Carcinoid syndrome

To the Editor

We read with interest the article of Rodriguez et al (March 2002), (1) in which they pointed out the importance of [sup.111]Indiethylenetriamine pentaacetic acid pentetreotide (OctreoScan; Mallinckrodt-Tyco; St. Louis, MO) scintigraphy in the preoperative diagnosis and intraoperative management of bronchial carcinoid. In 1997, we (2) published our preliminary results about our experience with OctreoScan in the preoperative diagnosis and postoperative follow-up of neuroendocrine and nonneuroendocrine tumors of the lung, OctreoScan is effective in detecting both primary neuroendocrine bronchial tumors and their mediastinal metastases with higher accuracy than thoracic CT scan. Positive scintigraphy results in nonneuroendocrine lung tumors (especially in undifferentiated large cell carcinomas) are probably due to the presence of activated lymphocytes surrounding the surface of the tumor. (2) We demonstrated how OctreoScan was effective in the diagnosis of liver metastases of resected atypical carcinoid with carcinoid syndrome (3); a positive OctreoScan result can, in addition, influence medical therapy with octreotide or lanreotide (two current generations of somatostatin analogs) because of the expression of the tumor tissue receptors for somatostatin. (3)

The authors used OctreoScan to obtain a preoperative diagnosis of neuroendocrine lung tumor, (1) and they performed a fight thoracotomy with a wedge resection of the lower and the middle lobes, guided by intraoperative octreotide scintigraphy. (1) They did not perform an anatomic resection or a systemic mediastinal lymphadenectomy. (1) Further, no information about the definitive histologic type of the resected bronchial carcinoid, clinical staging, and adjuvant therapy is present in the article.

It is well known that bronchial carcinoids are a part of the spectrum of neuroendocrine tumors of the lung (4); they are low-grade malignant tumors, which may be locally invasive or may spread to mediastinal lymph nodes, or distantly. (5) Mediastinal and distant metastases are more frequent in the atypical form. (5,6) Thus, preoperative diagnosis is mandatory inselecting the extent of surgical resection of the tumor. For a large neoplastic lesion such as this (6.5 cm in size), bronchoscopy or fine-needle aspiration biopsy is usually effective. The authors describe a nondiagnostic bronchoscopy, but they did not perform a transthoracic biopsy. The preoperative diagnosis of neuroendocrine tumor was obtained only by the positivity of the OctreoScan finding and the presence of high serotonin and 5-hydroxyindolacetic acid levels.

The current surgical management is influenced by the histologic type, the recurrence rate, and the survival patterns of neuroendocrine tumors, as described in literature (6-9); anatomic resections (lobectomy if pulmonary function test results are adequate, or segmentectomy in other cases) with systematic lymphadenectomy are mandatory, to reduce the risk of recurrence.

The authors performed a first wedge resection in the lower lobe, completed by another in the middle one, because of the presence of residual tumor in the scintigraphic intraoperative procedure. They did not perform an intraoperative histologic examination of a specimen of the tumor to confirm its neuroendocrine nature and to distinguish it from a small cell carcinoma. or a lymphadenectomy. (1)

We think that intraoperative OctreoScan might be effective in detecting micrometastases of neuroendocrine tumors, in lung tissue or in the mediastinum, but the surgeons must operate to achieve an oncologic radical resection of the lesion and avoid its recurrences. We suggest to the authors to use OctreoScan in the follow-up of these patients, because of its effectiveness in early detection of metastases or possible recurrences.

Correspondence to: Pier Luigi Filosso, MD, University of Torino, San Giovanni Battista Hospital, Department of Thoracic Surgery, Via Genova, 3 10126 Torino, Italy: e-mail: pierluigifilosso@tiscalinet.it

REFERENCES

(1) Rodriguez JA, Meyers MO, Jacome TH, et al, Intraoperative detection of a bronchial carcinoid with a radiolabeled somatostatin analog. Chest 2002; 121:985-988

(2) Oliaro A, Filosso PL, Bello M, et al. Use of [sup.111]In-DTPA-octreotide scintigraphy in the diagnosis of neuroendocrine and non-neuroendocrine tumors of the lung: preliminary results. J Cardiovasc Surg 1997; 38:313-315

(3) Filosso PL, Ruffini E, Rena O, et al. Long-term survival of atypical bronchial carcinoids with liver metastases, treated with octreotide. Eur J Cardiothorac Surg 2002; 21:91:3-917

(4) Travis WD, Colby TV, Corrin B, et al. Histological typing of lung and pleural tumours. 3rd ed. Berlin, Germany: Springer. 1999

(5) Filosso PL, Rena O, Donati G, et al. Bronchial carcinoid tumors: surgical management and long-term outcome. J Thorac Cardiovasc Surg 2002; 123:303-309

(6) Marty-Ane CH, Costes V, Pujol JL, et al. Carcinoid tumors of the lung: do atypical features require aggressive management? Ann Thorac Surg 1995; 59:78-83

(7) Travis W, Rush V, Flieder D, et al, Survival analysis of 200 pulmonary, neuroendocrine tumors with classification of criteria for atypical carcinoid and its separation from typical carcinoid. Am J Surg Pathol 1995; 22:934-944

(8) Ferguson MK, Landreneau RJ, Hazelrigg SR. et al. Long-term outcome after resection for bronchial carcinoid tumors. Eur J Cardiothorac Surg 2000; 18:156-161

(9) El Jamal M, Nicholson AG, Goldstraw P. The feasibility of conservative resection for carcinoid tumours: is pneumonectomy ever necessary for uncomplicated cases? Eur J Cardiothorac Surg 2000; 18:301-306

To the Editor:

Thanks to Filosso and associates for their comments on our article on bronchial carcinoid that appeared in CHEST (March 2002). (1) They refer to their report in 1997 in the Journal of Cardiovascular Surgery, (2) which we did not reference, as we acknowledged the work of Krenning and associates, (3) which antedated the work of Filosso and colleagues by a decade. Dr. Filosso points out that we did not perform an anatomic bilobectomy or a systematic mediastinal lymphadenectomy. It should be recalled that the patient had moderately severe mitral regurgitation with elevated pulmonary artery pressures. In addition, the intraoperative OctreoScan findings indicated no activity over the lymphatic drainage beds of the middle and lower lobes, and in our experience this is substantially more sensitive than the routine histologic examination of these nodes. (4) Though useful for staging, I am aware of no evidence suggesting that mediastinal lymphadenectomy affects survival in patients with lung cancer or lung carcinoid tumors. Although not reported in our article, the patient underwent mitral valve replacement after recovering from her thoracic procedure in order to correct her mitral insufficiency. We felt that the equivalent of a segmentectomy was the appropriate intraoperative management for this patient. A frozen section was, of course, obtained during that original operative procedure.

The patient has been observed at intervals of 6 months with total body OctreoScans, the findings of which have been negative for recurrent tumor to date.

Correspondence to: Lynn H. Harrison, MD, FCCP, LSU Health Sciences Center, 1542 Tulane Ave, New Orleans, LA 70112

REFERENCES

(1) Rodriguez JA, Meyers MO, Jacome TH, et al, Intraoperative detection of a bronchial carcinoid with a radiolabeled somatostatin analog. Chest 2002; 121:985-988

(2) Oliaro A, Filosso PL, Bello M, et al. Use of [sup.111]In-DTPA-octreotide scintigraphy in the diagnosis of neuroendocrine and non-neuroendocrine tumors of the lung: preliminary results. J Cardiovasc Surg 1997; 38:313-315

(3) Krenning EP, Bakker WH, Breeman WA, et al. Localization of endocrine-related tumours with a radioiodinated analogue of somatostatin. Lancet 1989; 1:242-244

(4) Woltering EA, Barrie R, O'Dorisio TM, et al. Detection of occult gastrinomas with [sup.125]I-labeled lanreotide and intraoperative gamma detection. Surgery 1994; 116:1139-1146

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