A Rare Presentation of Primary Cutaneous Low-Grade Neuroendocrine Tumor of the External Auditory Canal.

OBJECTIVE: To describe the first case of a primary cutaneous low-grade neuroendocrine tumor (cLGNET) originating from the external auditory canal as well as our team's surgical management. PATIENT: A healthy 34-year-old female presented with a low-grade neuroendocrine tumor of her right external auditory canal (EAC) which extended from the posterior-superior aspect of the EAC into the middle ear. INTERVENTION: A complete otological examination was performed in addition to CT and MRI imaging. The low-grade neuroendocrine tumor was surgically biopsied and further surgery was recommended for complete resection. RESULTS: Audiogram revealed profound right sensorineural hearing loss. CT scan demonstrated complete opacification of the right EAC, middle ear, and mastoid air cells, dystrophic calcification in the mesotympanum overlying the cochlear promontory, and no associated osseous erosion. MRI revealed abnormal FLAIR hyperintensity and enhancement of the labyrinthine segment of the right facial nerve, cochlea, and horizontal and posterior semicircular canals. An enhancing mass opacifying the right EAC demonstrating restricted diffusion on diffusion-weighted image was also evident. Pathologic examination and immunohistochemical staining confirmed a diagnosis of primary cLGNET of the EAC. CONCLUSION: Primary cLGNETs of the external ear are exceedingly rare but should be considered if an adult patient presents with a mass in the EAC. Management should include early biopsy and surgical excision followed by histological and immunohistochemical confirmation.

Single Institutional Experience on Orbital Inflammatory Pseudotumor: Diagnostic and Management Challenge.

AIMS: Orbital inflammatory pseudotumor is considered a non-neoplastic inflammatory process. The finding of clonality of B or T-cell receptors in cases pathologically diagnosed as orbital inflammatory pseudotumor has unknown clinicopathologic significance. We sought to investigate potential B and T-cell clonality and concomitant diseases in cases pathologically diagnosed as orbital inflammatory pseudotumor. METHODS: Cases diagnosed as orbital inflammatory pseudotumor at our institution were retrospectively analyzed. Hematoxylin and eosinstained slides, immunohistochemically stained slides and polymerase chain reactions on cell block material for the investigation of clonality of B and T-cell receptors were evaluated, to confirm the diagnosis and investigate the prevalence of concomitant diseases. RESULTS: A total of 13 cases showing characteristic histopathologic features of orbital inflammatory pseudotumor were identified. CD138, IgG, and IgG4 showed varying numbers of plasma cells in each case, with 5 cases (5/13, 38%) exhibiting relative increase in the presence of IgG4 plasma cells. However, no cases showed diagnostic findings of IgG4-related disease (IgG4-RD). polymerase chain reactions analysis showed clonal B-cell populations in 2 cases (2/13, 15%). No cases showed anaplastic lymphoma kinase expression by immunohistochemistry. There were no clinical reports of progression to lymphoma or development of systemic IgG4-RD in any of the patients (average follow-up of 300 days), with 38% of patients showing systemic autoimmune conditions. CONCLUSION: A small but significant percentage of typical orbital inflammatory pseudotumor on histology showed B-cell clonality on polymerase chain reactions analysis of B-cell receptors, or features suggestive, but not diagnostic of IgG4-RD. Close follow-up of these patients to identify development of lymphoma, systemic IgG4-RD, or other rheumatologic conditions may be clinically warranted.

Hepatocellular carcinoma with biliary and neuroendocrine differentiation: A case report.

BACKGROUND: Liver tumors with dual differentiations [combined hepatocellular carcinoma (HCC) and cholangiocarcinoma] are common. However, liver tumors that exhibit hepatocellular, biliary, and neuroendocrine differentiation are exceedingly rare, with only three previous case reports in the literature. CASE SUMMARY: A 65-year-old female with a previous history of hepatitis C and a distant history of low grade, well-differentiated rectal neuroendocrine tumor was found to have two liver lesions in segment 4 and segment 7 on imaging. Serum alpha-fetoprotein and chromogranin A were elevated. Biopsy of the larger lesion in segment 4 revealed a high-grade tumor, with morphologic and immunohistochemical features of a neuroendocrine tumor. Given the previous history of rectal neuroendocrine tumor, imaging investigation, serologic markers, and biopsy findings, metastatic neuroendocrine tumor was considered. Subsequent regional resection of these hepatic lesions revealed the segment 4 lesion to be a HCC with additional biliary and neuroendocrine differentiation and the segment 7 lesion to be a cholangiocarcinoma with neuroendocrine differentiation. Follow-up of the patient revealed disease recurrence in the dome of the liver and metastasis in retro-pancreatic lymph nodes. The patient eventually expired due to complications of chemotherapy. CONCLUSION: HCC cases with additional biliary and neuroendocrine differentiation are exceedingly rare, posing a diagnostic challenge for clinicians and pathologists.