Cytology of Undifferentiated Round-Cell Sarcomas of Bone and Soft Tissue: Ewing Sarcoma or Not Ewing Sarcoma , That Is the Question

<b><i>Background:</i></b> Undifferentiated round-cell sarcomas (URCSs) of soft tissue and bone are a group of clinically heterogeneous tumors. Diagnosis of these malignancies is based mainly on recurrent genetic alterations. The most common and the best known representative of this group is Ewing sarcoma (ES) which is characterized by gene fusions including EWSR1 or FUS and ETS transcription factors family. Other newly described entities are CIC-rearranged sarcoma, sarcoma with BCOR genetic alterations, and round-cell sarcoma with EWSR1-non-ETS fusions. All these novel tumors are known as Ewing-like sarcomas. <b><i>Summary:</i></b> It is believed that morphologic features of ES and Ewing-like sarcomas vary only slightly or even that cytomorphology is not relevant. But differences are usually obvious, and some cytologic findings, such as spindle cells, connective tissue fragments, or myxoid stroma, are typical for Ewing-like sarcomas but not for ES. Each of these entities is also characterized by different immunoprofiles. The aim of this review was to summarize cytomorphologic and immunohistochemical features of URCS and compare them with other small round-cell tumors. <b><i>Key Messages:</i></b> Cytology can be successfully used in URCS diagnosis as a complementary tool for core-needle biopsy or even alone in selected cases, especially in recurrent and metastatic tumors. Knowing the morphologic and immunohistochemical differences between URCS is essential to provide appropriate ancillary studies and make a definitive diagnosis.

Well-Differentiated Liposarcoma of the Hypopharynx Exhibiting Myxoid Liposarcoma-like Morphology with MDM2 and DDIT3 Co-Amplification

Well-differentiated liposarcoma (WDL) is one of the most common soft tissue sarcomas in adults. It has a predilection for middle-aged males and arises in deep-seated locations such as retroperitoneum, mediastinum, and spermatic cord. Its occurrence in young individuals at the hypopharyngeal region is an exceedingly rare event. Myxoid liposarcoma (ML)-like changes can seldom occur in some cases of WDL, which makes the diagnosis of WDL more challenging. Amplification of DDIT3 gene in a subset of cases of WDL has shown to be associated with such unique morphology. Herein, we present a case of a 36-year-old gentleman who presented with difficulty in breathing and swallowing for 3 months duration. CT scan of the neck revealed a lesion along the posterior wall of the hypopharynx measuring 3.5 cm. Histopathologic examination revealed a tumor composed of lobules of oval to spindle cells in a prominent myxoid stroma with delicate chicken-wire vasculature. In the vicinity, there were lobules composed of variably sized adipocytes separated by thick fibrous septa that contains atypical hyperchromatic spindle cells. By immunohistochemistry, the tumor cells in both components were immunoreactive for CDK4, but negative for MDM2. Fluorescence in-situ hybridization (FISH) confirmed the presence of MDM2 gene amplification. There was no evidence of FUS-DDIT3 gene rearrangement, however, DDIT3 gene was also amplified. The diagnosis of well-differentiated liposarcoma with prominent myxoid stroma was rendered. This is the first documentation of WDL with ML-like morphology harboring co-amplification of MDM2 and DDIT3 in the hypopharynx.

A case of myxofibrosarcoma located on the chest wall

Myxofibrosarcoma is a variant of fibrosarcoma, a tumor consisting of malignant fibroblasts, exhibiting a variable myxoid stroma, pleomorphism and wide curved vascular pattern. The most common location site of the tumor is the extremities. Uncommonly it is located in the trunk, head and neck. Herein we present a very rare case of surgically treated chest-wall-myxofibrosarcoma.

Vulvar Cutaneous Myxoma in a Patient With Carney Complex: Avoiding Pitfalls of Myxoid Lesions of the Vulva

We present the case of a 31-year-old woman who underwent surgical excision for a polypoid, vulvar lesion. Histopathological analysis showed a diffuse myxoid stroma admixed with scant collagen fibrils. Thin-walled and branching blood vessels were prominent, with a mild perivascular lymphocytic infiltrate. Cytologically bland spindle cells with inconspicuous nucleoli were immersed in a loose myxoid stroma. This combination of histopathological features along with multinodularity in the subcutaneous fat raised concern for deep angiomyxoma, a locally destructive neoplasm. Among our differential of myxoid lesions of the vulva, we ultimately favored the diagnosis of vulvar cutaneous myxoma. Upon further investigation, we learned that our patient was indeed known for the Carney complex. We highlight that vulvar cutaneous myxomas arising in the context of the Carney complex pose a significant diagnostic challenge for pathologists and should not be overdiagnosed as aggressive lesions such as deep angiomyxoma or other malignant stromal neoplasms.

Low-grade fibromyxoid sarcoma of the parapharyngeal space: an unusual location

Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon soft-tissue malignancy. LGFMS preferentially affects trunks and extremities of young adults; however, occasional cases have been reported in different sites of head and neck region including oral cavity, larynx and oropharynx. LGFMS usually exhibit areas of collagenised and myxoid stroma with appearance of spindle cells in whorling pattern. It is a challenge to diagnose it accurately as most of the time it is misdiagnosed as benign neoplastic entity of spindle cells. There have been only few isolated cases of LGFMS reported in head and neck region and LGFMS originating from the parapharyngeal space has never been reported before. We recently experienced a case of low grade fibomyxoid sarcoma in parapharyngeal space of neck. LGFMS have the propensity to locally recur and to metastasise. Due to its rarity in head and neck region, there are no well-established treatment and follow-up guidelines.

Superpixel Image Segmentation of the Tumoral Microenvironment in Colorectal Cancer: Frontiers Beyond the Microscope

Colorectal cancer (CRC) is the most common malignancy of the gastrointestinal (GI) tract and accounts for 9% of all cancers. The stroma and the tumoral microenvironment represent brave new frontiers for patients with colorectal cancer. Here we demonstrate novel superpixel image segmentation (SIS) techniques for whole slide images (WSI) to unravel this biology. Findings of significance include the association of low proportionated stromal area (PSA), high immature stromal percentage (ISP) and high myxoid stroma ratio (MSR) with worse prognostic outcomes in our CRC patients. Overall, stromal markers outperformed all others at predicting clinical outcomes. In particular, MSR may be able to prognosticate patients independent of tumor stage and may be the most optimal way to effectively prognosticate CRC patients which circumvents the need for more extensive deep learning (DL) based computational profiling. Approaches demonstrated here can be performed by a trained pathologist and very easily recorded during synoptic cancer reporting with appropriate quality assurance. Future well-designed, robust clinical trials will have the ultimate say in determining whether digital image analysis and superpixel image segmentation can better tailor the need for adjuvant therapy in patients with colorectal cancer.

An unusual origin of liposarcoma in an elderly man: a case report

Liposarcoma is a type of cancer with mesenchymal origin in which the bulk of tumor differentiates into adipose tissue. Liposarcoma can be found in any part of the body with fat cells, but most cases occur in the muscles of the limbs or in the retroperitoneum. Here we report a case of an elderly man with an uncommon origin of liposarcoma. A 76-year-old man presented to hospital with gastrointestinal symptoms and a palpable mass over lower abdomen. Abdominal computer tomography revealed colonic tumor with another huge intraperitoneal mass, looks like originated from mesentery of small intestine. The patient underwent an exploratory laparotomy. During operation, despite colon cancer, a 17cm mass, originated from distal ileum mesentery was noted. The specimen histopathology of the tumor resection showed well-differentiated liposarcoma with prominent myxoid stroma. Finally, the patient was discharged on the tenth postoperative day. Most of liposarcomas origin from the extremities, retroperitoneum and inguinal region. However, we have chance to find liposarcomas everywhere in our body. In our case, it was a liposarcoma derived from mesentery of small intestine and it had few reports before.