Hematopoietically Active Adrenal Myelolipoma Mimicking Breast Cancer Metastasis.

A 66-year old woman had a left breast mass. Biopsy showed invasive ductal carcinoma. A PET/CT scan demonstrated hypermetabolism in the left breast and atypical heterogeneously increased uptake throughout the skeleton as well as a minimally FDG-avid right adrenal myelolipoma. PET/CT 4 months later after 6 cycles of neoadjuvant chemotherapy demonstrated increased size and FDG avidity of this adrenal mass concerning for metastasis and uniformly increased skeletal FDG avidity. Biopsy demonstrated adrenal myelolipoma. The growth and increased FDG avidity of the adrenal myelolipoma were due to the action of colony-stimulating factors on the tumor's hematopoietic component.

Adrenal myelolipoma: a mingle of progenitor cells?

Adrenal myelolipoma (AML) is a rare benign tumour composed or mature haematopoietic tissue and fat. The tumour is functionally inert and is usually detected incidentally. Mainly introduced in case reports, the tumourigenesis of AML is poorly understood with 3 historical hypotheses seemingly unrelated to each other. Here we propose the tumourigenic pathway based on the novel findings on stem/progenitor cell and our preliminary data. We hypothesize the tumourigenesis as follows: the fat components are derived by the mesenchymal stem cells of stromal fat of adrenal cortex under certain stimuli. Mature adipocytes begin to accumulate and become inflammatory stimulating neighbouring adrenal cortex tissue to release possibly G-CSF to recruit circulating haematopoietic progenitors. During the tumour growth, haematopoietic cell in the central part acquire energy from burning the surrounding fat until they are fully differentiated and division stops. Lacking the ability to further grow, the central part undergoes necrosis and calcification whilst the peripheral part continues to slowly pile up newly derived adipocytes and haematopoietic progenitor cells. The necrosis or calcification of the tumour the inflammation persists and the tumour generates a self-growing signalling loop, entailing a continuous growth even without further stimuli. Our theory offers a logical explanation to the diverse phenomena identified on AML and unifies the historical theories. Future studies may focus on the stem/progenitor cell profiles of AML to confirm and supplement our hypothesis.

Mielolipomas adrenales bilaterales como hallazgo incidental / Bilateral adrenal myelolipomas as an incidental finding

Los mielolipomas son tumores benignos raros, no funcionantes, compuestos por tejido adiposo maduro y precursores hematopoyéticos que involucran principalmente a las glándulas adrenales aunque pueden presentarse en localizaciones extraadrenales. Las características clínicas son muy variables, con descripciones de mielolipomas gigantes, bilaterales, asociados a síndromes de hipersecreción hormonal o a sangrado retroperitoneal. Con el incremento de la utilización de técnicas de imagen abdominales en la práctica clínica habitual, se ha observado un aumento de detección de incidentalomas adrenales, entre los cuales pueden encontrarse en raras ocasiones mielolipomas. Se describe el caso de una presentación inusual de mielolipomas adrenales bilaterales asintomáticos como hallazgo incidental en radiografías convencionales de abdomen, junto con un revisión de la literatura referida a estos tumores.

Myelolipomas are rare, non-functioning, benign tumors composed of mature fat tissue and myeloid hematopoietic precursors that involve mainly the adrenal glands and rarely other extra-adrenal tissues. The clinical features are heterogeneous and there are reports of giant and bilateral myelolipomas. Few tumors have been associated with endocrine dysfunction or retroperitoneal bleeding. With the development and wide-spread use of modern imaging techniques, this adrenal entity is sometimes found incidentally during radiology procedures for other reasons. We describe an unusual clinical presentation of asymptomatic bilateral myelolipomas incidentally discovered in abdominal X-Rays.

Fine-needle aspiration cytology of adrenal myelolipoma: case report and review of the literature.

Adrenal myelolipoma is a rare nonfunctioning tumor consisting histologically of an admixture of adipose tissue and extramedullary hemopoietic elements within the adrenal glands. Less than 300 cases have been reported in the literature and only 15 case reports have described cytological findings of this tumor obtained by fine-needle aspiration (FNA). We report a case of a 48-year-old male who had had anaplastic large cell carcinoma of the right lung. The left adrenal mass was encountered during a staging workup that led to a clinical suspicion of metastatic disease to the adrenal gland. FNA under computed tomography (CT) guidance was performed obtaining cytological material from which diagnosis of myelolipoma was made. The findings reemphasized an important role of FNA in investigation of adrenal mass. The literature on FNA cytology of adrenal myelolipoma is reviewed. Diagn. Cytopathol. 1999;21:409-412.

Myelolipoma of adrenal gland in association with occult malignancy--a case report.

Myelolipoma is an unusual lesion of adrenal gland in which ectopic marrow tissue is present. This case is being present because of its rarity.