Malignant melanoma is genetically distinct from clear cell sarcoma of tendons and aponeurosis (malignant melanoma of soft parts)

Back to the future! Selected bone and soft tissue neoplasms with shared genetic alterations but differing morphological and immunohistochemical phenotypes

Bone and soft tissue tumors (BST) are a highly heterogeneous group largely classified by their line of differentiation, based on their resemblance to their normal counterpart in adult tissue. Yet, rendering a specific diagnosis can be challenging, primarily due to their rarity and overlapping histopathologic features or clinical presentations. Over the past few decades, seemingly histogenetic-specific gene fusions/translocations and amplifications have been discovered, aiding in a more nuanced classification, leading to well-established objective diagnostic criteria and the development of specific surrogate ancillary tests targeting these genetic aberrations (e.g., immunohistochemistry). Ironically, the same research also has revealed that some specific tumor subtypes may be the result of differing and often multiple gene fusions/translocations, but, more interestingly, identical gene fusions may be present in more than one phenotypically and biologically distinct neoplasm, sometimes with entirely different clinical behavior. Prime examples include, EWSR1::ATF1 and, less commonly, EWSR1::CREB1 gene fusions present in both clear cell sarcoma, a malignant high-grade tumor with melanocytic differentiation, and angiomatoid fibrous histiocytoma, a mesenchymal neoplasm of intermediate malignancy with a generally indolent course. Similarly, MDM2 amplification, once deemed to be pathognomonic for atypical lipomatous tumor/well differentiated and dedifferentiated liposarcoma, has been documented in a range of additional distinct tumors, including low grade osteosarcomas (e.g. low grade central and surface parosteal) and high-grade intimal sarcomas, amongst others. Such findings reinforce the importance of careful attention to morphological and clinicoradiological features and correlation with molecular testing before rendering a specific diagnosis. Future classification systems in BST neoplasms cannot be solely based on molecular events and ideally will balance morphologic features with molecular analysis. Herein, we provide a narrative literature review of the more common BST neoplasms with shared genetic events but differing demographics, morphology, immunophenotype, and clinical behavior, re-emphasizing the importance of the hematoxylin and eosin slide and the "eye" of the practicing pathologist.

A Rare Case of Clear Cell Sarcoma of the Tongue: A Case Report

Clear cell sarcoma (CCS), previously known as soft tissue melanoma due to similarities with melanoma, is a rare and aggressive neoplasm. This tumor predominantly occurs in the lower limbs and rarely affects the tongue, as well as other head and neck locations. To our knowledge, only five cases have been reported in the English literature. CCS presents many similar morphological and immunohistochemical features to those of melanomas, sarcomatoid cell carcinoma, angiomatoid histiocytoma, and Ewing sarcoma, which makes the diagnosis difficult, especially in cases of uncommon locations. The treatment is based on oncological surgery and adjuvant radiation therapy as these tumors show low sensitivity to chemotherapy. This study aimed to report a case of an 88-year-old male patient who presented a large, rapidly growing nodular lesion on the right border of the mobile tongue diagnosed with CCS of the tongue.

Clear cell sarcoma of soft tissue with plasmacytoid morphology: A rare case report

RATIONALE

Clear cell sarcoma of soft tissue (CCSST) is a rare malignant tumor that occurs in the extremities of young adults. CCSST has been documented to have atypical histopathological features, such as epidermotropism or myxoid differentiation, which may set pitfalls in the differential diagnosis. We report a case of CCSST with plasmacytoid morphology which has never been described.

PATIENT CONCERNS

A 15-year-old male, presented with a 5-cm mass in his left inguinal area.

DIAGNOSIS

Positron emission tomography-computed tomography examination showed nodules in the left groin and the lung, the latter was considered metastasis. A core needle biopsy with the diagnosis of CCSST with plasmacytoid morphology was made according to histology, immunostaining, and molecular analysis.

INTERVENTIONS

The patient received chemotherapy of doxorubicin and ifosfamide.

OUTCOMES

The patient failed to respond to the standard chemotherapy and deceased twelve months after diagnosis.

LESSONS

This special case of CCSST with plasmacytoid features demonstrated a morphological variation never been documented and may easily lead to misdiagnosis. For such cases, molecular analysis is essential to provide solid evidence for accurate diagnosis.

Protein arginine methyltransferase 5 is essential for oncogene product EWSR1-ATF1-mediated gene transcription in clear cell sarcoma

Transcription dysregulation is common in sarcomas driven by oncogenic transcription factors. Clear cell sarcoma of soft tissue (CCSST) is a rare sarcoma with poor prognosis presently with no therapy. It is characterized by a balanced t(12;22) (q13;q12) chromosomal translocation, resulting in a fusion of the Ewing's sarcoma gene EWSR1 with activating transcription factor 1 (ATF1) to give an oncogene EWSR1-ATF1. Unlike normal ATF1, whose transcription activity is dependent on phosphorylation, EWSR1-ATF1 is constitutively active to drive ATF1-dependent gene transcription to cause tumorigenesis. No EWSR1-ATF1-targeted therapies have been identified due to the challenges in targeting intracellular transcription factors. Through proteomics screening to identify potential druggable targets for CCSST, we discovered protein arginine methyltransferase 5 (PRMT5) as a novel protein to interact with EWSR1-ATF1. PRMT5 is a type II protein arginine methyltransferase to symmetrically dimethylate arginine residues in substrate proteins to regulate a diverse range of activities including gene transcription, RNA splicing, and DNA repair. We found that PRMT5 enhances EWSR1-ATF1-mediated gene transcription to sustain CCSST cell proliferation. Genetic silencing of PRMT5 in CCSST cells resulted in severely impaired cell proliferation and EWSR1-ATF1-driven transcription. Furthermore, we demonstrate that the clinical-stage PRMT5 inhibitor JNJ-64619178 potently and efficaciously inhibited CCSST cell growth in vitro and in vivo. These results provide new insights into PRMT5 as a transcription regulator and warrant JNJ-64619178 for further clinical development to treat CCSST patients.

Case report: Robust response of metastatic clear cell sarcoma treated with cabozantinib and immunotherapy

Clear Cell Sarcoma (CCS), also referred to as malignant melanoma of soft parts, is a rare and aggressive malignant tumor. It comprises 1% of all soft tissue sarcomas and is known to be radio- and chemotherapy resistant. CCS shares morphological and immunohistochemical features with malignant melanoma, including melanin biosynthesis and melanocytic markers. However, it is distinct for the presence of EWSR1-ATF1 translocation which activates MITF transcription factor. We report here of an aggressive case of CCS in a 9-year-old patient, which demonstrates the critical role of molecular analysis in the diagnosis and treatment of uncommon cancer variants in the era of personalized medicine. The EWSR1-ATF1 translocation induces pathological c-Met activation, and so, following unsuccessful CTLA4 and PD-1 blockade immunotherapy, the child received cabozantinib, a small molecule tyrosine kinase inhibitor, with the intent to block c-Met oncogenic effect. In parallel, active immunization, using hapten di-nitrophenyl modified autologous tumor cells was administered with monotherapy PD-1 inhibitor nivolumab. Under this "triplet" therapy, the patient attained an initial partial response and was progression-free for 2 years, in good performance status and resumed schooling. Based on our observation, cabozantinib can be used as an effective and potentially life-prolonging treatment in CCS. We suggest that priming the child's immune system using her autologous tumor and combating T cell exhaustion with PD-1 blockade may have synergized with the targeted therapy. Combining targeted and immunotherapy is a rapidly growing practice in solid tumors and provides a glimpse of hope in situations that previously lacked any treatment option.

[Soft tissue clear cell sarcoma. A report of three cases]

The paper describes three cases of soft tissue clear cell sarcoma, a rare melanin-producing malignant tumor, which is diagnosed in 52-to-87-year-old women. It provides a clinical and morphological description of the tumor and the results of immunohistochemical tests.

Diagnostic Utility of a Custom 34-Gene Anchored Multiplex PCR-Based Next-Generation Sequencing Fusion Panel for the Diagnosis of Bone and Soft Tissue Neoplasms With Identification of Novel USP6 Fusion Partners in Aneurysmal Bone Cysts

CONTEXT.—

Bone and soft tissue tumors are heterogeneous, diagnostically challenging, and often defined by gene fusions.

OBJECTIVE.—

To present our experience using a custom 34-gene targeted sequencing fusion panel.

DESIGN.—

Total nucleic acid extracted from formalin-fixed, paraffin-embedded (FFPE) tumor specimens was subjected to open-ended, nested anchored multiplex polymerase chain reaction and enrichment of 34 gene targets, thus enabling detection of known and novel fusion partners.

RESULTS.—

During a 12-month period, 147 patients were tested as part of routine clinical care. Tumor percentage ranged from 10% to 100% and turnaround time ranged from 3 to 15 (median, 7.9) days. The most common diagnostic groups were small round blue cell tumors, tumors of uncertain differentiation, fibroblastic/myofibroblastic tumors, and adipocytic tumors. In-frame fusion transcripts were identified in 64 of 142 cases sequenced (45%): in 62 cases, the detection of a disease-defining fusion confirmed the morphologic impression; in 2 cases, a germline TFG-GPR128 polymorphic fusion variant was detected. Several genes in the panel partnered with multiple fusion partners specific for different diagnoses, for example, EWSR1, NR4A3, FUS, NCOA2, and TFE3. Interesting examples are presented to highlight how fusion detection or lack thereof was instrumental in establishing accurate diagnoses. Novel fusion partners were detected for 2 cases of solid aneurysmal bone cysts (PTBP1-USP6, SLC38A2-USP6).

CONCLUSIONS.—

Multiplex detection of fusions in total nucleic acid purified from FFPE specimens facilitates diagnosis of bone and soft tissue tumors. This technology is particularly useful for morphologically challenging entities and in the absence of prior knowledge of fusion partners, and has the potential to discover novel fusion partners.

Orthopaedic Manifestations of Melanoma and Their Management

Melanoma is an aggressive form of skin cancer associated with significant morbidity and mortality. Although commonly seen in dermatologist clinics, orthopaedic surgeons must be aware of these lesions in various ways. The five common musculoskeletal manifestations of melanoma will be discussed as well as the epidemiology, pathogenesis, diagnosis, staging, treatment, and prognosis of melanoma. With an index of suspicion and awareness of melanoma, a thorough history and detailed physical examination are critical in establishing a diagnosis. An adequately performed biopsy will confirm the diagnosis and assist in determining prognosis. As ambassadors of health for the musculoskeletal system, orthopaedic surgeons may be the first practitioners to encounter a pigmented skin lesion. Acral pigmented lesions should prompt a concern for melanoma with appropriate subsequent steps for management to follow. Finally, it is important for every orthopaedic surgeon to consider disseminated melanoma in the differential diagnosis of a skeletal metastasis, a deep soft-tissue mass, or lymphadenopathy in a patient with a previous history of a melanotic lesion.

Primary Cutaneous Clear Cell Sarcoma, Clinical Outcome With Sentinel Lymph Nodes Status

OBJECTIVES

Primary cutaneous clear cell sarcoma (PCS) is a rare malignancy and difficult to differentiate from melanoma. We investigated factors influencing survival and recurrence.

METHODS

An institutional cancer registry and literature search were used for a retrospective study. Only clear cell sarcoma cases with a primary site of skin and subcutaneous tissue were included. Kaplan-Meier and Cox regression analyses were used to assess survival time and hazard ratios.

RESULTS

Three eligible cases were identified at our institution. In addition, the PubMed and Google Scholar reviews identified 1,878 items, with 23 patients with PCS. The median age was 25 years with 62% female. The tumors ranged in size from 0.4 to 4.5 cm. Cytogenetics showed t(12;22)(q13;q12) in all cases and a unique variant of t(2;22)(q32.3;q12) in one case. Surgery was the most common treatment, followed by chemotherapy/radiation. PCS recurred in 46% of patients with a median relapse-free survival time of 15 months. Only two known PCS-related mortalities were recorded, at 38 and 60 months following initial diagnosis. Smaller tumor size and negative sentinel lymph node biopsy (SLNB) status were significantly associated with a better disease-free survival.

CONCLUSIONS

Tumor size and SLNB status influence PCS survival and recurrence. More research is needed due to the rarity of this disease.

A rare case of primary dermal clear cell sarcoma with focal epidermotropism: An entity difficult to distinguish from melanoma

Clear cell sarcoma (CCS) is an uncommon soft-tissue sarcoma that only rarely arises within the dermis. It is challenging to distinguish dermal CCS from nodular, primary dermal, or metastatic melanoma, as they share morphologic features and immunoprofiles. We describe a dermal CCS in a 25-year-old man with a cutaneous groin mass. The lesion was initially diagnosed as melanoma, likely metastatic. On consultation, in addition to a melanoma-like tumor in the dermis, we identified focal infiltration of tumor cells into the overlying epidermis (epidermotropism), resembling primary nodular or metastatic melanoma. Given the patient's age and absence of a history of primary melanoma, fluorescence in situ hybridization (FISH) was performed, which revealed separation of the 5' and 3' EWSR1 probe signals on chromosome 22q12, prompting a diagnosis of CCS. Our case highlights the histopathological, immunohistochemical, and ultrastructural similarities between CCS and melanoma, and the consequent potential for major diagnostic confusion. In such cases, FISH analysis remains the key to diagnosis. CCS should be considered in patients with a melanoma-like tumor in the dermis or subcutaneous tissue without epidermal (or with minimal) involvement, or prior to diagnosing metastatic melanoma in the absence of a known history of primary melanoma, especially in young individuals.

Clear cell sarcoma in unusual sites mimicking metastatic melanoma

BACKGROUND

Clear cell sarcoma is an aggressive rare malignant neoplasm with morphologic and immunohistochemical similarities to malignant melanoma. Both disease entities display melanin pigment and melanocytic markers, making differentiation between the two difficult. Although clear cell sarcoma cases in the literature have mainly involved deep soft tissues of the extremities, trunk or limb girdles, we report here two cases of primary clear cell sarcoma in unusual sites and describe their clinicopathologic findings.

CASE SUMMARY

The first case involves a 37-year-old female, who presented with jaw pain and a submandibular mass. The second case involves a 33-year-old male, who presented with back pain and a thoracic spine tumor. Both cases showed tumors with diffuse infiltration of neoplastic cells that were positive for melanocytic markers, and in both cases this finding led to an initial diagnosis of metastatic melanoma. However, further analysis by fluorescence in situ hybridization (commonly known as FISH) showed a rearrangement of the EWS RNA binding protein 1 (EWSR1) gene on chromosome 22q12 in both patients, confirming the diagnosis of clear cell sarcoma.

CONCLUSION

Distinction between clear cell sarcoma and malignant melanoma can be made by FISH, particularly in cases of unusual tumor sites.

Primary clear cell sarcoma of the tongue and surgical reconstruction: About a rare case report

Clear cell sarcomas (SCC), also called "soft-tissue melanoma", are rare and aggressive tumors that preferentially affect the lower limbs (tendons and fasciae) and which have also been described in head and neck localizations. Their clinical and immunohistochemical mimicry with melanoma makes it difficult to diagnose sarcomas. SCC treatment is mainly focused on large-scale resection surgery with adjuvant radiotherapy because of their low chemo-sensitivity and extreme lymphophilia. In case of head and neck localization, these treatments may lead to function and aesthetic sequelae thus requiring the use of modern techniques of reconstructive surgery. The authors describe the diagnosis, treatment and follow-up of large lingual SCC case using a DIEP free flap reconstruction according to an original technique developed in the department. Given the characteristics of patients with SCC (a high proportion of women between 20 and 40 years old) and its inherent qualities (low morbidity of the donor site, volume delivered and excellent plasticity), the fascio-cutaneous free flap type "DIEP" "taken according to the design of the" Cathedral triptych seems to be a viable choice among the range of reconstruction solutions.

Significance of MRI in the diagnosis and differentiation of clear cell sarcoma of tendon and aponeurosis (CCSTA): A case report

RATIONALE

Clear cell sarcoma of tendon and aponeurosis (CCSTA) or soft parts is a rare malignant melanin producing tumor entity that is derived from the neural crest cells originating from soft tissues displaying melanocytic differentiation. Diagnosis of CCSTA is difficult as it is dependent on age, size, location, necrosis, calcifications, cystic degeneration, and local to distant metastatic deposits. These tumors have very poor prognosis with a survival rate of 5-10 years because of local recurrence, early to late metastasis to lymph nodes, lungs, bones, and liver.

PATIENT CONCERNS

A 30-year-old Asian male has presented with a painful mass in the posterior aspect of the right ankle. He recalled of noticing an increase in the size of the lump after a traumatic insult 3 months ago. Physical examination revealed a mass of size 9x4 cm in the posterior ankle with no cutaneous ulcerative lesions. There is no history of any longstanding illness or malignancy.

DIAGNOSES

Clear cell Sarcoma of Tendon and Aponeurosis (CCSTA) or CCS of Soft parts.

INTERVENTIONS

Conventional radiography demonstrated merely a soft tissue mass in the posterior compartment of the right ankle and significant calcaneal bone erosion with the sparse trabecular pattern. Plain conventional tomography showed a well-defined soft tissue heterogeneous mass with a hypoattenuating osteo-destructive focal lesion in the calcaneus. Magnetic resonance imaging (MRI) - T1 weighted imaging (T1WI) revealed an iso-intense signal relative to adjacent muscle; heterogeneous high-signal intensity on fat saturated T2 weighted imaging (T2WI). On contrast examination, lesion on T1WI, showed a heterogeneous high signal intensity, central low signal intensity with peripheral and septal enhancement. The immune-histochemistry analysis was positive for HMB-45, S-100, myoD1 and Ki67 (30%). Correlating with imaging and immune-histochemistry, a confirmatory diagnosis of CCSTA was made.

OUTCOMES

CCSTA is typically a slowly growing painless mass in the deep soft tissues of ear, pancreas, kidney, penis, abdomen, especially in the lower extremities- Achilles tendon and aponeurosis of the ankle or in foot of young adults. As, these tumors are highly malignant, difficult to diagnose, early recognition by imaging and surgical excision are the mainstay of management.

LESSONS

Our case emphasizes the importance of recognizing radiological characteristics of CCSTA, and its differentiation from other soft tissue tumors, when presenting atypically. MRI plays a significant role in the diagnosis supported by histopathology and immune-histochemistry. So, radiologists should be familiar about this presentation that could guide other personnel for early detection of soft tissue tumors while including CCSTA into differential diagnosis for evaluation.

[Soft tissue melanoma: a clinical case]

Le mélanome des tissus mous a été décrit en 1965 par Enzinger sous le nom de sarcome à cellules claires. En 1983, Chung et Enzinger le rebaptisent mélanome des parties molles en raison de similitudes immunohistochimiques avec le mélanome. Nous rapportons un cas de cette forme rare de mélanome, chez un jeune homme de 22 ans qui avait une lésion molluscoïde de la cheville sans signes cliniques de malignité, et dont l’examen histologique a permis de retenir ce diagnostic.

Primary Clear Cell Sarcoma of the Dermis Mimicking Malignant Melanoma

Background:

Clear cell sarcoma is a rare malignant soft tissue neoplasm that typically involves tendons and aponeurosis. Clear cell sarcoma in the dermis is an extremely rare occurrence, and it is difficult to differentiate between this neoplasm and dermal malignant melanoma because they have similar morphologic and immunohistochemical features. Although rare, clear cell sarcoma of the skin typically occurs in the extremities. To our knowledge, there are no reported cases of primary clear cell sarcoma of the skin occurring in the neck. Here, we report an unusual case of clear cell sarcoma arising in the skin of the neck.

Case Report:

A 43-year-old female presented with a right neck lesion. Histologic sections of the lesion showed a nodular proliferation of spindle cells with pale cytoplasm with epithelioid features involving the entire dermis with no epidermal component. The tumour cells were positive for melanocytic markers, including S100 and Human Melanoma Black 45, which led to an initial diagnosis of malignant melanoma. Fluorescence in situ hybridization showed a rearrangement of the EWSR1 gene on chromosome 22q12, which led to a diagnosis of primary clear cell sarcoma in the skin.

Conclusion:

Because the treatments for clear cell sarcoma and conventional melanoma are different, fluorescence in situ hybridization for EWSR1 should be performed in any dermal lesions with melanocytic features that do not have an in situ component.

Multiple clear-cell sarcomas of small intestine with parotid gland metastasis: A case report

Clear-cell sarcoma is a rare, malignant soft tissue tumor that displays melanocytic differentiation with a distinct molecular profile. It is rarely localized in the gastrointestinal tract. Herein we reported a case of multiple synchronous clear-cell sarcomas of the gastrointestinal tract with parotid gland metastasis. A 51-year-old male patient presented with a growing painless mass under the right ear. A preoperative positron emission tomography/computed tomography showed multiple intestinal masses and a mass in the right parotid with increased glucose uptake, and he underwent operative treatment with resection of three tumors in the jejunum and ileum and then received a right parotidectomy. Postoperative pathological examination showed that cells in the intestinal tumor were consistent with clear-cell sarcoma of the gastrointestinal tract, and the malignant cells in the parotid gland were similar to the intestinal tumor. Immunohistochemical studies revealed positive expression of HMB-45, Melan-A, and S-100. EWSR1 gene fusion transcripts were undetectable by fluorescence in situ hybridization.

Simultaneous Clear Cell Sarcomas of the Duodenum and Jejunum

Clear cell sarcoma (CCS) is an uncommon tumor that usually presents as an extremity mass but can rarely manifest as a gastrointestinal tumor with a diverse spectrum of symptoms, most commonly related to a mass effect or ulceration. Herein we report a case in which two separate tumors, one in the duodenum and the other in the jejunum, present concurrently. The subject presented with symptomatic anemia and underwent imaging and endoscopic studies that culminated in the discovery of the two lesions. He subsequently underwent operative treatment with resection of both tumors and made an unremarkable recovery. The resection specimen consisted of two separate clear cell sarcomas with negative margins. Under microscopic evaluation, they demonstrated nested growths of epithelioid cells with scattered spindled cells infiltrating the enteric wall. The neoplastic cells were positive for S100 with scattered expression of Melan A. Florescence in situ hybridization revealed a translocation at the EWRS1 locus. He was disease-free for 30 months following the procedure; then he developed a rapidly progressing metastatic disease with subsequent death 4 months later.

Mucosal melanoma: correlation of clinicopathologic, prognostic, and molecular features

Although the presence of the t(12;22)(q13;q12) translocation (the defining molecular feature of malignant melanoma of soft parts/clear cell sarcoma) in cutaneous melanoma has been investigated, no large-scale studies have been performed among mucosal melanoma (MucM). In this study we assessed the prevalence of the EWSR1 rearrangement in primary MucM, and analyzed gross and microscopic features with their potential impact on diagnosis and prognosis. Overall, 132 specimens from 84 patients were included. A total of 55 cases had an intramucosal component. Survival of MucMs of the head and neck was associated with two independent factors: size and histology. Tumors more than 3 cm in greatest dimension had an average survival of 12.75 months; those 3 cm or less had an average survival of 38.3 months (P=0.035). Purely epithelioid tumors had an average worse survival of 16.8 months (P=0.028). A cut-off value of 1 mm for Breslow depth provided a statistically significant difference in survival at both 3 and 5 years (P=-0.02) by multivariate analysis in the gynecologic tract. At the molecular level three cases had a EWSR1 rearrangement by fluorescent in-situ hybridization, but only one with an intramucosal component. None of the 58 cases tested by PCR showed the presence of the EWSR1 rearrangement. With the exception of vulvar melanomas, the prognosis of mucosal-associated melanomas was poor and there was a suggestion that spindle morphology may be more favorable. Our study also showed that the EWSR1 rearrangement was very uncommon among MucM. Though 'clear cell sarcoma' is embedded in the sarcoma literature, the synonym 'melanoma of soft parts' has considerable justification in light of our evolving understanding of the molecular genetics in the family of malignant melanomas.

Malignant melanoma of soft parts with osteoclast-rich giant cells: A rare tumour of the jejunum

Malignant melanoma of soft parts (MMSP), first described by Franz M. Enzinger, is a rare tumour of unknown cell origin. We describe a case of a 45-year-old male who presented with a one-year history of abdominal pain, weakness, and anaemia. Computerised tomography enteroclysis showed a mass in the jejunum that was suggestive of a gastrointestinal stromal tumour. An ulceroinfiltrative lesion measuring 6.5 x 4 x 2cm was identified. Microscopy revealed typical features of MMSP with numerous osteoclasts-like giant cells. The diverse histomorphology and immunohistochemical characteristics of this case involving a rare tumour at a rare site is presented.

Chromosomal copy number analysis in melanoma diagnostics

The majority of melanocytic neoplasms can be correctly diagnosed using routine histopathologic analysis. However, a significant minority of tumors have ambiguous histopathologic attributes that overlap between melanocytic nevi and melanoma. Ancillary tests that assist in distinguishing potentially lethal melanomas from benign melanocytic nevi with atypical histopathologic features are available, but still need refining.Most melanomas have chromosomal copy number aberrations, frequently involving multiple chromosomes. With rare exceptions, such anomalies are not found in melanocytic nevi. This difference formed the basis to develop assays that can help distinguish melanoma from nevi by fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH). FISH can detect chromosomal copy number changes of a limited number of loci within individual cells. By contrast, CGH assesses copy number across the entire genome, but typically is performed on bulk cell populations so that copy number changes in individual cells or subpopulations of cells can go undetected. Both FISH and CGH have been used to provide genomic information in histopathologically ambiguous melanocytic tumors that can assist pathologists make correct diagnoses.

Non-antiepileptic drugs for trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia was defined by the International Association for the Study of Pain as a sudden, usually unilateral, severe, brief, stabbing recurrent pain in the distribution of one or more branches of the fifth cranial nerve. Standard treatment is with anti-epileptic drugs. Non-antiepileptic drugs have been used in the management of trigeminal neuralgia since the 1970s. This is an update of a review first published in 2006 and previously updated in 2011.

OBJECTIVES

To systematically review the efficacy and tolerability of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH METHODS

On 20 May 2013, for this updated review, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2013, Issue 4), MEDLINE (January 1966 to May 2013), EMBASE (January 1980 to May 2013), LILACS (January 1982 to May 2013) and the Chinese Biomedical Retrieval System (1978 to May 2013). We searched clinical trials registries for ongoing trials.

SELECTION CRITERIA

We included double-blind, randomised controlled trials in which the active drug was used either alone or in combination with other non-antiepileptic drugs for at least two weeks.

DATA COLLECTION AND ANALYSIS

Two authors decided which trials fitted the inclusion criteria and independently graded risk of bias. We assessed the quality of the evidence according to the GRADE criteria for this update.

MAIN RESULTS

In this 2013 update, we updated the searches, but identified only two new ongoing studies. The review includes four trials involving 139 participants. The primary outcome measure in each was pain relief. Three trials compared one of the oral non-antiepileptic drugs tizanidine, tocainide or pimozide with carbamazepine. The quality of evidence for all outcomes for which data were available was low. In a trial of tizanidine involving 12 participants (one dropped out due to unrelated disease), one of five participants treated with tizanidine and four of six treated with carbamazepine improved (risk ratio (RR) 0.30, 95% confidence interval (CI) 0.05 to 1.89). Few side effects were noted with tizanidine. For pimozide, there was evidence of greater efficacy than carbamazepine at six weeks. Up to 83% of participants reported adverse effects but these did not lead to withdrawal; the report did not provide comparable data for carbamazepine. Limited data meant that we could not assess the effects of tocainide; however, data from non-randomised studies (not included in this review) indicate that serious haematological adverse events can occur. A trial involving 47 participants compared 0.5% proparacaine hydrochloride eyedrops with placebo but did not show any significant benefits, again according to low-quality evidence. The report did not mention adverse events. The proparacaine trial was at low risk of bias; the other trials were at unclear risk of bias overall.

AUTHORS' CONCLUSIONS

There is low-quality evidence that the effect of tizanidine is not significantly different than that of carbamazepine in treating trigeminal neuralgia. Pimozide is more effective than carbamazepine, although the evidence is of low quality and the data did not allow comparison of adverse event rates. There is also low-quality evidence that 0.5% proparacaine hydrochloride eye drops have no benefit over placebo. Limitations in the data for tocainide prevent any conclusions being drawn. There is insufficient evidence from randomised controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.

Primary Clear Cell Sarcoma of the Tongue

Clear cell sarcoma shares features with melanoma, but frequently shows EWSR1 rearrangements. It is an aggressive tumor typically occurring in the soft tissues of the extremities, with a gastrointestinal variant with less consistent melanocytic differentiation. It is extremely rare in the head and neck region, with no reported cases in the oral cavity. We report a case of an 82-year-old woman with a clear cell sarcoma arising in the tongue, with cervical lymph node metastases. Histologically, the tumor showed some features of gastrointestinal clear cell sarcoma. No osteoclast-type giant cells were present. The tumor cells were positive for S100 protein and negative for other melanocytic markers. Fluorescence in situ hybridization showed rearrangements of EWSR1 and ATF1. This case expands the spectrum of clear cell sarcoma with a gastrointestinal-like variant in a novel site, emphasizing the need to consider it as a differential diagnosis to melanoma in mucosal sites.

Clinicopathological features, diagnosis and treatment of clear cell sarcoma/melanoma of soft parts

Clear cell sarcoma of tendons and aponeuroses is a rare, high grade malignant soft tissue tumor resembling melanoma and soft tissue sarcomas. Clinical and Imaging Presentation: The median age at presentation is 27 years and the most common location are the foot and the ankle. MR imaging typically shows a benign looking, well defined, homogenous mass; on T1-weighted MR images, it is usually homogeneous and isointense or slight hyperintense to muscle, whereas on T2-weighted MR images, it is usually more heterogeneous with variable signal intensity. Pathology: Microscopically, the clear cell appearance is due to the accumulation of glycogen. The cells show no or minimal pleomorphism, and paucity of mitotic figures that is in concordance with the slow-growing behavior of the tumor. Scattered multinucleated giant cells are commonly present; areas of necrosis and melanin pigment may be identified. The reciprocal translocation t(12;22)(q13;q12) is observed in more than 90% of clear cell sarcoma cases. In addition, polysomy of chromosome 8 has been observed as a secondary abnormality in many cases of clear cell sarcoma. The differential diagnosis of clear cell sarcoma should include melanoma, epithelioid malignant peripheral nerve sheath tumor, melanotic schwannoma, paraganglioma-like dermal melanocytic tumor, perivascular epithelioid cell neoplasms (PEComas), cellular blue naevus, synovial sarcoma (monophasic type), alveolar soft part sarcoma, paraganglioma, epithelioid sarcoma and carcinomas. Treatment and Prognosis: The treatment of choice for clear cell sarcoma is wide surgical resection. If complete excision is achieved, adjuvant treatments are not unnecessary. Chemotherapy is predominantly employed in patients with metastatic disease. The 5 to 20 year survival of the patients with clear cell sarcoma range from 67% to 10%. The rates of local recurrence ranges up to 84%, late metastases up to 63%, and metastases at presentation up to 30%.

Molecular diagnostics complementing morphology in superficial mesenchymal tumors

Molecular techniques are increasingly important in the practice of surgical pathology. In soft tissue tumors, there are a number of tumors with recurring cytogenetic abnormalities. Knowledge of these abnormalities has furthered our understanding of these tumors and has also allowed development of molecular techniques to aid in the diagnosis. This review will focus on mesenchymal tumors with specific cytogenetic abnormalities that may present as a superficial tumor of the dermis or subcutis.

Cutaneous neoplasms showing EWSR1 rearrangement

Rearrangements of the EWSR1 gene are found in an increasing number of human neoplasms, including several tumors that can involve the skin: Ewing sarcoma/primitive neuroectodermal tumor, angiomatoid (malignant) fibrous histiocytoma, myoepithelioma of soft tissue, and clear cell sarcoma. Although these tumors share this common genetic link, they have very different clinical features, morphology, immunophenotype, and sometimes fusion gene partners; these will be the subjects of this review.

Co-expression of multiple cytokines and their receptors in primary clear cell sarcoma of the pubic bone with features of a small round cell tumor

We present the case of an 81-year-old man with primary clear cell sarcoma (CCS) of the pubic bone with an associated aggressive clinical course. The patient's laboratory tests showed marked leukocytosis, elevated levels of C-reactive protein and multiple cytokines, including interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF). Histological examination showed monomorphic small cells predominantly arranged as a diffuse sheet with morphological features of a small round cell tumor (SRCT). Immunohistochemical staining indicated that the tumor cells were positive for HMB45, S100, Melan A, IL-6, IL-6 receptor, G-CSF, and G-CSF receptor and negative for cytokeratin (AE1/AE3) and epithelial membrane antigen. To the best of our knowledge, this is the first case report of aggressive primary CCS of the pubic bone with features of SRCT showing the production and co-expression of multiple cytokines and their receptors. Thus, we suggest that proliferation through an IL-6- and G-CSF-associated autocrine mechanism may play an important role in the aggressive clinical course and poor prognosis of some CCSs showing features of SRCT.

A rare case of primary clear cell sarcoma of the pubic bone resembling small round cell tumor: an unusual morphological variant

Background

Clear cell sarcoma (CCS) and malignant melanoma share overlapping immunohistochemistry with regard to the melanocytic markers HMB45, S100, and Melan-A. However, the translocation t(12; 22)(q13; q12) is specific to CCS. Therefore, although these neoplasms are closely related, they are now considered to be distinct entities. However, the translocation is apparently detectable only in 50%–70% of CCS cases. Therefore, the absence of a detectable EWS/AFT1 rearrangement may occasionally lead to erroneous exclusion of a translocation-negative CCS. Therefore, histological assessment is essential for the correct diagnosis of CCS. Primary CCS of the bone is exceedingly rare. Only a few cases of primary CCS arising in the ulna, metatarsals, ribs, radius, sacrum, and humerus have been reported, and primary CCS arising in the pubic bone has not been reported till date.

Case presentation

We present the case of an 81-year-old man with primary CCS of the pubic bone. Histological examination of the pubic bone revealed monomorphic small-sized cells arranged predominantly as a diffuse sheet with round, hyperchromatic nuclei and inconspicuous nucleoli. The cells had scant cytoplasm, and the biopsy findings indicated small round cell tumor (SRCT). Immunohistochemical staining revealed the tumor cells to be positive for HMB45, S100, and Melan-A but negative for cytokeratin (AE1/AE3) and epithelial membrane antigen. To the best of our knowledge, this is the first case report of primary CCS of the pubic bone resembling SRCT. This ambiguous appearance underscores the difficulties encountered during the histological diagnosis of this rare variant of CCS.

Conclusion

Awareness of primary CCS of the bone is clinically important for accurate diagnosis and management when the tumor is located in unusual locations such as the pubic bone and when the translocation t(12; 22)(q13; q12) is absent.

Malignant gastrointestinal neuroectodermal tumor: clinicopathologic, immunohistochemical, ultrastructural, and molecular analysis of 16 cases with a reappraisal of clear cell sarcoma-like tumors of the gastrointestinal tract

The clinical, histologic, immunophenotypic, ultrastructural, and molecular features of a distinctive gastrointestinal tumor are described. Sixteen patients, 8 women and 8 men aged 17 to 77 years (mean age, 42 y; 63% less than 40 y) presented with abdominal pain, intestinal obstruction, and an abdominal mass. Mean tumor size was 5.2 cm (range, 2.4 to 15.0 cm). The tumors arose in the small bowel (10), stomach (4), and colon (2) and were histologically characterized by a sheet-like or nested population of epithelioid or oval-to-spindle cells with small nucleoli and scattered mitoses. Five cases showed focal clearing of the cytoplasm. Scattered osteoclast-type multinucleated giant cells were present in 8 cases. The tumor cells were positive for S-100 protein, SOX10, and vimentin in 100% of cases, for CD56 in 70%, for synaptophysin in 56%, for NB84 in 50%, for NSE in 45%, and for neurofilament protein in 14% of cases. All cases tested were negative for specific melanocytic, gastrointestinal stromal tumors, epithelial, and myoid markers. Ultrastructural examination of 5 cases showed features of primitive neuroectodermal cells with clear secretory vesicles, dense-core granules, occasional gap junctions, and no evidence of melanogenesis. EWSR1 gene rearrangement was assessed by fluorescence in situ hybridization in 14 cases. Twelve cases (86%) showed split EWSR1 signal consistent with a chromosomal translocation involving EWSR1. One case showed extra intact signals, indicating that the nuclei possessed either extra copies of the EWSR1 gene or chromosome 22 polysomy. Only 1 case showed no involvement of the EWSR1 gene. Six cases demonstrated rearrangement of the partner fusion gene ATF1 (46%), and 3 showed rearrangement of CREB1 (23%); 2 cases lacked rearrangement of either partner gene. Clinical follow-up was available in 12 patients and ranged from 1.5 to 106 months. Six patients died of their tumors (mean survival, 32 mo; 83% less than 24 mo). At last follow-up, 4 patients were alive with regional, lymph node, and liver metastases, and 2 patients were alive with no evidence of disease. The tumor described here is an aggressive form of neuroectodermal tumor that should be separated from other primitive epithelioid and spindle cell tumors of the gastrointestinal tract. The distinctive ultrastructural features and absence of melanocytic differentiation serve to separate them from soft tissue clear cell sarcomas involving the gastrointestinal tract. The designation "malignant gastrointestinal neuroectodermal tumor" is proposed for this tumor type.

The pathology of melanoma

Although melanoma represents only 10% of all skin cancer diagnoses, it accounts for at least 65% of all skin cancer-related deaths. The number of new cutaneous melanoma cases projected during 2010 was 68,000-a 23% increase from the 2004 prediction of 55,100 cases. In 2015, the lifetime risk of developing melanoma is estimated to increase to 1 in 50. As the incidence of melanoma continues to rise, now more than ever, clinicians and histopathologists must have familiarity with the various clinical and pathologic features of cutaneous melanoma.

Soft tissue tumors of uncertain origin

Many soft tissue tumors of childhood lack obvious differentiation toward a defined mesenchymal tissue type or have a phenotype that does not correspond to any defined normal tissue. These challenging tumors are currently regarded as neoplasms of uncertain differentiation. Nonetheless, there have been great strides in the understanding of their pathologic and genetic features and biologic underpinnings. The application of new genetic information to the pathologic diagnosis among this group of tumors is an emerging area in diagnostic pediatric pathology. This article reviews the clinicopathologic features of tumors of uncertain and/or miscellaneous origin, with an emphasis on the unique aspects of these neoplasms in children and adolescents, use of diagnostic adjuncts, and differential diagnosis.

Clear cell sarcoma of the ileum: report of a case and review of the literature

INTRODUCTION

Clear cell sarcoma of the gastrointestinal tract (CCS-GI) is an extremely rare and aggressive tumor, which often mimics other neoplastic processes. Because of this feature, its real incidence may have been underestimated, especially in the past when genetic tests were less available than nowadays. To date, less then 30 cases have been described in the literature on the GI tract.

CASE PRESENTATION

We report the case of a 69-year-old woman who presented with active rectal bleeding. After a negative colonoscopy, the patient underwent a video-capsule endoscopy. The latter detected an ileal mass that was surgically resected. The microscopic appearance was consistent with a malignant mesenchymal neoplasm; immunohistochemistry was positive for S100 protein, CD56, and INI1. Fluorescence in situ hybridization showed a translocation involving the EWSR1 (Ewing sarcoma 1) gene region. All these findings were consistent with a CCS-GI.

CONCLUSION

Herein we present a case of CCS-GI, discuss its clinical and pathological features, and review the literature on the subject.

Primary clear cell sarcoma of humerus: case report

We report a case of primary clear cell sarcoma occurring in the humerus. A 20 year old girl was referred to our hospital two years ago with painless swelling of the soft tissue surrounding the proximal right humerus. The conventional radiographic image showed an ill-defined, aggressive, osteolytic lesion associated with a partial cortical defect of the proximal right humerus. Magnetic resonance imaging found an irregularly shaped extraosseous mass extending from the proximal shaft of the right humerus, penetrating through the destroyed bone and invading the biceps brachii. After preoperative chemotherapy, a total tumor resection, internal fixation and bone cement implantation were performed. Histological studies of the resected tumor found that fibrous septa divided into well-defined nests and polygonal and fusiform cells with clear cytoplasm. Immunohistochemical studies demonstrated strong positive cytoplasmic staining with S-100 and scattered positivity with HMB-45. These findings led to a final, definitive diagnosis of clear cell sarcoma of the humerus. After routine postoperative chemotherapy, a 2-year follow-up showed no metastasis. Our findings in this report point out that primary clear cell sarcoma can originate from within the humerus and that limb salvage surgery can obtain a good result.

Clear-cell sarcoma of the soft tissue--a rare diagnosis with a fatal outcome

Clear-cell sarcomas account for less than 1% of all soft tissue tumours. They most often occur in middle-aged adults as a deeply located lesion with predilection to the tendons and aponeuroses. The aim of the present study was to show possible influencing factors on the outcome after surgical treatment in a detailed case series. We reviewed the medical records of 11 patients with the diagnosis of a clear-cell sarcoma of the soft tissue. These cases were analysed with regard to age, gender, localisation, tumour size, recurrence free survival and overall survival. A minimum follow up of 12 months was achieved. The mean age at the point of diagnosis was 47.9 years. Metastases occurred after a mean of 19.2 months. In the cases with a tumour diameter >5 cm, metastases occurred earlier. When treated in a specialist centre, metastases occurred later. Patients died a mean of 18.4 months after developing metastatic disease. Patients with tumour size >5 cm at the point of primary diagnosis died earlier than patients with a tumour size <5 cm. It is important to detect clear-cell sarcomas as soon as possible and the final surgical treatment should be performed in a centre familiar with the treatment of soft tissue tumours not only to prolong overall survival, but also to treat the patient in a multiprofessional team.

Caffeine-potentiated chemotherapy for clear cell sarcoma: a report of five cases

BACKGROUND

Clear cell sarcoma is a rare malignant tumor of soft tissue which is most commonly encountered in the extremities, especially in the foot and ankle. This tumor is slow-growing and looks like a benign tumor; it is therefore often treated inadequately and its high rate of recurrence and metastases results in a poor prognosis. Caffeine has been used as a chemotherapy potentiator that inhibits DNA damage repair and enhances the cytocidal effects of anti-cancer drugs. This study reports the effect of caffeine-potentiated chemotherapy for clear cell sarcoma in five patients.

METHODS

Caffeine-potentiated chemotherapy was administered to five patients with clear cell sarcoma. Three to five courses of intra-arterial chemotherapy using cisplatin, doxorubicin and caffeine were administered preoperatively, at 3-week intervals. Conservatively, wide margin surgery was performed following the preoperative chemotherapy. Intravenous cisplatin and doxorubicin with caffeine were administered three to six times to the patients who responded to the preoperative chemotherapy. This study evaluated the response to chemotherapy, recurrence, metastasis and the overall prognosis in these five patients.

RESULTS

Four of the eligible patients responded to preoperative chemotherapy. Local recurrence occurred in only one of the five patients. Distant metastasis newly developed in one patient. All five patients survive.

CONCLUSION

Caffeine-potentiated chemotherapy can be effective treatment for clear cell sarcoma not only as initial therapy, but also as salvage therapy.

Biology and clinical relevance of the micropthalmia family of transcription factors in human cancer

Members of the micropthalmia (MiT) family of transcription factors (MITF, TFE3, TFEB, and TFEC) are physiologic regulators of cell growth, differentiation, and survival in several tissue types. Because their dysregulation can lead to melanoma, renal cell carcinoma, and some sarcomas, understanding why these genes are co-opted in carcinogenesis may be of general utility. Here we describe the structure of the MiT family of proteins, the ways in which they are aberrantly activated, and the molecular mechanisms by which they promote oncogenesis. We discuss how meaningful understanding of these mechanisms can be used to elucidate the oncogenic process. Because the expression of these proteins is essential for initiating and maintaining the oncogenic state in some cancer types, we propose ways that they can be exploited to prevent, diagnose, and rationally treat these malignancies.

Pathways to melanoma

Melanoma is one of the most aggressive and yet poorly understood of human malignancies. Advances in genomics has allowed a more nuanced understanding of the disease, moving beyond the traditional dysplastic nevus-to-melanoma model and identifying multiple divergent oncogenic pathways leading to melanoma. An understanding of the molecular mechanisms driving melanoma has opened the doors for the development of targeted therapeutic approaches. As we enter the era of personalized medicine, it will be critical for clinicians to both appreciate and be able to determine the molecular profile of their patients' melanoma because this profile will guide risk stratification, genetic counseling, and treatment customization. A review of the divergent pathways of melanoma development is presented here, with a particular emphasis on recently identified mutations, and their implications for patient care.

Primary clear cell sarcoma of the sacrum: a case report

Clear cell sarcoma, first described by Enzinger in 1965, is an uncommon malignant soft tissue neoplasm that displays melanocytic differentiation. It occurs predominantly in the soft tissue of the extremities in young adults or children. Primary clear cell sarcoma of the bone is extremely rare, only seven cases have been reported to our knowledge. We present here a case of a huge primary clear cell sarcoma of the sacrum arising in a 25-year-old man. The average percentage of melanin content in the tumor was 9.25 ± 6.71%, which resulted in hypointense signal in T2-weighted and heterogeneous hyperintense signal in T1-wieghted images of magnetic resonance imaging (MRI). The patient was treated with curettage of the mass and neither further radiotherapy nor chemotherapy had been provided. The patient had local regrowth of tumor at 9 months after surgery. To our knowledge, this is the first case of CCS in the axial skeleton documented in English literature.