50. Where a diagnosis or recrudescence question is referred to a medical appeal tribunal that tribunal, upon determining the question referred—
(a)may proceed to determine any diagnosis or recrudescence question which arises in connection therewith and any disablement question which arises in consequence thereof and where a decision on any-such question has been given by an adjudicating medical authority, may confirm, reverse or vary that decision; and
(b)where it is determined that the disease is a recrudescence of an attack to which an earlier decision of an adjudicating medical authority>-or a medical appeal tribunal relates, may proceed to review that earlier decision under the provisions of section 45(4) of the Administration Act.