The natural history and treatment of adrenal myelolipoma. J Urol. 1997;157:1213-1216. [PMID: 9120904 DOI: 10.1097/00005392-199704000-00006]

Spontaneous rupture of adrenal myelolipoma as a cause of acute flank pain: A case report

BACKGROUND

Adrenal myelolipoma is a rare, benign, non-functioning mass that occurs in the adrenal gland. It is composed of an admixture of hematopoietic elements and mature adipose tissue, similar to bone marrow. Even at large sizes, adrenal myelolipomas are usually asymptomatic and often incidentally found by ultrasonography or computed tomography (CT) scan. This paper describes an unusual case of adrenal myelolipoma presenting as flank pain.

CASE SUMMARY

A 50-year-old male with severe right flank pain underwent a CT scan revealing a huge mass extending into the suprarenal space. The mass showed a fat component with retroperitoneal hemorrhage. The tumor was treated laparoscopically, and pathologic examination revealed features of myelolipoma originating from the adrenal gland.

CONCLUSION

Adrenal myelolipomas are generally asymptomatic and can be treated conservatively. However, rupture and hemorrhage of the tumor can cause symptoms requiring surgical removal.

Presentation and therapy of myelolipoma

BACKGROUND

Adrenal myelolipoma is a rare and benign, hormonally inactive tumor frequently discovered incidentally. Because of the increasing rate of detection of adrenal myelolipoma, use of the correct diagnostic examination and treatment, with respect to surgical excision or regular controls, is continually gaining importance. We report herein on the largest series of surgically treated patients with adrenal myelolipoma from a single institute.

METHODS

The clinical charts of 12 patients who underwent adrenal surgery for myelolipoma were reviewed. Follow up was carried out by means of re-examination or by personal contact with the primary physician. It was possible to perform a re-examination on eight of the 12 patients 6.9 years after the operation: one patient had died 5.2 years after surgery.

RESULTS

Diagnosis of adrenal myelolipoma was made incidentally in seven patients, and during examination for reasons of unspecific abdominal or flank pain in five patients. A transabdominal approach was taken in five patients, a subcostal approach was taken in three patients and a translumbal approach was taken in four patients. At the follow up, all formerly symptomatic patients were free of symptoms. No recurrence could be seen; however, in one patient a contralateral adrenal myelolipoma had developed.

CONCLUSIONS

Symptomatic tumors, growing tumors or tumors larger than 10 cm should be excised surgically by means of an endoscopic or conventional approach, depending on the size. Surgical indication should not be liberalized by the introduction of more gentle operative techniques such as the translumbal or the endoscopic approach. A close follow up should be maintained in the case of patients free of symptoms, and for those with a definite diagnosis from imaging procedures.

Case of combined adrenal cortical adenoma and myelolipoma

We report a case of myelolipoma 10 mm in size within a functional cortical adenoma that was 33 x 22 x 17 mm in size. A 29-year-old woman was referred to hospital for transient hypertension. A right adrenal tumor was detected by computed tomography (CT) scan and magnetic resonance imaging (MRI). Her cortisol levels indicated a loss of the normal diurnal pattern, and urinary 17-hydroxycorticosteroids was elevated. She underwent a right adrenalectomy under the diagnosis of adrenal adenoma with Cushing's syndrome. The tumor was fairly well encapsulated by a thin layer of connective tissue. The major tumor portion was composed of two distinct cell types, clear cells and eosinophilic cells, arranged in an alveolar structure. These findings were representative of cortical adenoma. The adrenal cortical adenoma centrally included well-demarcated adipose tissue admixed with scattered islands of myelopoietic elements: erythroblasts, myeloid cell series and lymphocytic cells, which was eventually recognized as myelolipoma. Recently, adrenal myelolipoma has commonly been found because of the ease of detecting it as an incidentaloma by CT scan or MRI. However, the present adrenal myelolipoma case is uncommon because it is combined with a functioning cortical adenoma. Only six similar cases have previously been reported in English and Japanese publications. Furthermore, in the present case, the myelolipoma formed a tumor nodule, and to our knowledge, this is the first reported case of a radiographically recognizable tumor nodule. We discuss the etiology of myelolipoma and suggest that myelolipoma can develop in the course of endocrine hyperfunction.

Adrenal myelolipoma associated with adenoma

The association of an adrenal myelolipoma with a non-functioning adenoma is very rare. Herein, we report on such a case in an asymptomatic 64-year-old woman. To the best of our knowledge, there is only one other case of non-functioning adrenocortical adenoma associated with myelolipoma in the same gland. Furthermore, only two other adenomas (mineral corticoids and corticosteroid producing tumors) associated with myelolipomas have been reported, and both myelolipomas were less than 1 cm in size. In conclusion, the 8.5 cm myelolipoma in our case is the largest compared with the three previously reported ones.