left tensor fascia lata muscle flap. Histopathologically, the residual tumors were identified as mature teratomas with no immature elements, resulting in GTS. The patient got pregnant without the need of fertility treatment and gave birth uneventfully by cesarean section. Thus, reconstruction with a tensor fascia lata muscle flap facilitated complete removal of GTS while preserving fertility.