Incidental metastatic mediastinal atypical carcinoid in a patient with parathyroid adenoma: a case report.
BACKGROUND
Atypical carcinoid arising from the mediastinal tissue is a rare neuroendocrine tumor and an association with parathyroid adenoma is very unusual. We report an unusual case of atypical carcinoid of mediastinum with metastasis in a patient presenting with parathyroid adenoma, which is the first case to be reported from Pakistan.


METHODS
A 51-year-old Pakistani man was seen in postoperative intensive care after right parathyroidectomy and mediastinal mass resection for the management of postoperative hypocalcaemia. He had a background history of dyspnea. Examination was unremarkable. Preoperative laboratory evaluation revealed a calcium level of 12.7 mg/dl, phosphate of 1.9 mg/dl, serum albumin of 4.8 g/dl, alkaline phosphate of 94 U/L, and serum intact parathyroid hormone level 413.8 pg/ml. A technetium-99m sestamibi parathyroid scan showed right parathyroid increased tracer uptake. Further workup revealed a large mediastinal mass which was diagnosed as atypical carcinoid after Tru-Cut biopsy. He underwent right-sided parathyroidectomy and resection of the mediastinal mass. The histopathology confirmed it to be a parathyroid adenoma and atypical carcinoid tumor of his mediastinum with metastasis in his lymph node and parathyroid gland. Somatostatin receptor scintigraphy revealed a well-defined focus in his left hypochondriac region consistent with a somatostatin receptor scintigraphy-avid tumor. He was started on everolimus and planned for octreotide therapy.


CONCLUSIONS
We describe an incidental finding of atypical carcinoid of the mediastinum in a patient diagnosed as having parathyroid adenoma. Clinical manifestations of neuroendocrine syndromes are challenging. Some tumors cluster in a non-classic description with other common neoplasms. They rarely present in isolation, remain clinically silent, and need aggressive workup with the aid of imaging and histopathology.
Section of Endocrinology, Department of Medicine, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan. zareen.kiran@aku.edu.
Zareen
Z
Kiran
Section of Endocrinology, Department of Medicine, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Asma
A
Ahmed
Section of Endocrinology, Department of Medicine, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Owais
O
Rashid
Department of Histopathology, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Saira
S
Fatima
Department of Histopathology, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Faizan
F
Malik
Department of Cardiothoracic Surgery, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Saulat
S
Fatimi
Department of Ear, Nose & Throat, Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
Mubassher
M
Ikram
D000970:Antineoplastic Agents / Q000627:therapeutic use; D002276:Carcinoid Tumor / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D000068338:Everolimus / Q000627:therapeutic use; D006801:Humans; D006996:Hypocalcemia / Q000601:surgery*; D033162:Incidental Findings; D008297:Male; D008479:Mediastinal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D008482:Mediastinum / Q000473:pathology*; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D016105:Parathyroidectomy; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D000068338:Everolimus
Atypical carcinoid; Case report; Multiple endocrine neoplasia; Parathyroid neoplasms