Subcutaneous porocarcinoma clinically presenting as a soft tissue tumor

Porocarcinoma is a rare malignancy with glandular adnexal differentiation. A 38‐year‐old Japanese man noticed a subcutaneous mass in right inguinal region about 20 years prior to being examined. Radiological examinations demonstrated the mass, 11 × 10 cm in size, was in the subcutaneous fat tissue. Recently, the mass grew rapidly, and it was biopsied by an orthopedist based on clinical diagnosis of primary soft tissue tumor. Histopathological examination of the resected specimens also revealed that the tumor lacked involvement to the skin. Microscopically, the tumor was mainly composed of poroid cells with partially obvious squamous differentiation, accompanied by focal ductal structures immunoreactive for CEA and EMA. The tumor contained a low‐grade area consisting of poroid cells and high‐grade area with squamous differentiation. This histopathological heterogeneity suggested malignant transformation from poroma. The patient had the tumor in almost same size over the period of 20 years, which is the longest in the previous reports. This unique case of subcutaneous porocarcinoma is reported.     

Detection of lymphatic invasion in resected cases of primary pancreatic cancer based on immunohistochemistry of D2-40

We investigated the presence of lymphatic invasion detected by D2-40 immunostaining compared to conventional hematoxylin-eosin (HE) staining in primary pancreatic cancer. We also compared the alkaline phosphatase-fast red detection method with the 3,3′-diaminobenzidine (DAB) detection method. We reviewed 25 cases of pancreatic cancer with lymph node (LN) metastases and 15 cases without LN metastases and evaluated the detection rate of lymphatic invasion by HE stain slide alone and D2-40 immunostains. Regarding the cases with positive LN metastasis, 4 (16%) of the 25 cases showed lymphatic invasion by HE slide alone, whereas 7 cases (28%) demonstrated positive lymphatic invasion by D2-40 immunostain. On the other hand, even in cases with negative LN metastasis, 3 of the 15 cases revealed lymphatic invasion by D2-40 immunostaining. Lymphatic invasion was easily detected by alkaline phosphatase-fast red technique, especially at the lower magnification. Regarding the location of lymphatic invasion, it was recognized not only at the peripheral portion but also in the central part of the tumors by D2-40 immunostains; this was difficult to identify by HE stain slide alone. Our study indicates that lymphatic invasion may be overlooked when only HE stain slides are used. In addition, the alkaline phosphatase-fast red detection method (vivid red color) is a distinctive advantage compared with the DAB detection method (brown color), especially in detecting lymphatic invasion at the lower magnification.     

Acoustic radiation force impulse elastography of the liver: can fat deposition in the liver affect the measurement of liver stiffness?

Purpose  

The aim of this study was to compare acoustic radiation force impulse (ARFI) results between livers with and without fat deposition.     

Transient Respiratory-motion Artifact and Scan Timing during the Arterial Phase of Gadoxetate Disodium-enhanced MR Imaging: The Benefit of Shortened Acquisition and Multiple Arterial Phase Acquisition

Purpose:To investigate whether shortened acquisition or multiple arterial phase acquisition improves image quality of the arterial phase compared with conventional protocol.Methods:This retrospective study was approved by the relevant Institutional Review Board. A total of 615 consecutive patients who underwent gadoxetate disodium-enhanced MRI including one of the following three sequences in three different periods were included: (i) conventional liver acquisition with volume acceleration (LAVA) (between October 2014 and January 2015, n = 149), (ii) Turbo-LAVA (between March and August 2016, n = 216), and (iii) differential sub-sampling with Cartesian ordering (DISCO) (between January and September 2015, n = 250). We monitored the respiratory bellows waveform during breath holding for each patient and recorded breath-hold fidelity of the patients. Two radiologists independently evaluated the degree of respiratory artifact and scan timing on the arterial phase and compared them between the three protocols (i.e., conventional LAVA, Turbo-LAVA, and DISCO), with conventional LAVA as control.Results:The ratio of patients with breath-hold failure was not significantly different among the three protocols (P = 0.6340 and 0.1085). Respiratory artifact was significantly lower in DISCO than in conventional LAVA (P = 0.0424), while there was no significant difference between Turbo-LAVA and conventional LAVA (P = 0.2593). The ratio of adequate scan timing and diagnosable image defined as no or mild artifact and adequate scan timing were higher in DISCO than in conventional LAVA (P = 0.0025 and 0.0019), while there was no significant difference between Turbo-LAVA and conventional LAVA (P = 0.0780 and 0.0657).Conclusion:Compared with conventional protocol, multiple arterial phase acquisition (DISCO) obtained a higher number of diagnosable images by reducing respiratory motion artifact and optimizing the scan timing of arterial phase.     

Outcome of hypovascular hepatic nodules with positive uptake of gadoxetic acid in patients with cirrhosis

Objectives

To evaluate the longitudinal risk to patients with cirrhosis of hypervascular hepatocellular carcinoma (HCC) developing from hypovascular hepatic nodules that show positive uptake of gadoxetic acid (hyperintensity) on hepatocyte phase images.

Methods

In 69 patients, we evaluated findings from serial follow-up examinations of 633 hepatic nodules that appeared hypovascular and hyperintense on initial gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) until the nodules demonstrated hypervascularity and were diagnosed as hypervascular HCC. Cox analyses were performed to identify risk factors for the development of hypervascular HCCs from the nodules.

Results

The median follow-up was 663 days (range, 110 to 1215 days). Hypervascular HCCs developed in six of the 633 nodules (0.9 %) in five of the 69 patients. The only independent risk factor, the nodule’s initial maximum diameter of 10 mm or larger, demonstrated a hazard ratio of 1.25. The one-year risk of hypervascular HCC developing from a nodule was 0.44 %. The risk was significantly higher for nodules of larger diameter (1.31 %) than those smaller than 10 mm (0.10 %, p?<?0.01).

Conclusions

Hypervascular HCC rarely develops from hypovascular, hyperintense hepatic nodules. We observed low risk even for nodules of 10 mm and larger diameter at initial examination.

Key Points

? Hypervascularization was rare on follow-up examination of hypovascular, hyperintense nodules ? The risk of hypervascularization in a nodule increased with large size ? Hypovascular, hyperintense nodules require neither treatment nor more intense follow-up