Practical Approach to Histological Diagnosis of Peripheral Nerve Sheath Tumors: An Update.

Peripheral nerve sheath tumors encompass a wide spectrum of lesions with different biological behavior, including both benign and malignant neoplasms as well as the recent diagnostic category, i.e., "atypical neurofibromatous neoplasm with uncertain biologic potential" to be used only for NF1 patients. Neurofibromas and schwannomas are benign Schwann-cell-derived peripheral nerve sheath tumors arising as isolated lesions or within the context of classical neurofibromatosis or schwannomatoses. Multiple tumors are a hallmark of neurofibromatosis type 1(NF1) and related forms, NF2-related-schwannomatosis (formerly NF2) or SMARCB1/LZTR1-related schwannomatoses. Perineuriomas are benign, mostly sporadic, peripheral nerve sheath tumors that show morphological, immunohistochemical, and ultrastructural features reminiscent of perineurial differentiation. Hybrid tumors exist, with the most common lesions represented by a variable mixture of neurofibromas, schwannomas, and perineuriomas. Conversely, malignant peripheral nerve sheath tumors are soft tissue sarcomas that may arise from a peripheral nerve or a pre-existing neurofibroma, and in about 50% of cases, these tumors are associated with NF1. The present review emphasizes the main clinicopathologic features of each pathological entity, focusing on the diagnostic clues and unusual morphological variants.

Hirayama disease: Nosological classification and neuroimaging clues for diagnosis.

Hirayama disease (HD) is a rare, benign, and nonprogressive motor neuron disease (MND) affecting the upper limbs. It usually presents with weakness and amyotrophy in a single upper extremity with an insidious onset between adolescence and the third decade of life. Since its description in 1959, HD has been known under several names and eponyms in Europe and in Asian countries probably due to its heterogeneous clinical features. Thus, the unclear nosological classification makes challenging the differential diagnosis between HD and other neuromuscular conditions, such as MNDs. However, apart from the nosological difficulties and the lack of evidence-based guideline for diagnosis, the neuroimaging is the mainstay for the diagnosis of HD. Indeed, the specific findings on cervical flexion MRI usually lead to a prompt diagnosis. Here, we reviewed the nosological classifications of HD and its neuroimaging features. Also, we report a case of a 18-year-old boy who presented to our Clinic complaining of muscle weakness of the left distal upper limb without other neurological signs. The cervical MRI, in the neutral position, revealed a high T2 signal intensity in the C5-C7 cervical myelomeres as well as the loss of cervical lordosis, whereas, during neck flexion, it showed the anterior displacement of the posterior dura ad the post-gadolinium T1-weighted imaging enhancement of the posterior epidural plexus. These findings are typical for HD allowing the diagnosis as well as the differential diagnosis from other neuromuscular diseases.

Benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins.

A minority of mixed fibro-epithelial lesions of the breast lacks both fibroadenoma and phyllodes architectural patterns and have been previously labeled with different terms, including "hamartomas", "myoid/muscular hamartomas", "benign fibroadenomatous lesions" or "stromo-epithelial lesions of the breast". This study emphasizes the clinico-pathologic features of 5 cases of mammary benign fibro(stromo)-epithelial lesions sharing as a common morphologic theme the presence of minimally infiltrative margins due to the overgrowth of the stromal component into the surrounding fibro-fatty tissue. Notably the radiological features were suspicious for malignancy in 3 out of 5 cases. The following histologic features were seen in all cases: i) an epithelial component of benign glandular structures exhibiting the morphological spectrum of fibro-cystic disease; ii) a stromal component of bland-looking spindle cell myofibroblasts (vimentin + and α-smooth muscle actin +) set in a variably fibro-myxoid stroma. The present paper contributes to widen the morphological spectrum of the benign fibro-epithelial lesions of the breast, emphasizing the possibility that some cases, exhibiting a predominant myofibroblastic stromal component and minimally infiltrative margins, may be confused with other primary spindle cell mimickers of the breast. Accordingly, we propose the descriptive term "benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins" for these previously underrecognized lesions.

Ductal Carcinoma In Situ of the Breast: An Update with Emphasis on Radiological and Morphological Features as Predictive Prognostic Factors.

Ductal carcinoma in situ (DCIS) shows overlapping epidemiology with invasive ductal carcinoma of the breast, sharing similar risk factorssuch as age, mammographic density, family history, and hormonal therapy as well as genetic factors such as BRCA1/BRCA2, histotypes, and molecular subtypes such as luminal A and B, HER2 enriched, and basal-type, thus suggesting its potential precursor role. A small percentage of patients with a history of DCIS die without a documented intermediate diagnosis of invasive breast carcinoma (IBC). The increased risk of death is usually associated with ipsilateral recurrence such as IBC. The slightly variable incidence of DCIS in different countries is mainly due to a different diffusion of mammographic screening and variability of the risk factors. The majority of DCIS lesions are not palpable lesions, which can be only radiologically detected because of the association with microcalcifications. Mammography is a highly sensitive diagnostic procedure for detecting DCIS with microcalcifications, while magnetic resonance imaging (MRI) is considered more sensitive to detect DCIS without calcifications and/or multifocal lesions. The aim of the present overview was to focus on the clinical, radiological, and pathological features of DCIS of the breast, with an emphasis on the practical diagnostic approach, predictive prognostic factors, and therapeutic options.

Routine MRCP in the management of patients with gallbladder stones awaiting cholecystectomy: a single-centre experience.

OBJECTIVES: To assess the frequency of choledocolithiasis and the role of preoperative laboratory findings, ultrasound (US) and magnetic resonance cholangio-pancreatography (MRCP) in the detection of choledocolithiasis in patients with gallbladder stones awaiting cholecystectomy. METHODS: A consecutive sample of 104 patients underwent MRCP prior to cholecystectomy. The patients were classified into different groups on the basis of the risk of choledocolithiasis. A specialised doctor with more 10 years of experience performed the US interpretation and a radiologist performed the MRCP interpretation blinded to US or aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/alkaline phosphatase (ALP) results. A chi-square (χ2) test was performed to assess the statistical significance of differences in the frequency of choledocolithiasis based on laboratory findings, choledocal diameter on US and group risk. RESULTS: MRCP showed calculi in 7 out of 104 patients (6.7%), with no statistically significant differences between the high/moderate risk and low/no risk groups and between the patients with normal and altered laboratory findings or choledocal diameter on preoperative US. The sensitivity and specificity of AST/ALT [positive predictive value (PPV): 12%; negative predictive value (NPV): 94%], ALP (PPV: 7%; NPV: 94%), total serum bilirubin (PPV: 6%; NPV: 93%) and choledocal diameter (PPV: 20%; NPV: 94%) were, respectively, 28.6 and 94.8%, 85.7 and 17.5%, 14.3 and 93.8%, and 14.3 and 95.9%. CONCLUSIONS: MRCP is a reliable evaluation for the detection of common bile duct (CBD) stones, reducing the misdiagnosis of retained choledocholithiasis with normal biochemical predictors and US examination. MAIN MESSAGES: • MRCP is a non-invasive method for the detection of CBD stones. • Preoperative MRCP reduces the misdiagnosis of retained choledocholithiasis. • Detection of choledocholithiasis is mandatory prior to cholecystectomy to avoid surgical morbidity.

Experiences in US-guided percutaneous radiofrequency ablation of 44 renal tumors in 31 patients: analysis of predictors for complications and technical success.

PURPOSE: Preliminary clinical studies have shown the feasibility, safety, and efficacy of radiofrequency thermal ablation (RFA) of renal tumors, but only a few have analyzed the prognostic factors for technical success and there are no long-term results. Our objective was to statistically evaluate our mid-term results of percutaneous US-guided RFA in order to define predictors for complications and technical success. METHODS: We selected for treatment 44 tumors in 31 patients (24 with renal cell carcinoma, 7 with hereditary tumors, 15 with a solitary kidney), up to 5 cm in diameter. RESULTS: Eight adverse events occurred; 3 (6.8%) were major complications, successfully treated with interventional radiology procedures in 2 cases. Exophytic extension of the tumor was protective against complications (p = 0.040). Technical success was obtained in 38 lesions after one RFA session and in 39 (89%) after one more session, when possible. At the end of treatment, central extension was the only negative predictor for technical success (p = 0.007), while neither size >3 cm (p = 0.091) nor other prognostic factors were statistically significant. CONCLUSION: US-guided percutaneous RFA can be proposed for non-central renal tumors up to 5 cm, also in patients without surgical contraindications, thanks to a low incidence of complications and a high success rate. Randomized controlled trials versus surgery are now needed to investigate long-term comparative results.