Myelolipoma

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Classification according to ICD-O-3
8870/0 Myelolipoma
ICD-O-3 first revision online

Myelolipomas are rare benign tumors or tumor-like lesions that are composed of mature adipose tissue and variable amounts of hematopoietic tissue and usually manifest in the area of ​​the adrenal gland . The term myelolipoma was coined in 1929 by the French pathologist Charles Oberling (1895-1960).

Epidemiology

In autopsy studies, myelolipomas were found in 0.08–0.4% of cases. Men and women are affected roughly equally. The age peak is in the 5th – 7th Decade of life.

etiology

The underlying causes of myelolipoma development are unknown. The possibility of metaplasia of reticuloendothelial cells of blood capillaries as a result of stimuli such as necrosis , infection or stress is discussed . Sometimes the tumor is also viewed as a site of extramedullary blood formation. Recent studies show that both the fat and the myeloid components are of monoclonal origin, so that the myelolipoma may be a real neoplasm . An association with congenital adrenal hyperplasia is also described in the literature .

pathology

Macroscopic picture of a myelolipoma.
Microscopic image of a myelolipoma with adrenal cells, fat cells, and myeloid cells.

Myelolipomas are yellow to brownish tumors a few millimeters to 30 cm in size, circumscribed but not encapsulated. They usually occur solitary and unilaterally in the area of ​​an adrenal gland, but are rarely found bilaterally and / or outside the adrenal gland (e.g. in the retroperitoneum , mediastinum , liver , in muscle fasciae). Microscopically, the tumor is made up of mature adipose tissue and myeloid cells. Occasionally, infarct areas, hemorrhages or osseous metaplasia are observed.

Symptoms

Myelolipoma of the left adrenal gland (arrows) on computed tomography . The arrowhead points to the normal right adrenal gland.
Myelolipoma on ultrasound.

The majority of myelolipomas are asymptomatic and are found by chance, for example during radiological examinations or an autopsy. Affected patients only occasionally report pain in the abdomen or flanks, especially with larger tumors. Endocrine disorders such as Cushing's , Conn's syndrome or congenital adrenal hyperplasia are rare .

therapy

Small, asymptomatic myelolipomas do not require therapy. Symptomatic tumors are treated by surgical removal of the adrenal gland.

forecast

The prognosis for myelolipomas is usually good. A malignant degeneration of the tumor has not yet been reported. A spontaneous or traumatic tumor rupture with subsequent bleeding can occur as a rare complication. Data on mortality in myelolipoma are not available due to the rarity of the lesion.

swell

  • Wegener: whole body computed tomography . Blackwell Wissenschaft, Berlin 1992, ISBN 3-89412-105-X .
  • Michael Federle: Abdomen: The 100 Top Diagnoses. Urban & Fischer Verlag, 2004, ISBN 3-437-23590-7 , pp. 319-321.
  • M. Goepel et al .: lipoma of the adrenal gland, case report and review of the literature. In: Urologist. 37, 1998, pp. 526-539.

Individual evidence

  1. ↑ a b c d e f g P. Ramchandani: Adrenal Myelolipoma. (February 15, 2007). (online on Medscape )
  2. ↑ a b C. DM Fletcher: Diagnostic Histopathology of Tumors. 3. Edition. Vol. 2. Churchill Livingstone, 2007.
  3. ↑ Oberling: Les formations myelolipomaleuses. In: Bull. Cancer. 1929; 18, p. 234.
  4. ^ A. McNicol: A diagnostic approach to adrenal cortical lesions. In: Endocr Pathol. (2008) 19, pp. 241-251. PMID 19089656
  5. ^ A. Reineke-Lüthge, F. Koschoreck, G. Klöppel: The molecular basis of persistent hyperinsulinemic hypoglycemia of infancy and its pathologic substrates. In: Virchows Arch. 2000 Jan; 436 (1), pp. 1-5. PMID 10664155

Web links

Commons : Myelolipoma  - Collection of pictures, videos and audio files