Soft Tissue Special Issue: Chondroid Neoplasms of the Skull.

Clinically, radiologically, and pathologically, chondroid neoplasms of the skull can be diagnostically challenging due to overlapping features in each of these domains. Compounding the problem for the pathologist, there is also significant morphologic, immunophenotypic, and molecular genetic overlap between benign and malignant cartilaginous lesions, and the majority of these lesions are encountered quite rarely in routine surgical pathology practice. Each of these factors contribute to the diagnostic difficulty posed by these lesions, highlighting the importance of radiologic-pathologic correlation in the diagnosis. This review is intended to provide an update for surgical pathologists on some of the most commonly encountered chondroid neoplasms in the skull, and includes the following lesions: chondromyxoid fibroma, synovial chondromatosis, chondrosarcoma and variants, and chordoma and variants. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

Ear and Temporal Bone Pathology: Neural, Sclerosing and Myofibroblastic Lesions.

Neural, sclerosing, and myofibroblastic lesions of the ear and temporal bone present diagnostic challenges for both clinicians and pathologists due to significant overlap in their clinical presentations, histologic appearances, and immunohistochemical profiles. While some of these lesions, such as schwannomas, are relatively common, others are rendered even more difficult because they are encountered very rarely in routine surgical pathology practice. This review is intended to provide an update on the pathology of some of the most commonly encountered primary diagnostic entities for the ear and temporal bone, and includes the following neural lesions: schwannoma, meningioma, and encephalocele/meningocele. Sclerosing lesions that will be discussed include spindle cell and sclerosing rhabdomyosarcoma, sclerosing epithelioid fibrosarcoma, and sclerosing paraganglioma. Finally, myofibroblastic lesions that will be reviewed are nodular fasciitis, IgG4-related disease, and solitary fibrous tumor. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

Metastatic carcinoma resulting in hepar lobatum.

Hepar lobatum is an acquired liver deformity mostly known as the end-stage of tertiary syphilis. The authors report two cases of hepar lobatum resulting from metastatic mammary ductal carcinoma in the liver and reassess the clinicopathologic features of seven previously reported cases (two in the German language). A liver of near-normal weight with an irregularly lobulated contour, capsular indentations/crevices from which intersecting (carcinoma-bearing) fibrous septa extended deep into the parenchyma, a predominant centrifugal distribution of lesional areas, and many septa abutting on the degenerated center of tumor nodules were the salient gross features. No significant tumor/fibrous occlusion of intrahepatic branches of portal or hepatic veins, nor cirrhotic type nodular hepatocellular regeneration was observed. Both of these patients experienced a drastic decrease in CEA serum levels during multiagent palliative chemotherapy. In one patient, abundant macrophages in conjunction with minimal residual tumor were present within intrahepatic septa. The pathogenesis of this condition appears largely related to an active phase of chemo-induced tumor regression with subsequent tissue collapse, followed by an organizing phase of healing and scar contraction.