Cystic Pheochromocytoma Discovered as an Adrenal Incidentaloma

Abstract

Cystic pheochromocytomas are uncommon. Patients with cystic pheochromocytomas are more likely to be asymptomatic and to have a negative biochemical evaluation than those with classic solid tumors, which may lead to misdiagnosis. We describe herein a case of cystic pheochromocytoma that was discovered as an adrenal incidentaloma. The patient did not have any major symptoms, apart from occasional mild headaches and palpitations at night. Pheochromocytomas should be considered in the differential diagnosis of cystic adrenal lesions.

Characterization of Atypical Pheochromocytomas with Correlative MRI and Planar/Hybrid Radionuclide Imaging: A Preliminary Study

“…However, according to the specific mechanisms of MIBG and FDG tissue concentration, residual MIBG uptake allows the characterization and tumor diagnosis of pheos, while residual FDG accumulation generically reflects the presence of viable solid component of such tumor lesions. Similar findings have been previously reported either with iodine-123 MIBG single photon emission tomography (SPECT) integrated with CT [15][16][17]21] or with FDG hybrid imaging [13]. Therefore, according to our experience the radionuclide imaging features of such atypical pheos should be rationalized in clinical practice.…”

“…However, atypical pheos have been described with different imaging characteristics compared to the typical appearance of such tumor [2,[11][12][13][14][15][16][17][18][19]. In particular, these atypical lesions may be misdiagnosed since occur more frequently in asymptomatic patients without biochemical abnormalities compared to typical solid tumors [18].…”

“…MRI signal intensity heterogeneity has been reported reflecting tumor changes in atypical pheos [11]; of note, tumor cystic degeneration has been classified as total, predominant or partial with different imaging findings [15]. In addition, MIBG scintigraphy has been described to be useful in this type of pheo in some case reports showing increased tracer uptake confined only to the solid viable peripheral portion of tumors [15][16][17]. Similarly, MIBG uptake has been reported in a case of cystic malignant pheo with liver infiltration demonstrating also the efficacy of iodine-131 MIBG therapy in such patient who had excellent clinical and imaging responses to the radioactive treatment [21].…”

“…Raja et al [15] described several atypical patterns of pheos consisting of cystic change, hemorrhage, intense contrast enhancement, calcifications and intracellular lipid component. Similarly, MIBG scintigraphy has been described to be useful in atypical pheo showing increased tracer uptake only in the solid viable peripheral portion of tumors [15][16][17]. For these reasons, the discovery of these atypical pheos is not easy in clinical practice, often resulting in delayed diagnostic and therapeutic management with clinical consequences because of excessive catecholamine production [1,18].…”

Unusual Presentations of Adrenal Masses

“…CT often reveals a thick walled cystic lesion with presence or absence of septa within the adrenal mass, and persistent wall enhancement after contrast administration [115]. Surgical excision is the most definitive treatment of pheochromocytomas regardless of whether the tumor is cystic or not [117]. It is essential to consider this diagnosis in the differential as normotensive patients with unsuspected cystic pheochromocytoma have been reported to have intraoperative hypertensive crises during surgical excision [118].…”