Diagnostic approach in TFE3-rearranged renal cell carcinoma: a multi-institutional international survey.

Transcription factor E3-rearranged renal cell carcinoma (TFE3-RCC) has heterogenous morphologic and immunohistochemical (IHC) features.131 pathologists with genitourinary expertise were invited in an online survey containing 23 questions assessing their experience on TFE3-RCC diagnostic work-up.Fifty (38%) participants completed the survey. 46 of 50 participants reported multiple patterns, most commonly papillary pattern (almost always 9/46, 19.5%; frequently 29/46, 63%). Large epithelioid cells with abundant cytoplasm were the most encountered cytologic feature, with either clear (almost always 10/50, 20%; frequently 34/50, 68%) or eosinophilic (almost always 4/49, 8%; frequently 28/49, 57%) cytology. Strong (3+) or diffuse (>75% of tumour cells) nuclear TFE3 IHC expression was considered diagnostic by 13/46 (28%) and 12/47 (26%) participants, respectively. Main TFE3 IHC issues were the low specificity (16/42, 38%), unreliable staining performance (15/42, 36%) and background staining (12/42, 29%). Most preferred IHC assays other than TFE3, cathepsin K and pancytokeratin were melan A (44/50, 88%), HMB45 (43/50, 86%), carbonic anhydrase IX (41/50, 82%) and CK7 (32/50, 64%). Cut-off for positive TFE3 fluorescent in situ hybridisation (FISH) was preferably 10% (9/50, 18%), although significant variation in cut-off values was present. 23/48 (48%) participants required TFE3 FISH testing to confirm TFE3-RCC regardless of the histomorphologic and IHC assessment. 28/50 (56%) participants would request additional molecular studies other than FISH assay in selected cases, whereas 3/50 participants use additional molecular cases in all cases when TFE3-RCC is in the differential.Optimal diagnostic approach on TFE3-RCC is impacted by IHC and/or FISH assay preferences as well as their conflicting interpretation methods.

Cranial nerve VI palsy as an initial presentation of necrotizing sarcoid granulomatosis in a 14-year-old female: case report and literature review.

OBJECTIVES: We describe a case of pediatric necrotizing sarcoid granulomatosis (NSG) presenting with right cranial nerve VI palsy and multiple lung nodules, successfully treated with corticosteroids. METHODS: This is a descriptive case report of one patient with review of the literature. RESULTS: A 14-year-old Caucasian female presented with complaints of pain on inspiration and dyspnea on exertion, as well as diplopia that was worse with right gaze. The patient presented to our emergency department with persistent diplopia and was found to have stable right cranial nerve VI palsy. CTA showed multiple pulmonary nodules. Despite continued extensive multispecialty work-up, the patient׳s cranial nerve VI palsy had not resolved, thus tissue confirmation via lung biopsy was performed. Pathologic diagnosis revealed necrotizing sarcoid granulomatosis. The patient was subsequently started on intravenous corticosteroids, which led to the rapid resolution of her presenting symptoms. CONCLUSIONS: Necrotizing sarcoid granulomatosis is a multisystem organ disease that is rare in children. Pathology commonly reveals epithelioid noncaseating granuloma and granulomatous vasculitis with necrosis. We report an unusual presentation involving sixth nerve palsy in a 14-year-old girl. Diagnosis was determined and confirmed by histopathology of a pulmonary nodule biopsy. This is the first case to our knowledge of NSG presenting with cranial nerve palsy in a pediatric patient.