Lymphnode metastasis of thyroid cancer misinterpreted as lateral aberrant thyroid 40 years before identification of primary tumor. Case report and review of the literature

The differential diagnosis between lateral ectopic thyroid tissue with orthotopic normal gland and metastatic thyroid carcinoma is challenging. Lateral cervical site is a very rare location for ectopic tissue since only a few cases have been reported. The peculiarity of this clinical case is the finding of a thyroid carcinoma forty years after surgical resection of the ectopic thyroid lesion. This asynchronous association, never reported in literature, raises the question of the differential diagnosis between a true ectopic aberrant thyroid and an early lymph node metastasis from an occult thyroid carcinoma, evident in the primitive site many years later. Several elements, which will be matter of discussion, seem to favour the latter hypothesis. This case, although isolated, suggests that any lateral cervical mass, comprising thyroid tissue, should be regarded as a metastasis of thyroid carcinoma until proven otherwise. Carefull investigation of thyroid gland is mandatory.

Oil Red O Is a Useful Tool to Assess Donor Liver Steatosis on Frozen Sections During Transplantation

Oil Red O is a useful tool to assess donor liver steatosis on frozen sections during transplantation. Steatosis is a frequent finding in liver evaluation during transplantation, accounting for 9% to 26% of biopsied donor liver. The degree of macrovesicular steatosis is classified as mild, moderate, and severe; the latter is considered an absolute contraindication to liver transplantation because it is associated with poor allograft outcome. Because of the scarcity of organs, there is a debate whether livers with less severe macrovesicular steatosis are still suitable for transplant. Consequently, tools or methods that allow a more accurate intraoperative assessment of steatosis on frozen sections are mandatory. The aim of this study is to improve intraoperative evaluation of steatosis during transplantation using Oil Red O stain on liver biopsies.

METHODS

Twenty consecutive liver biopsies of donors were collected during transplantation procedures from September 2017 to February 2018 at the Institute of Pathology of the University and Hospital Trust of Verona, Italy. Each liver biopsy was cut at a different thickness (3, 5, and 8 μm) and stained with both Oil Red O and conventional hematoxylin and eosin for intraoperative consultation. The degree (percentage of hepatocytes involved) of fatty changes was recorded. The results obtained during the intraoperative consultation were finally compared with the formalin-fixed and paraffin-embedded permanent section.

RESULTS

Assessment of steatosis on hematoxylin and eosin frozen sections was reported as mild in 17 cases (85%), moderate in 2 cases (10%) and severe in 1 case (5%). Oil Red O frozen sections reported the following results: mild steatosis in 16 cases (80%), moderate in 2 cases (10%), and severe in 2 cases (10%). The percentage of liver steatosis obtained with Oil Red O was consistent in all cases with that of the permanent sections. The staining procedure for Oil Red O required approximately 18 minutes.

CONCLUSIONS

Oil Red O special stain is a fast and inexpensive tool to improve the assessment of steatosis on frozen biopsies during liver transplantation.

Metastatic malignant melanoma to the gallbladder. Case report and review of the literature

Solitary metastasis of malignant melanoma (MM) to the gallbladder (GB) is rare and generally originates from skin melanoma. MM is a neoplasm with an often unpredictable course and metastases can potentially affecting all organs. The occurrence of metastasis in the GB is unusual and has only been exceptionally reported in the literature. We describe a case of an 86-year-old man with an isolated MM metastasis located within the GB presenting with symptoms mimicking acute cholecystitis. Anamnestically, he presented a history of malignant melanoma (Clark level III) resected from his left leg 17 years ago. Furthermore we provide a review of the literature with a focus on diagnostic clues to distinguish between primary versus secondary GB MMs and on the best surgical management that should be used.

Fast Chromotrope Aniline Blue Special Stain Is a Useful Tool to Assess Fibrosis on Liver Biopsy During Transplantation

BACKGROUND

Assessment of potential liver allograft donors with frozen sections has clinical relevant consequences for the transplant recipient. Several clinical risk factors have been identified that increase the risk of transplantation failure and it is critical for the pathologist to become familiar with the histologic criteria for donor liver suitability. In this setting an accurate and reliable assessment of fibrosis is crucial. We sought to report the value of the rapid chromotrope aniline blue stain (CAB) in a transplantation clinical work-flow for scoring liver fibrosis.

MATERIALS AND METHODS

Twenty consecutive intraoperative donor liver biopsy specimens were evaluated by a pathologist at the Transplant Pathology Board Room, AOUI Verona, during 24-hour on-call service. The stage of fibrosis was evaluated according to Ishak score ranging from 0 to 6 (absent to cirrhosis) using hematoxylin and eosin stain (H&E) plus rapid CAB special stain. After a 3-week washout period, only the slides stained with H&E were re-assessed for fibrosis stage by the same pathologist blinded to donor patient data.

RESULTS

Combination H&E-CAB staging fibrosis score was higher in 20%, lower in 10%, and the same in 70% of biopsy specimens as determined using only H&E stain alone. Rapid CAB stain takes 20 minutes longer than H&E stain alone.

CONCLUSIONS

CAB staining may be performed on frozen tissue from liver biopsy during a transplantation process without a significant delay in diagnosis. Combination H&E-CAB staining improves sensibility of interpretation of fibrosis.

Ependymoma with diffuse signet-ring features: report of a case and review of the literature

Signet-ring cell ependymoma is a rare variant of ependymoma with only seven cases described in literature. Biological behavior and prognosis of this entity are not well-known until now. We present a case of a 49-year-old female with a history of headache and gait instability. Magnetic resonance imaging showed an upper cervical tumor with cystic component and mural nodule. The patient underwent surgery. Microscopically some cells displayed an eccentric nucleus compressed to the periphery by vacuolated cytoplasm. Perivascular pseudorosettes and ependymal rosettes were seen only focally. The cells were positive for glial fibrillary acidic protein and epithelial membrane antigen. The diagnosis was ependymoma with diffuse signet-ring features, grade II according to the World Health Organization. It may be difficult to diagnose this unusual variant of ependymoma especially on small biopsies or frozen sections. A complete examination of the specimen is recommended with immunohistochemical confirmation to rule out potential morphologic mimics, such as metastatic adenocarcinomas and gliomas in the differential diagnosis.

Oncocytic papillary renal cell carcinoma: potential pitfall in small enucleation

OBJECTIVE

We describe an emerging entity, recently recognized as a pitfall in the diagnostic practice among eosinophilic renal cell tumours.

METHODS

A 60-year-old male underwent enucleation of a 1.2 cm nodule. Immunohistochemistry and FISH analysis were performed.

RESULTS

Histology revealed a neoplasm composed of large cells with eosinophilic cytoplasm, Fuhrman grade 3, arranged in papillae. At the immunohistochemical level, cells showed positivity for AMACR and CD10. Fluorescence in situ hybridization (FISH) demonstrated gains of chromosomes 7 and 17 and loss of Y. A diagnosis of oncocytic papillary renal cell carcinoma was made.

CONCLUSIONS

The distinction between renal oncocytoma and oncocytic papillary renal cell carcinoma is of substantial importance because of their different behaviour and prognosis, since the latter has malignant potential. Although the available evidence supporting tumour enucleation as the surgical treatment for renal cortical tumours < or = 4 cm, due to aforementioned clinicopathological features such tumours need to be evaluated using appropriate immunophenotypical and cytogenetic analyses.