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20. How to suspect MEN2A syndrome?

MTC is the most common and the earliest presenting manifestation of MEN2A

syndrome. The presence of diffuse or nodular goiter and recurrent diarrhea in a

euthyroid young individual (<35 years of age) should raise a suspicion of

MTC. Seventy percent of patients may have cervical lymph node metastasis

even at presentation. Therefore, MTC is an important differential diagnosis in a

young individual with goiter and cervical lymphadenopathy. Pheochromocytoma

usually follows MTC; however, it may be the initial presenting manifestation in

13–27 % of individuals. Young age of onset, milder symptoms, bilateral adrenal

lesions, and predominantly epinephrine-secreting tumor are the characteristic

features of MEN2A-associated pheochromocytoma compared to sporadic

pheochromocytoma. In addition, MEN2A-associated pheochromocytoma is

invariably benign. PHPT in MEN2A is usually mild and asymptomatic and

presents many years later after the diagnosis of MTC.

21. A 20-year-old male presented with nodular goiter and cervical lymphadenopa-
    thy. Thyroid function test was normal and FNAC from thyroid showed
    MTC. How to proceed further?

The index patient has MTC which may be sporadic or hereditary. Approximately

20 % of patients with MTC have either MEN2 or familial MTC (FMTC).

Therefore, every patient of MTC should be screened for familial syndromes.

The work up protocol for a patient with suspected MTC is depicted in the flow-

diagram given below (Fig. 11.4).

Thyroid Nodule

FNAC

MTC

Serum CT, CEA

USG neck

RET mutation

RET +ve

Pheochromycytoma

If present

Adrenalectomy

prior to TTx

If present

PTHx

during TTX

PHPT CT

<500pg/ml

TTx

±Lymphnode

dissection

±EBRT

Metastatic

work-up

CT

>500pg/ml

RET -ve

Fig. 11.4 Approach to a patient with suspected MTC

11 Multiple Endocrine Neoplasia