[Myxoid variant of adrenocortical carcinoma]. / Carcinome corticosurrénalien variante myxoïde : aspects clinico-pathologiques et immunohistochimiques d'une variante rare et agressive.

We report two cases of patients presenting myxoid variant of adrenocortical carcinoma (ACC). This very rare variant is characterized by a tumoral proliferation organized in trabeculae, cords or even pseudo-glands within an acellular myxoid materiel stained by Alcian Blue and negative for PAS. Tumor cells have a small to medium size and have little atypia. Their immunohistochemical profil (positivity of Synaptophysin, SF1, Melan A, Vimentin and Inhibin, with a weak or negative pancytokeratin expression) eliminate the main differential diagnoses (metastasis of a myxoid adenocarcinoma and soft tissue myxoid tumor). Many scoring systems have been proposed in order to evaluate the risk of malignancy of these lesions: the Weiss score seems less efficient to evaluate malignancy in this variant than the reticulinic algorithm or the Helsinki score. Prognosis of myxoid variant of ACC seems worse than classical ACC.

A novel case of myxoid variant of adrenocortical carcinoma in a patient with multiple endocrine neoplasia type 1.

Adrenocortical carcinoma (ACC) is a rare malignancy arising from adrenocortical parenchymal cells. Myxoid ACC is one of the newly identified, rare, but important histological variants of ACC, characterized by the presence of abundant extracellular Alcian Blue-positive myxoid material. Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant cancer predisposition syndrome, and the incidence of ACC in MEN1 patients has been reported to be between 1.4% and 6%. Here, we report the case of a 68-year-old Japanese woman harboring the past history of MEN1 associated with insulinoma, pituitary tumor, and hyperparathyroidism. She presented to our hospital with hypertension and hypokalemia. Imaging studies revealed a right adrenal tumor, and histological examination revealed myxoid ACC. Despite surgical resection of the tumor and mitotane therapy, the patient died 6 months after the surgery. To the best of our knowledge, this is the first reported case of the myxoid variant of ACC in a patient with MEN1. The patient's clinical course was characterized by the development of both multiple endocrine and non-endocrine neoplasm, hyperaldosteronism, and aggressive biological behavior. This case confirmed that myxoid morphology was also associated with aggressive behavior in ACC, but further studies are required to clarify the association between MEN1 and myxoid ACC.

12 years of fighting liposarcoma: a case report.

The proportion of liposarcoma in the structure of cancer incidence is from 10 to 35% of all mesenchymal tumors. This clinical observation describes an 12-year struggle with myxoid liposarcoma of the left upper arm, during which 17 surgeries were performed due to local recurrences, 17 radiation therapy courses and 5 chemotherapy courses were conducted. Clinical observation shows the whole complexity of myxoid liposarcoma treatment. The effectiveness of therapeutic management is determined by persistent surgery, and also by the lack of expression of Pgp, glutathione-S-transferase, metallothionein and mutant p53 in tumor structure.

Myxoid neurofibroma masquerading as lymphatic-venous malformation and poses a diagnostic challenge on fine needle aspiration biopsy.

BACKGROUND: Myxoid neurofibromas (NF) are uncommon, benign spindle cell tumors that originate from peripheral nerve sheaths, often posing a diagnostic challenge due to their hypocellularity on cytology specimens. Distinguishing myxoid spindle cell lesions can be challenging, given the broad range of potential differential diagnoses. CASE PRESENTATION: A 26-year-old female with a past medical history of embolized inguinal, flank, and retroperitoneal venolymphatic malformation presented with a left pelvic pain causing significant disability. CT scan showed an extensive 8.7 cm × 6.6 cm retroperitoneal mass. FNA was performed and alcohol-fixed papanicolaou-stained smears showed a hypocellular specimen with loosely arranged clusters of bland spindle cell proliferation in the background of a mucoid matrix. Spindle cells showed scant cytoplasm and elongated oval-shaped regular nuclei. Prominent nucleoli were not seen. An excisional biopsy revealed a bland spindle cell proliferation in a myxoid background associated with shredded collagen bundles. Immunohistochemical staining showed diffuse positivity for S100 and CD34. Based on the overall findings, a definitive diagnosis of myxoid neurofibroma was rendered. DISCUSSION: Cytological features of myxoid neurofibroma include the presence of hypocellular spindle-shaped cells arranged in small, loosely organized groups within a myxoid matrix background. Cells exhibit scant cytoplasm with regular oval and elongated nuclei. Nucleoli are typically not identified. The differential diagnosis includes myxoid neurofibroma, myxoma, myxoid liposarcoma, myxoid chondrosarcoma, myxoid dermatofibrosarcoma protuberans, low-grade fibromyxoid sarcoma, and low-grade myxo-fibrosarcoma. CONCLUSION: We aim to highlight the importance of considering myxoid neurofibroma in the differential diagnosis of hypocellular myxoid spindle cell lesions encountered on fine-needle aspiration cytology.

A patient with epithelioid pleural mesothelioma (Myxoid variant) who survived for a long period without treatment.

Pleural mesothelioma is a disease with a very poor prognosis. Here, we report a mesothelioma patient who survived for 5 years and a half. As a result of the autopsy, the tumor was diagnosed as a myxoid variant, which is internationally proposed as a histological subtype of epithelioid mesothelioma with a relatively favorable prognosis. Since patients with this disease are expected to survive for a long period even without treatment, careful determination of the therapeutic approach is considered necessary. This report is considered to be the first of a myxoid variant epithelioid pleural mesothelioma in Japan.

Intracranial Myxoid Variant of Angiomatoid Fibrous Histiocytoma: A Case Report and Literature Review.

Angiomatoid fibrous histiocytoma (AFH) is a rare and slow-growing soft tissue lesion that typically arises in the extremities of young patients. Microscopically, AFH is characterized by pseudovascular, blood-filled spaces that are surrounded by a multinodular proliferation of spindle and/or round cells and lymphoid cuffs. However, there is a wide morphological spectrum, including a myxoid variant. Examples with a prominent myxoid matrix are rare and may pose great diagnostic difficulty. Specific gene fusions have been found to play a significant role in AFH tumorigenesis. Gene fusions of Ewing sarcoma breakpoint region 1 (EWSR1) with members of the cAMP response element-binding protein family (CREB) of transcription factors (CREB1, activating transcription factor 1 (ATF1), and cAMP response element modulator (CREM)) have been described in histopathologically diverse mesenchymal neoplasms such as AFH, hyalinising clear cell carcinomas of salivary glands, primary pulmonary myxoid sarcoma, and clear cell sarcoma. Classically, EWSR1-CREB is known to be the prominent gene fusion in AFH. Recently, a small series of intracranial mesenchymal tumors with EWSR1-CREB family gene fusions has been reported. These tumors seem to show histologic, immunophenotypic, and cytogenic features similar to those observed in the myxoid variant of AFH; therefore, there is a debate on whether these tumors merely represent a variant of AFH or a novel entity. This case report is of a 58-year-old woman presenting with the first episode of generalized seizure due to an extra-axial lesion with homogenous contrast enhancement in the right parietal lobe, which was initially diagnosed as a World Health Organization (WHO) grade I meningioma. Following a series of pathological investigations, the diagnosis of an intracranial myxoid variant of AFH was made. This case report illustrates the need to consider the myxoid variant of intracranial AFH in the differential diagnosis of meningioma-like tumors. A high index of suspicion is required if the meningioma behaves abnormally with a much higher recurrence rate.

Ewing sarcoma with myxoid stroma: Case report of an unusual histological variant.

We describe the case of a Ewing sarcoma with prominent myxoid stroma of the temporal bone in a 26-year-old female. Histologically, the tumor exhibited a fascicular growth pattern of round to spindled cells with a minimal amount of pale eosinophilic to clear cytoplasm and oval or spindled nuclei with finely dispersed chromatin and small nucleoli. Myxoid changes were prominent (>50%), with reticular or pseudoacinar growth of the loosely cohesive cells. The tumor showed strong expression of CD99, FLI1, and CD56 and was positive for the EWSR1-FLI1 fusion transcript. The diagnosis of Ewing sarcoma with myxoid stroma (myxoid variant) is particularly problematic owing to the large number of potential mimics. The tumor extends the morphologic spectrum of Ewing sarcoma beyond the previously described histological variants, and broadens the differential diagnosis. For any round/spindle cell sarcoma, prominent myxoid stroma and CD99 immunoreactivity should prompt consideration for molecular studies that include analysis of both EWSR1 and FLI1.

Intracranial myxoid mesenchymal tumors with EWSR1-CREB family gene fusions: myxoid variant of angiomatoid fibrous histiocytoma or novel entity?

Intracranial myxoid mesenchymal tumor harboring EWSR1 fusions with CREB family of genes was recently described, and it resembles the myxoid variant of angiomatoid fibrous histiocytoma. We present three pediatric patients with intracranial EWSR1-rearranged myxoid mesenchymal neoplasm and provide a molecular genetic characterization of these tumors. Clinical histories and imaging results were reviewed. Histology, immunohistochemistry, EWSR1, FUS, NR4A3 fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS) were performed. A 12-year-old male (case 1), 14-year-old female (case 2), and 18-year-old male (case 3), presented with headaches, emesis, and seizures, respectively. The magnetic resonance images demonstrated tumors abutting the dura (cases 1 and 3) and in the third ventricle (case 2). All tumors were vascular, with solid sheets of monomorphic oval cells in a prominent myxoid/microcystic matrix. A thin fibrous pseudocapsule was present in all lesions, but definitive lymphocytic cuffing was absent. Morphologically, they closely resembled myxoid variant of angiomatoid fibrous histiocytoma. Mitoses were rare, and necrosis was absent. All tumors expressed desmin and GLUT1, and focal EMA and CD99. The proliferation index was low. FISH and NGS showed EWSR1-CREB1 fusion (cases 1 and 2), and EWSR1-CREM fusion (case 3). There were no FUS (16p11.2) or NR4A3 (9q22.33) rearrangements in case 3. Gains of 5q (including KCNIP1) and 11q (including CCND1) were present in cases 1 and 2. There were no common pathogenic genomic changes other than EWSR1 rearrangements across cases. CNS myxoid mesenchymal neoplasms with histological and immunophenotypic similarities to myxoid variant of AFH are rare, diagnostically challenging, and harbor EWSR1-CREB1 and also a novel EWSR1-CREM fusion not yet described in AFH. Therefore, it is uncertain if these tumors represent variants of AFH or a new entity. The copy number and mutational changes presented here provide support for future studies to further clarify this issue.

Myxoid adrenocortical adenoma with a pseudoglandular pattern: a case report and literature review.

Adrenocortical adenoma is a benign neoplasm derived from cells of the adrenal cortex. The myxoid variant of this tumor is extremely rare. To our knowledge, only 23 cases of myxoid adrenocortical adenoma have been reported so far and 19 of them mentioned the pseudoglandular pattern. We reported a new case of 56-year-old Chinese female patient whose left adrenal gland was shown a neoplastic lesion by computed tomography (CT) and magnetic resonance (MR) imaging. Histopathological study showed that the mass was a myxoid adrenocortical adenoma with a pseudoglandular pattern. Then, we performed immunohistochemistry with 28 biomarkers to make differential diagnosis and found that tumor cells were diffusely positive for vimentin, melan-A, CD56, NSE and USP10, and focally positive for cytokeratin pan, cytokeratin 8/18 and VEGF. The labeling index of Ki-67 and Cyclin D1 were about 1% and 50%, respectively. No immunoreactivity was found for EMA, cytokeratin 7, HMB45, S-100, alpha-inhibin, calretinin, synaptophysin, chromogranin A, P53, EGFR, MMP2, DNA topo II alpha, CA125, E-cadherin, P63, P16 and Her-2. The patient has been followed up for 37 months after tumor resection and no evidence was found to suggest any local recurrence or any metastatic disease. Myxoid adrenocortical adenoma with a pseudoglandular pattern is extremely rare. The accurate diagnosis should be based on combined consideration of clinical characteristics, CT, MR imaging and pathological features, and should be distinguished from other retroperitoneal myxoid tumors.

Primary lesser sac myxoid liposarcoma: A case report.

INTRODUCTION: Lesser sac pathological entities are uncommon. Most of these are tumors and are generally misdiagnosed as retroperitoneal lesions. CASE REPORT: A 62year old male with past history of treated hypopharyngeal cancer presented with progressive abdominal distension. Physical examination revealed a midline intra abdominal mass in the epigastrium and umbilical region. Radiological investigations were suggestive of a retroperitoneal tumor,an image guided biopsy was reported as atypical lipoma. Surgical exploration confirmed a large multi lobulated tumor arising primarily from the lesser sac, post operative histopathological examination confirmed a myxoid liposarcoma. DISCUSSION: Primary lesser sac tumors are rare, a literature review of primary lesser sac tumors with particular reference to myxoid liposarcoma is presented. CONCLUSION: Primary lesser sac liposarcomas are rare neoplasms. The myxoid variant is unique for its peculiar biological behavior, in its sensitivity to chemotherapy and radiotherapy and for the presence of specific cytogenetic marker.

Myxoid dermatofibroma on a great toe: a case report.

Dermatofibroma is a common benign fibrohistiocytic tumor with many clinicopathological variants. Myxoid dermatofibroma is one of these variants, which is characterized by marked stromal mucin deposition. This report presents a case of myxoid dermatofibroma on a great toe that had been slowly growing for two years. Histopathologically, the relatively well-circumscribed dermal tumor was separated from the epidermis by a small grenz zone. The tumor tissue consisted of oval to spindle-shaped cells with well-defined cell borders and spindly condensed nuclei. No cytologic atypia or mitotic figures were found. Although most of the tumor cells were embedded in a prominently myxoid stroma, typical features of classic dermatofibroma including a storiform growth pattern and more densely packed collagen were observed at the periphery. Immunohistochemically, the tumor cells showed positive staining for CD68 and CD99, and negative staining for CD34 and S-100. Histopathological differential diagnoses of myxoid dermatofibroma include soft tissue neoplasms with myxoid tumor stroma, such as superficial acral fibromyxoma, cellular digital fibroma, superficial angiomyxoma, myxoid dermatofibrosarcoma protuberans and low-grade fibromyxoid sarcoma. Immunohistochemical staining can be useful in the differential diagnosis of these tumors. This case highlights the challenges encountered in the histopathological interpretation of myxoid dermatofibroma. Pathologists should keep in mind the diagnosis of myxoid dermatofibroma when dealing with myxoid neoplastic lesions arising on acral sites.

A case of myxoid dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a slowly growing dermal spindle cell tumor and its myxoid variant, a rare type of DFSP, is characterized by extensive myxoid degeneration. We present the case of a 69-year-old woman with a multinodular reddish plaque on her trunk. Histopathologically, the tumor was located in the dermis and consisted of uniform spindle-shaped cells, showing strongly positive reaction for CD34, and negative for both S-100 and desmin. In addition to the typical storiform pattern, prominent myxoid stromal changes were demonstrated. Herein, we report an interesting case of myxoid DFSP, rarely reported in the dermatology literature.