A case of primary cutaneous Ewing sarcoma in a neutropenic patient

Primary cutaneous Ewing sarcoma is a rare clinical presentation of Ewing sarcoma, usually occurring as a small, localized tumor on the extremities of young adults and associated with favorable prognosis. We report a case of primary cutaneous Ewing sarcoma, which presented on the sole of the foot of a 27‐year‐old patient with relapsed acute myeloid leukemia and neutropenia. Diagnosis was determined through histological features and staining, as well as fluorescence in situ hybridization and molecular testing. The patient underwent wide‐local excision with plan to begin targeted chemotherapy, but unfortunately died from adenovirus pneumonia while neutropenic before targeted chemotherapy was initiated.     

Superficial sarcomas with CIC rearrangement are aggressive neoplasms: A series of eight cases

CIC rearranged sarcomas have significant overlap with Ewing sarcoma, are aggressive, and typically present in deep soft tissue. They most commonly have a t(4;19)(q35;q13) with CIC-DUX4 fusion. Superficial presentation is rare. We report eight (6F, 2M; median 45-years-old, range 14-65) superficial CIC-rearranged sarcomas, involving the extremities (n = 4), vulva (n = 2), and trunk (n = 2). The tumors were composed of nodules/sheets of round cells with necrosis and hemorrhage separated by dense hyaline bands. Tumor cells had vesicular chromatin, prominent nucleoli and frequent mitotic figures. One showed pagetoid spread. Targeted next-generation sequencing was positive for CIC-DUX4 fusion (6/6); fluorescence in situ hybridization (FISH) was positive for CIC rearrangement (2/3). Eight of eight had evidence of CIC-DUX4 fusion/rearrangement by molecular techniques. Immunohistochemistry was positive for CD99+ (8/8) and DUX4+ (4/4). FISH for EWSR1 rearrangement was negative (5/5). Of five patients with at least 6 months follow-up, three of five died of disease, all within 2 years of presentation. One is alive with disease at 48 months. One is disease free at 3 months. Superficial CIC-rearranged sarcomas should be considered in cases exhibiting features reminiscent of Ewing sarcoma, but with increased pleomorphism and/or geographic necrosis. In contrast to superficial Ewing sarcomas, superficial CIC-rearranged sarcomas are aggressive.     

Expanding the differential of superficial tumors with round-cell morphology: Report of three cases of CIC-rearranged sarcoma,a potentially under-recognized entity

Among sarcomas with a round-cell morphology that lack rearrangement of the EWSR1 gene, rearrangements involving the CIC gene are the most common. In comparison with Ewing Sarcoma, CIC-rearranged sarcomas present at an older average age, arise almost exclusively in soft tissues, are clinically more aggressive, and are more likely to be resistant to the chemotherapy regimens used for Ewing sarcoma. CIC-rearranged sarcomas present more commonly in a deep location, and we suspect that superficial presentations may be under-recognized. In this case series, we report three of such cases. Overall, the morphology is similar to CIC-rearranged sarcomas of deeper locations. We hope to raise awareness among the dermatopathology community by expanding the differential of superficial tumors with round cell morphology.     

Primary superficial Ewing sarcoma: A unique entity? A case report including novel findings of ELF3 and TNFRSF14 copy number loss

Primary superficial Ewing sarcoma (psES) cases are exceedingly rare, with fewer than 150 cases reported in the literature. Small case series have suggested differences between psES and Ewing sarcoma (ES) of bone or deep soft tissues: psES appears to have a more indolent course and a higher 5-year overall survival rate. PsES is more common in older adolescent females as opposed to younger males in their peak growth velocity years in bone or deep soft tissue ES. We present a case report of a 17-year-old female with a relatively static nodule on her left thigh for 4 years. Morphologic, immunohistochemical, and molecular evaluations confirmed ES. Patient underwent a gross-total resection and a shortened course of adjuvant chemotherapy without radiation. Cancer gene panel testing found three gene abnormalities (in addition to EWSR1-FLI1 fusion): CCND1 copy number gain, ELF3 copy number loss, and TNFRSF14 copy number loss. To our knowledge, this is the first published case report of psES to include genomic sequencing and the first to report ELF3 and TNFRSF14 abnormalities in ES. Larger series of psES cases with genomic profiling are needed to elucidate a possible genetic etiology for its more indolent clinical course and favorable outcomes.     

First diagnosis of Martin‐Albright syndrome in a 58‐year‐old patient

Albright hereditary osteodystrophy (AHO), also known as Martin‐Albright syndrome (MAS), is a rare autosomal dominantly transmitted disease characterized by short stature, obesity, mental retardation, a round facies, and brachymetacarpia and ‐tarsia, as well as cutaneous calcification. The disease is caused by mutations in the GNAS gene localized on chromosome 20q13.2 encoding for an adenyl‐cyclase‐stimulating protein (Gsα). A 58‐year‐old patient presented with small stature since childhood, moderate mental retardation, round facies and soft tissue masses on the thighs. A biopsy of the latter showed subcutaneous ossification. Laboratory results showed hypocalcemia, as well as increased plasma levels of PTH and calcitonin. The clinical diagnosis was confirmed by detection of reduced activity of Gsα. In patients with cutaneous calcification and disturbed calcium metabolism, AHO is an important differential diagnostic consideration.     

Dual‐color,break‐apart fluorescence in situ hybridization probe for distinguishing clear cell sarcoma of soft tissue from malignant melanoma

Background Clear cell sarcoma (CCS) of soft tissue is a rare soft tissue sarcoma with melanocytic differentiation and shares morphologic, immunohistochemical, ultrastructural, and molecular features with malignant melanoma (MM). Because the prognosis of CCS is much different from MM, it is important to distinguish each other by selective method. CCS is well‐recognized as having the t(12;22)(q13;q12) translocation, on the other hand MM is not. Therefore, detecting Ewing sarcoma region 1 (ESWR1) gene rearrangement can serve as a crucial diagnostic determinant. Methods Biopsy was taken from a 52‐year‐old man who reported a 3‐year history of a gradually enlarging nodule on the sole of his left foot. Routine and special stains for melanocytic markers and fluorescence in situ hybridization (FISH) evaluation using dual color break‐apart rearrangement probes specific for ESWR1 was performed for formalin‐fixed tissue. Results Neoplastic cells expressed diffuse but strong positivity for HMB45 and S100 but not for Melan‐A. Dual color, break‐apart interphase FISH revealed EWS(22q12) gene rearrangements in CCS tumor cells. Conclusion Fluorescence in situ hybridization evaluation using ESWR1 gene probe for CCS sharing clinical and histopathological characteristics with MM is a valuable tool to distinguish each other.     

Low‐grade fibromyxoid sarcoma of acral sites: Case report and literature review

Low‐grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue sarcoma that usually presents as a deep‐seated tumor in young adults; however, they can occur on superficial sites, mostly documented in pediatric age groups. LGFMS presenting on acral sites is not highly emphasized in the general pathology or dermatopathology literature. The case presented is that of a 30‐year‐old man with a foot mass that was removed 15 years earlier and subsequently recurred as two masses, the first occurring between the third and fourth toes/metatarsal region and the second over the lateral tarsal region. An excisional biopsy showed a relatively circumscribed, bland spindle cell proliferation with hypocellular and hypercellular zones. The cells showed minimal pleomorphism and lacked mitotic activity. Immunohistochemical analysis showed immunoreactivity for MUC4 and break‐apart fluorescence in situ hybridization was positive for FUS rearrangement, confirming the diagnosis of LGFMS. There are multiple spindle cell tumors that occur on acral sites which usually generates a list of differential diagnoses; however, LGFMS is not usually discussed in that anatomic location. Awareness of the occurrence of LGFMS on acral sites is important to avoid misdiagnosis of this deceptively benign‐appearing tumor.     

Primary cutaneous Ewing sarcoma - Case report

Ewing sarcoma is a primitive neuroectodermal tumor rarely occurs in the skin and sobcutaneous tissues. Generally Ewing''s sarcoma is a primary bone tumor, but when present in soft tissues it characterizes an extremely uncommon clinical picture. It usually involves the deep subcutaneous tissue or muscles, and more rarely occurs like a primary skin cancer. Most patients are white, women, and in the second decade of life. The clinical features are a superficial mass, in average measuring 2-3 cm, of soft consistency, freely mobile and sometimes painful. The more affected locations are upper and lower extremities, trunk, head, neck or multiple lesions. The presence of metastases is very rare.     

Low‐grade fibromyxoid sarcoma with nuclear pleomorphism arising in the subcutis of a child

Low‐grade fibromyxoid sarcoma (LGFMS) represents a rare soft tissue tumor that was first characterized in 1987. LGFMS usually presents as a large, deeply situated mass in adults and is characterized by deceptively bland histopathologic features. LFGMS is less common in superficial soft tissue and in children. It is distinctly uncommon for LGFMS to exhibit nuclear pleomorphism. Herein, we present a case of a 10‐year‐old male who presented with a subcutaneous back mass that displayed features typical for LGFMS as well as scattered large, hyperchromatic and pleomorphic nuclei. The constellation of clinicopathologic features, including the young age of the patient, the small size and superficial location of the tumor and the presence of scattered nuclear pleomorphism are all unusual features for LGFMS. Fluorescent in situ hybridization (FISH) with a break‐apart probe for FUS revealed the presence of a FUS gene rearrangement confirming the diagnosis of LGFMS. This case highlights the importance of maintaining a high index of suspicion for LGFMS even in the context of small, superficially‐located tumors, pediatric patients or tumors with scattered nuclear pleomorphism.     

De novo myeloid sarcoma in a 4‐month‐old infant: a case report and review of the literature

Myeloid sarcoma is a rare tumor of immature myeloid cells in an extramedullary site. Myeloid sarcoma may present in a variety of locations; skin is one of the common sites. It may precede or occur concurrently with acute myeloid leukemia, chronic myeloid leukemia, other forms of myeloproliferative disorders/myelodysplastic syndrome or de novo. We report a case of a 4‐month‐old female who presented with cutaneous lesions without evidence of leukemia, determined to be de novo myeloid sarcoma. She had erythematous nodules in multiple skin sites. Biopsy revealed a diffuse atypical mononuclear cell infiltrate involving the entire dermis and extending to the subcutis. The infiltrate was diffusely positive for lysozyme, CD43, CD15, CD33, CD68 and CD117 and was negative for CD3, CD20, CD34, CD56, CD79a, CD99, myeloperoxidase, desmin, chromogranin and synaptophysin, supporting a diagnosis of myeloid sarcoma. No leukemic involvement was found on evaluation of peripheral blood or bone marrow aspiration. Chromosomal abnormalities were found at chromosomes 7, 10 and 11. The skin lesions resolved following multiple chemotherapy courses, then recurred requiring additional treatment. De novo myeloid sarcoma involving skin without evidence of leukemia can occur in an infant and may present a diagnostic challenge.     

PDGFRa amplification in multiple skin lesions of undifferentiated pleomorphic sarcoma: A clue for intimal sarcoma metastases

A 62‐year‐old human immunodeficiency virus‐positive man was admitted for multiple cutaneous and subcutaneous nodules on his lower limbs, corresponding to an undifferentiated proliferation of spindle and pleomorphic cells, with irregular nuclei and numerous mitoses. The tumor cells were negative for a large panel of immunohistochemical markers, except CD10. MDM2 immunohistochemical staining was also negative, leading to the diagnosis of Fédération Nationale des Centres de Lutte contre le Cancer grade III undifferentiated pleomorphic sarcoma (UPS). Array‐comparative genomic hybridization showed a highly complex karyotype, with amplification of the 4q12 region, an area that contains only the platelet‐derived growth factor receptor α (PDGFRa) gene. This amplification of PDFGRa, molecular hallmark of intimal sarcoma (IS), led to the diagnosis of skin IS metastasis. A positron emission tomography showed a hypermetabolic mass protruding in the preaortic area, consistent with the diagnosis of aortic IS. Our study shows that a rare differential diagnosis in peripheral UPS can be IS skin metastasis, and underlines the importance of molecular analyses in UPS.     

Histiocytic sarcoma transdifferentiated from follicular lymphoma presenting as a cutaneous tumor

Histiocytic sarcoma represents a rare and poorly understood tumor of histiocytic/dendritic cell lineage that can rarely present in the skin. Previously reported cases of histiocytic sarcoma after follicular lymphoma suggested that follicular lymphoma can transdifferentiate into histiocytic sarcoma. We describe another case involving a 40-year old male who developed histiocytic sarcoma in his right thigh 4 years after the diagnosis of grade 1 follicular lymphoma in the left neck. The two neoplasms were morphologically and immunophenotypically different but had identical immunoglobulin heavy chain gene and bcl-2 gene rearrangements, as demonstrated by polymerase chain gene reaction analysis, and the presence of t(14;18)(q32;q21) translocation was confirmed via fluorescence in situ hybridization (FISH) analysis. Because of spindle cell morphology and focal S-100 positivity, malignant peripheral nerve sheath tumor and melanoma diagnoses were made initially and extensive workup was required to discover the correct diagnosis. Lineage transdifferentiation can occur in mature lymphoid neoplasms and awareness of this phenomenon and appropriate workup is crucial for correct diagnosis, as different treatment protocols and prognosis may vary.     

Disseminated De Novo Myeloid Sarcoma in a 17‐year‐old Boy

Myeloid sarcoma (MS) is a rare extramedullary tumor of malignant myeloid cells often associated with acute myeloid leukemia. We report a case of a 17‐year‐old boy presenting with diffuse red‐brown skin nodules ultimately diagnosed with the scarcely described disseminated, de novo MS. It is important for dermatologists to keep MS on their differential when assessing patients with disseminated red‐brown nodules.     

Extra‐acral cutaneous/soft tissue sclerosing perineurioma: an under‐recognized entity in the differential of CD34‐positive cutaneous neoplasms

Background: Perineuriomas are an uncommon group of tumors composed of perineurial cells of peripheral nerve sheath lineage. Variants include soft tissue (extraneural), intraneural, sclerosing, reticular and plexiform forms. Sclerosing perineuriomas have been reported to occur almost exclusively on the hands of young men. Herein, we report three extra‐acral cutaneous/soft tissue perineuriomas that show significant associated sclerosis. Methods: Skin biopsy specimens from three patients were evaluated for cytomorphology and degree of associated sclerosis, which was classified as either focal or diffuse. Immunohistochemical expression of epithelial membrane antigen (EMA), CD34 and S‐100 was also assessed to facilitate further classification. Results: Histopathologically, the tumors showed both focal and diffuse sclerosis, and lesional cells were generally spindled in shape. Immunohistochemical staining showed diffuse positivity for CD34 and focal or diffuse positivity for EMA. The cells uniformly lacked expression of S‐100 protein. Conclusions: Sclerosing perineuriomas can occur in extra‐acral locations and should be considered in the differential of EMA‐positive cutaneous spindle‐cell proliferations. It is also important to recognize that perineuriomas can express CD34 and should be considered in the differential diagnosis of CD34‐positive cutaneous neoplasms. Fox M, Gleason BC, Thomas AB, Victor TA, Cibull TC. Extra‐acral cutaneous/soft tissue sclerosing perineurioma: an under‐recognized entity in the differential of CD34‐positive cutaneous neoplasms.     

Epithelioid sarcoma on the foot masquerading as an intractable wound for > 18 years

Slow‐growing sarcomas may give rise to intractable wounds, which may be attributed to commoner causes. A 57‐year‐old man with diabetes mellitus presented with a 24‐year history of a chronic wound that originated on his left great toe. Because of the long history, the nonspecific histological findings and the complication of ulcerative colitis, we misdiagnosed his ulcer as pyoderma gangrenosum. The wound was eventually diagnosed correctly by histological examination of a skin biopsy and the use of immunohistochemistry to detect cytokeratin, epithelial membrane antigen and vimentin. Specimens obtained 16 years earlier showed the same staining pattern. Radiological examinations revealed no metastasis. The patient received a below‐knee amputation without further chemotherapy or radiotherapy. When patients have intractable ulcers, appropriate biopsies and immunohistochemical examinations are sometimes necessary to exclude a malignancy even if the history and symptoms do not suggest a diagnosis of sarcoma.     

A 10‐year analysis of cutaneous mesenchymal tumors (sarcomas and related entities) in a skin cancer center

Background Mesenchymal neoplasms (sarcomas) of skin are rare. Patients with sarcomas were analyzed over the last decade. Methods Over a 10‐year period, we conducted a retrospective analysis of patients diagnosed and treated in an urban academic teaching hospital in Saxony, Germany. Clinical and pathologic files were used. Results We identified 65 adult patients with 67 primary cutaneous sarcomas. The mean age was 73.1 (±15.5) years with a male predominance (78.5%). None of the sarcomas was detected by a skin cancer screening program. The diagnosis was atypical fibroxanthoma (n = 41 patients with 43 tumors), cutaneous angiosarcoma (eight), dermatofibrosarcoma protuberans (two), nodular epithelioid cell sarcoma (one), Kaposi sarcoma (three), leiomyosarcoma (five), malignant fibrous histiocytoma (two), fibromyxoid sarcoma (one), and cutaneous angiomyxoma (two). The preferred tumor localization was the head and neck area (44 patients). Follow‐up was 0.5–5.5 years (mean 18 ± 12 months). We observed metastatic spread of atypical fibroxanthoma in 12.5%, demonstrating that this type of sarcoma can run an aggressive course. Mohs surgery is still the cornerstone of treatment, although new options in palliative or adjuvant treatment are available. Conclusions Mesenchymal neoplasms (sarcomas) are an important group of cutaneous malignancies. Awareness needs to be improved.     

Case report of cutaneous histiocytic sarcoma: diagnostic and therapeutic dilemmas

Histiocytic sarcoma is a rare hematologic malignant neoplasia originating from histiocytic or dendritic cell clones. The lesions may be in nodal or extranodal sites, most commonly in the gastrointestinal tract. A small number of cases presents as unique cutaneous lesions. The definitive diagnosis is made by positivity for the immunohistochemical markers CD163, CD68, CD4 and lysozyme. The treatment is controversial, often with combined systemic chemotherapy. This is a case of cutaneous histiocytic sarcoma in an 82-year-old patient presenting two nodular lesions in the breast and right arm which were treated with simple excision and multidisciplinary follow-up, avoiding aggressive management and exhaustive investigations. Although most studies report aggressive evolution, the patient had good and stable clinical status during the twelve-month follow-up period.