Cutaneous epithelial tumors induced by vemurafenib involve the MAPK and Pi3KCA pathways but not HPV nor HPyV viral infection

The inhibitors of mutant BRAF that are used to treat metastatic melanoma induce squamoproliferative lesions. We conducted a prospective histopathological and molecular study on 27 skin lesions from 12 patients treated with vemurafenib. Mutation hot spots in HRAS, NRAS, KRAS, BRAF, and Pi3KCA were screened. HPV and HPyV infection status were also determined. The lesions consisted of 19 verrucal papillomas, 1 keratoacanthoma and 7 squamous cell carcinomas. No mutations were found within BRAF and NRAS. KRAS, HRAS, and Pi3KCA oncogenic mutations were found in 10 (83.3%), 7 (58.3%), and 4 (33.3%) patients respectively; however, these mutations were not consistent within all tumors of a given patient. Pi3KCA mutation was always associated with a mutation in HRAS. Finally, no correlation was found between the mutated gene or type of mutation and the type of cutaneous tumor or clinical response to vemurafenib. P16 protein level was not indicative of HPV infection. HPV was detected in only two lesions. Two cases had MCPyV, and one had HPyV7. In conclusion, neither HPV nor HPyV seem to be involved in the development of squamoproliferative lesions induced by verumafenib. By contrast, HRAS and KRAS play a predominant role in the physiopathology of these tumors.

Adult sinonasal soft tissue sarcoma: analysis of 48 cases from the French Sarcoma Group database

OBJECTIVE

The aim of this study was to determine the frequency of primary sinonasal adult sarcoma, identify histological subtypes, and analyze prognostic factors.

STUDY DESIGN

Retrospective review.

METHOD

Forty-eight adult sinonasal sarcomas included in the French Sarcoma Group database (Conticabase) were reviewed.

RESULTS

The most frequent tumor types were alveolar rhabdomyosarcoma (33.3%), embryonal rhabdomyosarcoma (14,6%), unclassified sarcoma (14.6%), and leiomyosarcoma (12.5%). All round cell tumors were rhabdomyosarcomas. The 5-year overall survival (OS), metastasis-free survival (MFS), and local recurrence-free survival (LRFS) rates were 62.3%, 73%, and 88.8%, respectively. Histotype was a prognostic factor for OS, MFS, and LRFS, with the worst prognosis associated with rhabdomyosarcomas, regardless of the subtype. The tumor grade influenced the OS and MFS. Surgery was a predictive factor for a complete response.

CONCLUSIONS

These results suggest that sinonasal tract should be considered as an unfavorable site for rhabdomyosarcoma. Moreover, surgery should always be considered in treatment.

Comparative evaluation of the new FDA approved THxID™-BRAF test with High Resolution Melting and Sanger sequencing

Background

Since patients diagnosed with BRAF V600E and V600K mutated advanced melanoma show response to treatment with MAP kinase inhibitors, several sensitive methods have been developed to determine the V600 allele status of melanoma patients. Vemurafenib (Zelboraf) and dabrafenib (Tafinlar) are specific BRAF V600 inhibitors recently approved by the US FDA as single agent treatments for unresectable or metastatic melanoma in patients with the BRAF V600 mutation.

Methods

We assessed the new CE THxID™-BRAF diagnostic test, which is also FDA-approved as a companion diagnostic test in the US under a specific reference and compared the results of this assay with both High Resolution Melting (HRM) and Sanger sequencing in 113 melanoma FFPE samples.

Results

Invalid results were observed in 0/113 specimen with HRM, 5/113 (4.4%) with Sanger sequencing, and 1/113 (0.9%) with the THxID™-BRAF test. Positive percentage agreement (PPA) was 93.5% (95% CI 82.5 - 97.8) for V600E and V600K mutations combined for the THxID™-BRAF test and HRM, and negative percentage agreement (NPA) was 100.0% (95% CI 94.5 - 100.0). For the THxID™-BRAF test and Sanger, PPA was 100.0% (95% CI 92.1 - 100.0) and NPA 100.0% (95% CI 94.2 - 100.0). One V600E sample identified by THxID™-BRAF test was detected as wild-type by HRM and uninterpretable by Sanger. All V600K (n = 3) were detected using the 3 different approaches. Finally, percent agreement values were not significantly different when using punches (n = 77) vs. slides (n = 36) or depending on samples characteristics such as pigmentation, necrosis, and tumor content.

Conclusions

This study demonstrated the high agreement between the FDA approved THxID™-BRAF assay, HRM, and Sanger sequencing. It has also highlighted the potential of THxID™-BRAF to be applied to a broader range of sample types than claimed in the current “instructions for use”, an extension that would require the ad hoc validation and approval.

[Radiation therapy for pleomorphic adenoma of the parotid]

Parotid pleomorphic adenoma is the most frequent tumor of salivary glands. The prognosis depends on the recurrences because they could lead to iatrogenic events (facial paralysis). Moreover the risk of malignant transformation increases with the number of local relapses. This article aims at reviewing histological and radiological criteria and the surgical techniques. To improve local control, adjuvant irradiation (in first intention or after recurrence) may be useful but is still controversial for benign tumors in young patients with a risk of radio-induced cancer. We listed studies in which adjuvant radiotherapy was used so as to define its place in the treatment strategy. Prognostic factors were found by some authors. Other studies have to be done before strong evidence-based recommendations are issued.

[Q fever: bone marrow characteristic granuloma]

Q fever is a worldwise zoonosis, caused by an obligate intracellular bacterium, Coxiella burnetii. In humans, acute disease, when symptomatic, can manifest by a flu-like illness, pneumonia or hepatitis. Patients with predisposing conditions can evolve with chronic disease, which major clinical presentation is endocarditis with negative routine blood cultures. Histological studies of Q fever based on infected organs biopsies (liver and bone marrow) have demonstrated a distinctive type of granuloma, typically appearing as a "doughnut" granuloma, characterized by a central clean space surrounded by inflammatory cells and rimmed with an eosinophilic fibrinoid material. We describe a 37-year-old man, admitted to hospital for persistent fever. Bone marrow biopsy showed the characteristic "doughnut" granuloma, suggesting a Q fever. Diagnosis was then confirmed by serological tests for C. burnetii.

Comparison of the PapilloCheck® assay with the digene HC2 HPV DNA assay for the detection of 13 high-risk human papillomaviruses in cervical and anal scrapes

The PapilloCheck® assay was compared with the Digene HC2 HPV DNA assay for the detection of 13 high-risk human papillomaviruses (HPV) in 240 samples, including 181 cervical scrapes and 59 anal scrapes. Overall, 75 (30.5%) samples were positive by the Digene HC2 HPV DNA assay: 34 (18.8%) cervical scrapes and 41 (69.5%) anal scrapes. By considering only the 13 high-risk HPV types detected by the Digene HC2 HPV DNA assay, 66 (27.5%) samples were positive by the PapilloCheck® assay: 27 (14.9%) cervical scrapes and 39 (66.1%) anal scrapes. Concordant results between the two assays were obtained for 225 (93.8%) samples with a Kappa coefficient value of 0.85, indicating an excellent agreement. By considering all the HPV types detectable by the PapilloCheck® assay, the overall prevalence of HPV was 34.2% (82/240): 21.0% (38/181) in cervical scrapes and 74.6% (44/59) in anal scrapes. Among the samples positive by the PapilloCheck® assay, a multiple HPV infection (2-9 HPV types) was identified in 43 of 82 (52.4%) samples, including 7 of 38 (18.4%) cervical samples, and 36 of 44 (81.8%) anal samples. The prevalence of high-risk HPV, as determined by the PapilloCheck® assay, was 17.6% (36/205) in samples with normal cytology, 83.9% (26/31) in samples with low-grade squamous intraepithelial lesions or atypical squamous cells of undetermined significance, and 100% (4/4) in samples with high-grade squamous intraepithelial lesions. The results obtained indicate that the PapilloCheck® assay may be considered as a reliable screening test for HPV detection and typing.

[Solitary fibrous tumor of the meninges: report of three cases]

The authors expose the clinical, radiological and histological presentation of three cases of solitary fibrous tumors of the meninges, initially thought to be meningiomas. Actually, these three cases show typical anatomoclinical features. The authors also mention the differential diagnosis, and recall the essential contribution of immunohistochemistry.

French brain tumor database: 5-year histological results on 25 756 cases

This work aimed to prospectively record all primary central nervous system tumor (PCNST) cases in France, for which histological diagnosis is available. The objectives were to (i) create a national registry and a network to perform epidemiological studies; (ii) implement clinical and basic research protocols; and (iii) harmonize the health care of patients affected by PCNST. For 5 years, 25 756 cases of newly diagnosed and histologically confirmed PCNST have been recorded. Histological diagnoses included glioma (48.9%), all other neuroepithelial tumors (5%), meningioma (28.8%), nerve sheath tumors (8.4%), lymphoma (3.2%) and others (5.7%). Cryopreservation was reported for 6018 PCNST specimens. Tumor resections (R) were performed in 78% cases, while biopsies accounted for 22%. Median age (MA), sex, percentage R and number of cryopreserved tumors were detailed for each histology; for example, out of 6053 glioblastomas (MA 63 years, male 59.4%, R 62%, 1611 were cryopreserved), and out of 37 atypical teratoid/rhabdoid tumors (MA 2 years, male 56.8%, R 94%, 17 were cryopreserved). This database or databank dedicated to PCNST cases contains detailed data on clinical, histological and other characteristics, such as the inclusion of data on cryopreserved specimens that are not available in other European registries. Therefore, this is a valuable resource that can be used for planning future epidemiological and clinical research.

[Polypoid PEComa: case report and literature review]

PEComa group is a heterogeneous group of rare mesenchymal tumors supposed to derive from perivascular cells and characterized by a coexpression of myogenic and melanocytic markers. We describe an 11-year-old female patient presenting a 2 cm ulcerated rectal polyp, exteriorized by anus, which was totally resected. Morphologically, this tumour was composed of cells arranged in nests or large cords separated by fibrous stroma, with abundant clear cytoplasms and with round regular small nuclei without atypia. There was no necrotic area and mitotic activity was very low. Immunohistochemically, the tumours cells stained for HMB45. Only 17 cases have been reported in literature and this case is the 18th. Here, we present a literature review focusing on both malignancy criteria and differential diagnosis.