Patients with ectopic ACTH syndrome might have a better prognosis in bronchopulmonary carcinoids with lymph node metastasis received radical surgery: a single-centre retrospective study in the last 22 years in China.

BACKGROUND: Bronchopulmonary carcinoids (BPCs) are rare malignancies but are known to be one of the most common causes of the ectopic adrenocorticotropic hormone (ACTH) syndrome. Surgery is the mainstay of therapy and one key question considering surgical treatment is the impact of local lymph node metastases. We sought to determine the risk factors and prognosis of LN metastases in resected carcinoid patients. METHODS: Data of 42 patients of BPCs with lymph node metastasis who received radical surgery in Peking Union Medical College Hospital (PUMCH) from Jan 2000 to Dec 2021 were retrospectively analysed. Overall survival (OS) and progression-free survival (PFS) were analyzed using Kaplan-Meier curves. Independent prognostic factors were assessed by COX hazard proportion model. RESULTS: It was indicated that in patients received radical surgery with local lymph node positive of BPCs, the 5-year OS and PFS rate was 74.5%, 68.3%, respectively. Multivariate Cox regression indicated that ectopic ACTH syndrome (EAS) could predict significantly to a better OS and PFS. In the subgroup analysis, the age, tumor size, Ki-67 index, histology and postoperative chemotherapy in patients with EAS had significantly differences with those without EAS. CONCLUSIONS: Our study certified R0 resection with lymphadenectomy was effective in patients with lymph nodal positive. The ectopic ACTH syndrome was a protective factor for a better prognosis, which could provide clear evidence for operations.

Pancreatic neuroendocrine tumor with ectopic adrenocorticotropic hormone syndrome: a case report and 5-year follow-up.

Pancreatic neuroendocrine tumors (P-NETs) secreting ectopic adrenocorticotropic hormones (ACTH) are rare and often delayed in diagnosis due to their atypical clinical characteristics. Here, we describe a case of P-NET in the pancreatic tail. The tumor had metastasized to the liver and secreted gastrin and ACTH. A 60-year-old female patient was diagnosed with gastrinoma in the pancreatic tail with liver metastases in 2015. After 3 months, the patient presented refractory hypokalemia and thyroid dysfunction. The final diagnosis was P-NET with ectopic ACTH syndrome (EAS). After cytoreductive surgery and the use of long-acting somatostatin analogs, plasma potassium levels and thyroid function were effectively corrected. Although Sandostatin LAR® Depot and proton pump inhibitors (PPIs) were used throughout the follow-up period, the tumor relapsed 4 years later. After aggressive treatment, including right hepatectomy, microwave coagulation of the left liver, and cholecystectomy, the tumor returned 4 months later. Finally, the patient underwent three hepatic artery embolizations and 12 courses of CAPTEM regimen chemotherapy. The markers of disease were almost maintained in the normal ranges until now. We have followed up on this case for more than 5 years. A timely and comprehensive examination of hormones and immunohistochemistry is essential. The prognosis of P-NET is poor. Regular long-term follow-up and the application of combined therapies are helpful to control the disease and improve the prognosis.

Single-cell transcriptome analysis identifies a unique tumor cell type producing multiple hormones in ectopic ACTH and CRH secreting pheochromocytoma.

Ectopic Cushing's syndrome due to ectopic ACTH&CRH-secreting by pheochromocytoma is extremely rare and can be fatal if not properly diagnosed. It remains unclear whether a unique cell type is responsible for multiple hormones secreting. In this work, we performed single-cell RNA sequencing to three different anatomic tumor tissues and one peritumoral tissue based on a rare case with ectopic ACTH&CRH-secreting pheochromocytoma. And in addition to that, three adrenal tumor specimens from common pheochromocytoma and adrenocortical adenomas were also involved in the comparison of tumor cellular heterogeneity. A total of 16 cell types in the tumor microenvironment were identified by unbiased cell clustering of single-cell transcriptomic profiles from all specimens. Notably, we identified a novel multi-functionally chromaffin-like cell type with high expression of both POMC (the precursor of ACTH) and CRH, called ACTH+&CRH + pheochromocyte. We hypothesized that the molecular mechanism of the rare case harbor Cushing's syndrome is due to the identified novel tumor cell type, that is, the secretion of ACTH had a direct effect on the adrenal gland to produce cortisol, while the secretion of CRH can indirectly stimulate the secretion of ACTH from the anterior pituitary. Besides, a new potential marker (GAL) co-expressed with ACTH and CRH might be involved in the regulation of ACTH secretion. The immunohistochemistry results confirmed its multi-functionally chromaffin-like properties with positive staining for CRH, POMC, ACTH, GAL, TH, and CgA. Our findings also proved to some extent the heterogeneity of endothelial and immune microenvironment in different adrenal tumor subtypes.

Differences in outcomes of bilateral adrenalectomy in patients with ectopic ACTH producing tumor of known and unknown origin.

BACKGROUND: Endogenous Cushing syndrome (CS) can be caused by ectopic corticotropin-producing tumors of known (EK) and unknown origin (EU). Bilateral adrenalectomy (BA) can be used as definite treatment of hypercortisolism in such cases. This study compared patients undergoing BA for CS secondary to EK vs EU. METHODS: Retrospective review (1995-2017) of patients undergoing BA due to EK or EU. We analyzed demographic characteristics, laboratory values, intraoperative variables, surgical outcomes, and survival. RESULTS: 48 patients (26 EU, 22 EK) were identified. Serum cortisol and ACTH concentrations were similar. 92% of BA for EU were performed minimally invasively vs 77% for EK, P = 0.22. Complications occurred in 19% of EU and 4.5% EK, P = 0.2. Mean survival was 4.3 years for EU and 4.0 years for EK without difference in all-cause mortality P = 0.63. CONCLUSION: BA cure rate was 100% for CS in EU and EK. Morbidity, long term and all-cause mortality differences were not statistically significant between EK and EU.

High Molecular Weight ACTH-Precursor Presence in a Metastatic Pancreatic Neuroendocrine Tumor Causing Severe Ectopic Cushing's Syndrome: A Case Report.

Ectopic ACTH-secretion causing Cushing's syndrome is unusual and its diagnosis is frequently challenging. The presence of high-molecular-weight precursors throughout pro-opiomelanocortin (POMC) translation by these tumors is often not reported. We present the case of a 49-year-old woman with a 3-month history of proximal muscular weakness, skin pigmentation, and weight loss. Upon initial evaluation, she had a full moon face, hirsutism, and a buffalo hump. Laboratory workup showed hyperglycemia, hypokalemia and metabolic alkalosis. ACTH, plasma cortisol, and urinary free cortisol levels were quite elevated. Serum cortisol levels were not suppressed on dexamethasone suppression testing. An octreo-SPECT scan showed enhanced nucleotide uptake in the liver and pancreas. Transendoscopic ultrasound-guided biopsy confirmed the diagnosis of a pancreatic ACTH-secreting neuroendocrine tumor (NET). Surgical excision of both pancreatic and liver lesions was carried out. Western blot analysis of the tumor and metastases revealed the presence of a high-molecular-weight precursor possibly POMC (at 30 kDa) but not ACTH (normally 4.5 kDa). ACTH-precursor secretion is more frequent in ectopic ACTH-secreting tumors compared with other causes of Cushing's syndrome. Hence, the measurement of such ACTH precursors warrants further evaluation, especially in the context of ACTH-dependent hypercortisolism.

The Clinical Features and Molecular Mechanisms of ACTH-secreting Pancreatic Neuroendocrine Tumors.

OBJECTIVE: Pancreatic neuroendocrine tumors (pNETs) causing ectopic adrenal corticotropic hormone (ACTH) syndrome (EAS) are rare and aggressive with little known information. We aimed to elucidate the clinical features and molecular mechanisms of pNETs with EAS by methylation analysis. METHODS: Seven patients with ectopic ACTH-secreting pNETs who were diagnosed at Shanghai Clinical Endocrine and Metabolic Diseases Center and Pancreatic Disease Center in Ruijin Hospital between 2001 and 2019 were enrolled. Twenty patients with ectopic ACTH-secreting thymic neuroendocrine tumors (TNETs) and 7 with nonfunctional pNETs (nf-pNETs) were also enrolled as controls. We collected clinical data and measured POMC promoter CpG methylation. RESULTS: All 7 patients had elevated ACTH and urinary free cortisol (UFC) levels with positive ACTH staining in the pancreas and were diagnosed with ectopic ACTH-secreting pNET. Of the 7 patients, 6 underwent surgery and 1 underwent transarterial embolization (TAE). Two patients were free of disease after surgery; 2 died within 90 days after surgery; and 3 had metastases and died within 1 year. Compared with ACTH-secreting TNETs, ACTH-secreting pNETs had similar clinical and biochemical features but a significantly poorer prognosis. POMC promoter CpG methylation was significantly lower in ACTH-secreting pNETs than in nf-pNETs and normal pancreas. CONCLUSIONS: ACTH-secreting pNETs are aggressive and fatal. Surgery is definitively curative for patients with resectable primary tumors without metastasis. Pro-opiomelanocortin (POMC) promoter hypomethylation caused pNETs to produce ACTH. This study further supplements the genetic features of ACTH-secreting NETs.

Radiologically defined lipid-poor adrenal adenomas: histopathological characteristics.

BACKGROUND: Adrenal lipid-poor adenomas (LPA) are defined by high unenhanced density (≥ 10 HU), and absolute and relative contrast medium washout > 60% and > 40%, respectively, at computerized tomography (CT). To date, no thorough histopathological characterization has been performed in those frequent lesions (one-third of adrenal adenomas). Our aim was to analyze the histopathological characteristics of adrenal LPA. METHODS: Patients with LPA (n = 57) were selected among consecutive subjects referred for an adrenal incidentaloma or ACTH-independent Cushing syndrome. FluoroDeoxyGlucose-Positron Emission Tomography (FDG-PET) was performed in 37 patients. In patients treated by adrenalectomy (n = 17), Weiss score and Lin-Weiss-Bisceglia score (in tumors composed entirely or predominantly of oncocytes) were calculated. RESULTS: Radiological parameters did not differ among patients with ACTH-independent Cushing syndrome (n = 6) and those with adrenal incidentalomas associated with primary aldosteronism (n = 2), autonomous cortisol secretion (n = 14), or non-functioning (n = 35). Patients treated by adrenalectomy had larger tumors (28.9 ± 11.2 vs 17.3 ± 8.4 mm, P < 0.001), higher CT unenhanced density (29.1 ± 11.0 vs 23.1 ± 9.0 HU, P = 0.043), and FDG-PET adrenal uptake (9.0 ± 6.4 vs 4.4 ± 2.3 SUV, P = 0.003) than non-operated ones. Oncocytic features > 75% of the tumor were detected in 12/17 cases (70.6%). Five of those showed borderline-malignant histopathological characteristics by Lin-Weiss-Bisceglia score. Among remaining non-oncocytic tumors, 1/5 had a Weiss score ≥ 3. Overall, 6/17 tumors (35.3%) had borderline-malignant potential. Radiological parameters were similar between patients with benign and borderline-malignant tumors. CONCLUSIONS: Adrenal LPA are a heterogeneous group of tumors, mostly composed of oncocytomas. Up to 1/3 of those tumors may have a borderline-malignant potential at histopathology.

Multiple hormone secretion may indicate worse prognosis in patients with ectopic Cushing's syndrome.

PURPOSE: Ectopic Cushing's syndrome (ECS) caused by an ACTH secreting neuroendocrine neoplasm (NEN) is a rare and challenging condition. We aimed to detect predictive and prognostic parameters for ECS patients identified from a retrospective, comprehensive cohort of NENs treated at a tertiary referral center. METHODS: Medical records of 886 patients with NENs were reviewed. We identified 51 patients with ECS (33 females/18 men); mean age 52 ± 15 years (SD). Clinical parameters including symptoms, biochemical markers, and survival were extracted and further analyzed. RESULTS: The primary tumor was located in the thorax (n = 28) or pancreas (n = 15) or was of unknown primary origin (n = 8). In 30 patients, tumor and ECS were diagnosed simultaneously. In 12 patients, the NEN diagnosis preceded ECS development, with a median time of 43.5 months (range: 9-96), and 10 of these showed radiological tumor progression at ECS diagnosis. Twenty-one patients had multiple hormone secretion, which correlated with shorter overall survival (OS), p = 0.012 (HR 2.4 (95% CI 1.2-4.9)), as did high morning cortisol, p = 0.037 (HR 2.3 (1.0-5.2)), higher tumor grade, p = 0.044 (HR 2.3 (1.0-5.1)), and diabetes, p = 0.050 (HR 2.4 (1.0-6.0)). CONCLUSIONS: Multiple hormone secretion, high morning cortisol, higher tumor grade, and diabetes were correlated with shorter OS. Development of ECS in patients with a non-functioning NEN may indicate tumor progression. Multiple hormone secretion should be considered as a bad prognostic sign in ECS patients and should lead to intensified clinical management.

Ectopic ACTH Syndrome in a Child With Abdominal Ewing Sarcoma: A Rare Paraneoplastic Phenomenon.

Ectopic adrenocorticotropic hormone syndrome is a paraneoplastic phenomenon rarely seen in pediatrics and rarely described in Ewing sarcoma. We report a 15-year-old boy with abdominal Ewing sarcoma and clinical and laboratory findings of ectopic adrenocorticotropic hormone syndrome that promptly resolved with treatment of the tumor.

Intestinal Perforation in ACTH-Dependent Cushing's Syndrome.

Previous studies have linked systemic glucocorticoid use with intestinal perforation. However, the association between intestinal perforation and endogenous hypercortisolism has not been well described, with only 14 previously published case reports. In this study, we investigated if intestinal perforation occurred more frequently in patients with ectopic ACTH syndrome and in those with a greater than 10-fold elevation of 24-hour urinary free cortisol level. Of 110 patients with ACTH-dependent Cushing's syndrome followed in two clinics in Canada, six cases with intestinal perforation were identified over 15 years. Age of patients ranged from 52 to 72, five females and one male, four with Cushing's disease and two with ectopic ACTH production, one from a pancreatic neuroendocrine tumor and one from medullary carcinoma of the thyroid. Five had diverticular perforation and one had intestinal perforation from a stercoral ulcer. All cases had their lower intestinal perforation when the cortisol production was high, and one patient had diverticular perforation 15 months prior to the diagnosis of Cushing's disease. As in previously reported cases, most had hypokalemia and abdominal pain with minimal or no peritoneal symptoms and this occurred during the active phase of Cushing's syndrome. Whereas all previously reported cases occurred in patients with 24-hour urinary free cortisol levels greater than 10-fold the upper limit of normal when measured and 11 of 14 patients had ectopic ACTH production, only one of our patients had this degree of hypercortisolism and four of our six patients had Cushing's disease. Similar to exogenous steroid use, patients with endogenous hypercortisolism also have a higher risk of intestinal, in particular diverticular, perforation and should be monitored closely for its occurrence with a low threshold for investigation and surgical intervention. Elective colonoscopy probably should be deferred until Cushing's syndrome is under control.

Molecular analysis and literature-based hypothesis of an immunonegative prostate small cell carcinoma causing ectopic ACTH syndrome.

Ectopic ACTH syndrome (EAS) due to a prostate small cell carcinoma (SCC) is very rare with only 26 cases reported to date and has a poor prognosis. We here describe another case of this disorder that was clinically typical based on prior reports as it showed hypercortisolemia and severe hypokalemia with multiple metastasis. However, our current case of prostate SCC causing EAS is the first to display negative immunostaining for ACTH despite detectable POMC mRNA expression in the primary lesion. ACTH immunonegativity is thought to be associated with a more aggressive disease course and a poorer prognosis although there are few studies of the underlying mechanisms. We explored two possibilities for this finding in our current patient: aberrant POMC processing prevented immunodetection with an anti-ACTH antibody; and the ACTH content per cell was below the threshold for immunodetection due to its rapid secretion or low synthesis. The aberrant processing theory was thought to be less likely because of immunonegative findings even using anti-POMC/ACTH antibodies. As the plasma ACTH levels in our patient were comparable with those reported for previous immunopositive prostate EAS cases, we speculated that the depletion of ACTH may be caused not only by rapid secretion but also by low production levels as a sign of de-differentiation. De-differentiation may therefore explain the mechanism underlying the negative correlation between immunoreactivity for ACTH in EAS and disease aggressiveness. We believe that our present findings will be of use in future prospective studies aimed at confirming the mechanism of immunonegativity.

A case of ectopic ACTH syndrome due to DDAVP-sensitive but V1b receptor-negative bronchial typical carcinoid with lymphatic metastasis and plasma ProGRP elevation.

Ectopic ACTH syndrome (EAS) is a potentially fatal endocrine disease that results from a variety of neuroendocrine tumors (NETs), such as small cell lung cancer (SCLC) and bronchial typical carcinoid. Typical carcinoid is usually slow growing, not associated with plasma progastrin releasing peptide (ProGRP) elevation. Here, we report a 47-year-old female smoker with progressive typical carcinoid and plasma ProGRP elevation. Several types of Cushingoid features were found on physical examination. In addition, laboratory examination showed elevated plasma ACTH and serum cortisol levels. These findings indicated ACTH-dependent Cushing's syndrome. Moreover, the serum cortisol level was not suppressed by overnight high-dose dexamethasone treatment, suggesting the presence of an extra-pituitary tumor. Contrast-enhanced brain MRI revealed no pituitary adenoma, which also supported the idea that EAS occurred in the present case. Strikingly, chest computed tomographic (CT) scan showed a single 18-mm peripheral nodule in the right middle lobe of the lung. Tumor marker analysis revealed an elevation in plasma ProGRP. These data suggested a possibility that SCLC secreted ACTH and caused EAS in this patient. Of note, the plasma ACTH level was increased (1.7 fold) in l-desamino-8-D-arginine vasopressin (DDAVP) test, also suggesting the specific clinical feature in this case. After additional imaging examinations, we performed surgical resection with the suspicion of limited SCLC. As a result, pathological examination revealed a vasopressin receptor Ib (V1b) receptor-negative bronchial typical carcinoid with ACTH production and mediastinal lymphatic metastasis. In summary, we present a case of EAS caused by progressive bronchial typical carcinoid with plasma ProGRP elevation. We propose a novel subtype of lung typical carcinoid.

Ectopic adrenocorticotropic hormone syndrome in a case of duodenal neuroendocrine tumor presenting with liver metastasis.

Ectopic adrenocorticotropic hormone (ACTH) syndrome is an uncommon disorder and comprises about 15% of all patients with Cushing's syndrome (CS). Duodenal carcinoids are rare, indolent tumors usually associated with a benign progression. We hereby report a rare case of CS resulting from ectopic ACTH secretion from a duodenal neuroendocrine tumor (NET) presenting with liver metastasis. A 37-year-old female presented with abdominal discomfort and dyspepsia of 1-month duration. Ultrasound abdomen suggested a well-defined hypoechoic lesion in the left lobe of the liver, suggestive of neoplasia. On clinical examination, she had Cushingoid features and persistent hypokalemia. Midnight ACTH and cortisol levels were grossly elevated at 1027 pg/ml (n < 46 pg/ml) and 87.56 µg/dl (n < 7.5 µg/ml), respectively. Both overnight and high-dose dexamethasone suppression test confirmed nonsuppressed cortisol levels - 86.04 and 84.42 µg/dl (n < 1.8 µg/ml), respectively. Magnetic resonance imaging brain showed a structurally normal pituitary gland. Computed tomography scan of the abdomen revealed hepatic lesion with bilateral adrenal enlargement. A diagnosis of ectopic ACTH-dependent CS was made. Intraoperatively, a duodenal lesion of 0.5 cm × 0.5 cm was identified alongside an 8 cm × 6 cm exophytic lesion in segment IV of the liver. Frozen section of the duodenal lesion was positive for NET. She underwent a Whipple's surgery, cholecystectomy, and left hepatic lobectomy. Postoperatively, she showed clinical and biochemical remission. Herewith, we report the third case of duodenal carcinoid tumor presenting as ectopic ACTH syndrome and the first with liver metastasis.

A rare case of ectopic ACTH syndrome originating from malignant renal paraganglioma

SUMMARY Ectopic adrenocorticotropic hormone (ACTH) syndrome is characterized by hypercortisolism due to the hypersecretion of a non-pituitary ACTH-secreting tumor leading to Cushing's syndrome. Only a few cases have been reported previously as causing ectopic ACTH related to paraganglioma. Herein, we present a case of Cushing's syndrome, in who was proved to be attributable to an ACTH-secreting renal malignant paraganglioma. A 40-year-old woman presented with a five-month history of newly diagnosed hypertension and diabetes, weakness, hyperpigmentation, oligomenorrhea, hirsutism, and acneiform lesions. She showed cushingoid features, including moon face, facial hirsutism, facial and truncal acne, hyperpigmentation, and severe muscle weakness of the limbs. She did not have other findings such as striae, supraclavicular fat accumulation, and buffalo hump. Laboratory examination showed the presence of hypopotasemia, hyperglycemia, hyperthyroidism, and leukocytosis. The serum levels of ACTH, cortisol, and urine-free cortisol were markedly elevated. Results of an overnight 2-mg dexamethasone suppression test included a basal serum cortisol of 61.1 mcg/dL (normal range: 4.6-22.8 mcg/dL) and a cortisol value of 46.1 mcg/dL after dexamethasone administration. There was no suppression found after 2-day 8-mg dexamethasone administration. Magnetic resonance imaging (MRI) of the pituitary gland indicated two microadenomas. An abdominal MRI scan revealed horseshoe kidney, bilateral adrenal hyperplasia, and masses with dimensions of 35 x 31 mm in the left kidney. Inferior petrosal sinus sampling showed no evidence of a central-to-peripheral gradient of ACTH. A positron emission tomography/computed tomography scan showed intense increased activity in the lower pole of the left kidney. Left adrenalectomy and left partial nephrectomy were performed. The resected tumor was diagnosed as the ACTH-secreting paraganglioma in the pathological examination, which was confirmed by immunohistochemical studies with chromogranin A, synaptophysin, and ACTH. Only a few cases of paragangliomas as a cause of ectopic ACTH syndrome have been reported. To our knowledge, this is the first case of renal paraganglioma resulting in Cushing's syndrome due to ectopic ACTH hypersecretion.

A rare case of ectopic ACTH syndrome originating from malignant renal paraganglioma.

Ectopic adrenocorticotropic hormone (ACTH) syndrome is characterized by hypercortisolism due to the hypersecretion of a non-pituitary ACTH-secreting tumor leading to Cushing's syndrome. Only a few cases have been reported previously as causing ectopic ACTH related to paraganglioma. Herein, we present a case of Cushing's syndrome, in who was proved to be attributable to an ACTH-secreting renal malignant paraganglioma. A 40-year-old woman presented with a five-month history of newly diagnosed hypertension and diabetes, weakness, hyperpigmentation, oligomenorrhea, hirsutism, and acneiform lesions. She showed cushingoid features, including moon face, facial hirsutism, facial and truncal acne, hyperpigmentation, and severe muscle weakness of the limbs. She did not have other findings such as striae, supraclavicular fat accumulation, and buffalo hump. Laboratory examination showed the presence of hypopotasemia, hyperglycemia, hyperthyroidism, and leukocytosis. The serum levels of ACTH, cortisol, and urine-free cortisol were markedly elevated. Results of an overnight 2-mg dexamethasone suppression test included a basal serum cortisol of 61.1 mcg/dL (normal range: 4.6-22.8 mcg/dL) and a cortisol value of 46.1 mcg/dL after dexamethasone administration. There was no suppression found after 2-day 8-mg dexamethasone administration. Magnetic resonance imaging (MRI) of the pituitary gland indicated two microadenomas. An abdominal MRI scan revealed horseshoe kidney, bilateral adrenal hyperplasia, and masses with dimensions of 35 x 31 mm in the left kidney. Inferior petrosal sinus sampling showed no evidence of a central-to-peripheral gradient of ACTH. A positron emission tomography/computed tomography scan showed intense increased activity in the lower pole of the left kidney. Left adrenalectomy and left partial nephrectomy were performed. The resected tumor was diagnosed as the ACTH-secreting paraganglioma in the pathological examination, which was confirmed by immunohistochemical studies with chromogranin A, synaptophysin, and ACTH. Only a few cases of paragangliomas as a cause of ectopic ACTH syndrome have been reported. To our knowledge, this is the first case of renal paraganglioma resulting in Cushing's syndrome due to ectopic ACTH hypersecretion.

Cutaneous manifestations of lung cancer.

Skin findings can serve as a clue to internal disease. In this article, cutaneous manifestations of underlying lung malignancy are reviewed. Paraneoplastic dermatoses are rare, but when recognized early, can lead to early diagnosis of an underlying neoplasm. Malignancy-associated dermatoses comprise a broad group of hyperproliferative and inflammatory disorders, disorders caused by tumor production of hormonal or metabolic factors, autoimmune connective tissue diseases, among others. In this review, paraneoplastic syndromes associated with lung malignancy are discussed, including ectopic ACTH syndrome, bronchial carcinoid variant syndrome, secondary hypertrophic osteoarthropathy/digital clubbing, erythema gyratum repens, malignant acanthosis nigricans, sign of Leser-Trélat, tripe palms, hypertrichosis lanuginosa, acrokeratosis paraneoplastica, and dermatomyositis.