Forme fruste

In medicine, a forme fruste (French, “crude, or unfinished, form”; pl., formes frustes) is an atypical or attenuated manifestation of a disease or syndrome, with the implications of incompleteness, partial presence or aborted state. The context is usually one of a well defined clinical or pathological entity, which the case at hand almost — but not quite — fits.

An opposite term in medicine, forme pleine — seldom used by English-speaking physicians — means the complete, or full-blown, form of a disease.

According to gastroenterologist William Haubrich:

A patient may exhibit sudden, intense, epigastric pain and a rigid abdomen. He is thought to have a perforated peptic ulcer. But at operation, only a penetrating ulcer is found, sealed off by adhesion to the omentum or anterior abdominal wall. Such a patient is said to have a forme fruste of acute free perforation as a complication of his peptic ulcer disease.

The Latin phrase frustra esse means "to be mistaken" or "to be confused". As a technical term in French, the cognate fruste has been used in two related ways. First, as an antiquarian’s term it refers to a coin, medal or ancient stone on which figures and characters can no longer be recognized due to wear. Secondly, it was employed in natural history to denote mollusk shells whose striations, grooves or tips were worn down. By extension, this sense could be applied to sculpture, pottery, or other objects of great antiquity.

It was in this sense of “indistinctness due to wear or through long use” that the great French internist Armand Trousseau (1801–67) first employed the term in connection with an obscured form of Graves' disease, which he described as a “…maladie dite fruste par l’absence du goitre et de l’exophthalmie” (“…disease said to be crude [i.e., indistinct] for its absence of goiter and exophthalmia”)

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