Oxyphil cells in primary hyperparathyroidism: a clinicopathological study

BACKGROUND

The role of oxyphil cells (OxC) in primary hyperparathyroidism (PHPT) still remains controversial. Historically, they were believed to be involuted cells. However, they could play an important role in hormone secretion. The clinical behavior of OxC-rich adenomas and preoperative PHPT localization tests have been widely studied. The aim of this study is to analyze the implications of OxC in PHTP.

METHODS

A retrospective cohort study of patients undergoing parathyroidectomy for PHPT was conducted. Additionally, we included normal glands removed in the context of PHPT or inadvertently during a thyroidectomy. All glands were reviewed independently by three researchers, performing a semi-quantitative analysis of the percentage of OxC. Groups with < 25% OxC and > 75% OxC were compared.

RESULTS

In the period 2010-2017, 238 patients and 261 removed glands were included (8.8% OxCA > 75%). There were no differences in symptomatology and levels of preoperative calcium, parathormone, or 25-OH vitamin. Patients with OxCA > 75% had worse preoperative glomerular filtration rate (81.2 vs. 69.7 mL/min/1.73 m²; p = 0.043). They also had a trend towards larger size and weight (17 vs. 20 mm, p = 0.135 and 562 vs. 875 mg, p = 0.495), while ultrasound was found to have better accuracy (48.3% vs. 73.7%; p = 0.035). There were no normal glands with a content of OxC > 75%.

CONCLUSIONS

Our study suggests that phosphocalcic metabolism is not influenced by the presence of a high content of OxC in the parathyroid glands. A high content of OxC seems to be exclusive to pathologic glands and could be related to the deterioration of renal function in patients with PHPT.

Oncocytic Renal Cell Carcinoma with Tubulopapillary Growth Having a Fat Component

We report a rare case of oncocytic renal cell carcinoma (RCC) with tubulopapillary growth in the background of tuberculous end-stage kidney disease. Histology of the renal mass consisted of oncocytic cells forming solid, thin tubules and rare papillae. The tumor had abundant eosinophilic oncocytic cells containing occasional cytoplasmic Mallory body–like hyaline globules and a tiny focus of clear cells with intervening mature fat. Both the oncocytic cells and clear cells were immunoreactive for a-methylacyl-CoA racemase, vimentin, pancytokeratin, and CD10, and negative for transcription factor E3, CD15, human melanoma black 45, and c-kit. Mallory body–like hyaline globules were positive for CAM 5.2 and periodic acid–Schiff with or without diastase. Ultrastructurally, the tumor cells had abundant cytoplasmic mitochondria. The present case is a rare case of oncocytic RCC with tubulopapillary growth pattern. The case is unique in that the tumor was mixed with fat component, which is not common in RCC and thus can lead to misdiagnosis.

Melanotic oncocytic metaplasia of the nasopharynx: a report of three cases and review of the literature

Melanotic oncocytic metaplasia of the nasopharynx is a rare condition which is characterized by the presence of usually a small, brown to black colored pigmented lesion around the Eustachian tube opening. Although it is a benign lesion, it may be clinically misdiagnosed as malignant melanoma. Microscopically, melanotic oncocytic metaplasia is a combination of oncocytic metaplasia of the epithelium of the gland and melanin pigmentation in its cytoplasm. In our present study, we report three cases of melanotic oncocytic metaplasia of the nasopharynx. All the three cases occurred in men and were presented as multiple black pigmented lesions around the torus tubarius. Microscopically, mucous glands with diffuse oncocytic metaplasia and numerous black pigments were observed. No cellular atypia was observed. Immunohistochemically, the scattering of S-100 protein-positive, and human melanoma black 45-negative dendritic melanocytes was evident. This is the first report of cases of melanotic oncocytic metaplasia of the nasopharynx in Korea.

Large oncocytic adrenocortical tumor with uncertain malignant potential

Oncocytoma is a neoplasm consisting of oncocytes that is found in the salivary gland, kidney, and thyroid. Adrenocortical oncocytoma is particularly uncommon, and most cases reported are benign and nonfunctioning. Here, we report a 20 cm adrenal mass associated with necrosis that was identified as an oncocytic adrenocortical tumor with uncertain malignant potential through histopathological evaluation after its resection.