Characterization of the clinical features of five families with hereditary primary cutaneous lichen amyloidosis and multiple endocrine neoplasia type 2.

The hereditary conditions of primary cutaneous lichen amyloidosis and multiple endocrine neoplasia type 2 (MEN 2) are rare clinical entities. The initial reports of two families in which the two conditions coincided have led to the identification of at least eight additional families with this clinical syndrome. In this report we describe the clinical features in five of these eight families. The salient feature in these five families is the presence of unilateral (46%) or bilateral (64%) pruritic and lichenoid skin lesions located over the upper portion of the back. Family members describe these skin lesions as intermittently intensely pruritic leading to scratching and excoriation of the upper back region. The presence of MEN 2 has been documented in 97% of family members with this skin lesion, the one exception being a child who is at risk for development of MEN 2A in whom the diagnosis has not yet been made. Of family members who have MEN 2A, 27% do not have an identifiable skin lesion, although the skin lesion developed in one patient two years after a curative thyroidectomy for medullary thyroid carcinoma (MTC). Four of the five families have members with pheochromocytoma; one with five affected members has only MTC. The finding of this clinical syndrome in geographically diverse portions of the world and the lack of overlap with MEN 2A without the skin lesion suggest it is a distinct clinical variant of MEN 2A.

Familial cutaneous lichen amyloidosis in association with multiple endocrine neoplasia type 2A: a new variant.

Multiple endocrine neoplasia type 2A (MEN 2A) is a rare hereditary disease transmitted in families as an autosomal dominant trait. We have identified a family in which the expression of a rare autosomal dominant form of cutaneous lichen amyloidosis appears to cosegregate with MEN 2A. In this family the skin lesion presented as multiple infiltrated papules overlying well demarcated plaques over the scapular area (right or left). Immunohistochemical studies demonstrated amyloid which stained for keratin but not calcitonin. A total of 19 members were screened. Three members of the family have the characteristic skin lesion and MEN 2A; two additional members have MEN 2A but have not manifested observable skin changes of lichen amyloidosis. Another unrelated Italian family with a similar type of pruritic skin rash and MEN 2A has been reported recently. Although the initial skin biopsies were negative for amyloidosis, subsequent biopsy established the association of MEN 2A with amyloidosis in this family also. When these kindreds are combined, several conclusions can be drawn. First, the syndrome of cutaneous amyloidosis and MEN 2A appears to be a clearly defined autosomal dominant hereditary syndrome. Whether this syndrome can be linked to chromosome 10 is not yet known. Second, the dermal amyloid appears to be caused by deposition of keratin-like peptides rather than calcitonin-like peptides. Third, we believe that patients with the hereditary form of cutaneous amyloid should be screened for medullary thyroid carcinoma to determine the true frequency of this syndrome.

Voluntary modification of the rotatory induced vestibulo-ocular reflex by fixating imaginary targets.

Voluntary enhancement and suppression of the vestibulo-ocular reflex (VOR) was investigated in 12 normal subjects aged 23-74. Eye movements were recorded using DC electrooculography in response to two patterns of horizontal rotation: single-frequency sinusoids in the 0.05-0.8 Hz frequency range; and pseudorandom waveforms consisting of a sum of sinusoids in the 0.05-0.35 Hz range. Subjects were able to significantly alter the gain and phase of their VOR responses by fixating imaginary targets in both patterns of stimulation. The amount of VOR modification decreased as the frequency of stimulation increased but was not correlated with age. In the clinical setting, potential voluntary alteration of the VOR must be considered in judging the normality of a subject's responses.

Voluntary modification of the rotatory induced vestibulo-ocular reflex by fixating imaginary targets.

Voluntary enhancement and suppression of the vestibulo-ocular reflex (VOR) was investigated in 12 normal subjects aged 23-74. Eye movements were recorded using DC electro-oculography in response to two patterns of horizontal rotation: (1) single-frequency sinusoids in the 0.05-0.8 Hz frequency range; and (2) pseudorandom waveforms consisting of a sum of sinusoids in the 0.05-0.35 Hz range. Subjects were able to significantly alter the gain and phase of their VOR responses by fixating imaginary targets in both patterns of stimulation. The amount of VOR modification decreased as the frequency of stimulation increased but was not correlated with age. In the clinical setting, potential voluntary alteration of the VOR must be considered in judging the normality of a subject's responses.