Mesothelial derived adenomatoid tumour in a location devoid of mesothelium: adrenal adenomatoid tumour

Primary adenomatoid tumor of the adrenal gland: A case report and literature review

RATIONALE

Adenomatoid tumors are rare benign tumors, mainly involving the reproductive tract, such as the epididymis in men and the uterus and fallopian tubes in women. However, a few cases can occur outside the reproductive tract. Herein, we report a rare case of a primary adenomatoid tumor of the adrenal gland.

PATIENT CONCERNS

A 50-year-old man underwent ultrasound examination and was found to have a right adrenal mass without elevated blood pressure, weakness after fatigue, frequent nocturnal urination urgency, pain, or a history of hematuria. The patient's general health was normal. Computed tomography revealed a polycystic mixed-density lesion in the right adrenal region, approximately 7.3 × 4.5 cm in size.

DIAGNOSES

Based on the clinical information, morphological features, and immunohistochemistry results, a pathological diagnosis of primary adenomatoid tumor of the adrenal gland was made.

INTERVENTION

Excision of the right adrenal gland and tumor through the 11 ribs.

OUTCOMES

The patient's postoperative course was uneventful.

LESSONS

Preventing misdiagnosis adenomatoid tumors with other types of adrenal gland tumors or metastatic tumors is imperative. Morphological and immunohistochemical features can help diagnose primary adenomatoid tumors of the adrenal gland.

Adenomatoid Tumor of the Adrenal Gland: Report of Two Cases and Review of the Literature

Adenomatoid tumor (AT) is an uncommon benign neoplasm of mesothelial origin, usually occurring in the female and male genital tracts. Extragenital localization such as the adrenal gland is extremely rare. Until now, only 39 cases of adrenal AT have been reported in the English literature. Here we report two novel cases of adrenal AT that occurred in male patients aged 30 and 31 years. The tumors were discovered incidentally by computed tomography (CT). Macroscopically, the tumors were unilateral and solid, and the greatest dimension of the tumors was 3.5 and 8.0 cm, respectively. Histologically, the tumors consisted of angiomatoid, cystic, and solid patterns and infiltrated the adrenal cortical or medullary tissue. The tumor cells had low nuclear/cytoplasmic ratio, with no pathological mitosis or nuclear pleomorphism. Thread-like bridging strands and signet-ring-like cells could be seen. Immunohistochemically, the tumor cells were positive for epithelial markers (AE1/AE3, CK7) and mesothelial markers (D2-40, calretinin, and WT-1). The Ki-67 index was approximately 1 and 2%, respectively. The differential diagnosis of adrenal AT includes a variety of benign and malignant tumors. The patients had neither local recurrence nor distant metastasis at 21 and 8 months after removal of the tumor. In the literature review, we comprehensively summarized the clinical, morphological, immunohistochemical, and prognostic features of adrenal AT. Adrenal ATs are morphologically and immunophenotypically identical to those that occur in the genital tracts. Combining the histology with immunohistochemical profiles is very supportive in reaching the diagnosis of this benign tumor, helping to avoid misdiagnosis and overtreatment.

Adenomatoid tumor of the skin: Differential diagnosis of an umbilical erythematous plaque

Adenomatoid tumors are benign tumors of mesothelial origin that are usually encountered in the genital tract. Although they have been observed in other organs, the skin appears to be a very rare location, with only one case reported in the literature to our knowledge. We report a second case of an adenomatoid tumor, arising in the umbilicus of a 44-year-old woman. The patient presented with an 8-month-old erythematous and firm plaque under the umbilicus. A skin biopsy showed numerous microcystic spaces dissecting a fibrous stroma and lined by flattened to cuboidal cells with focal intraluminal papillary formation. This little-known diagnosis constitutes a diagnostic pitfall for dermatopathologists and dermatologists, and could be misdiagnosed as other benign or malignant entities. Through this case report, a practical approach and diagnostic keys have been devised to avoid misdiagnosis and overtreatment.

[A CASE OF ADRENAL ADENOMATOID TUMOR DIAGNOSED BY IMMUNOHISTOCHEMICAL EVALUATION]

An adenomatoid tumor is a benign tumor of mesothelial derivation, typically found in the genital track. However, though extremely rare, an adenomatoid tumor can be found in the adrenal gland, making it difficult to clinically and radiologically differentiate it from an adrenocortical tumor or a pheochromocytoma prior to surgery. We encountered a-52-year old man with an adenomatoid tumor in the adrenal gland, who presented with an incidentally discovered left adrenal mass revealed by PET-CT from his regular health examinations. He had been diagnosed with paroxysmal hypertension two years before and was being treated with a hypolipidemic agent. Abdominal computed tomography revealed a left adrenal mass measuring 25 × 15 mm, and the findings were different from the typical adrenocortical adenoma or pheochromocytoma. Although laboratory examinations of his blood samples indicated normal adrenal function, 24-hour urine specimens revealed high levels of 17-OHCS, 17-KS, and catecholamine. Both ¹³¹I-MIBG scintigraphy and phentolamine tests showed negative findings. The patient underwent a laparoscopic left adrenalectomy. The cut surface of the left adrenal gland weighing 21 g contained a white, solid mass measuring 25 × 15 × 20 mm within the adrenocortical tissue. Histologically, the tumor was composed of small tubules lined by eosinophilic tumor cells. The tumor cells were immunohistochemically positive for cytokeratins and calretinin, but negative for steroidogenic factor-1. Therefore, based on these findings, we diagnosed this tumor as an adrenal adenomatoid tumor. Histopathologically, the adrenal adenomatoid tumor may be difficult to distinguish from an adrenocortical adenoma, carcinoma, lymphangioma, hemangioma, angiosarcoma, or metastatic adenocarcinoma. Under these conditions, immunohistochemical examination is useful for definite diagnosis.