Cutaneous Mucinosis of Infancy: A Rare Congenital Case with Coexisting Progressive, Eruptive, and Spontaneously Involuting Lesions.

Cutaneous mucinosis in infancy is rare. We report an infant with multiple congenital papules distributed over the trunk, neck, and extremities. These papules were mainly dispersed, but they also coalesced into plaques. Histopathologic findings showed features of cutaneous mucinosis of infancy (CMI). Over 2 years of follow-up, we observed that the preexisting lesions on the lower back and left trunk progressively increased in size, and a few new scattered papules continued to appear, mainly on the trunk; several lesions spontaneously resolved with no further complications. CMI is considered to be a persistent cutaneous disorder, even though spontaneously regressing cases have rarely been reported. This case demonstrates the broad clinical spectrum of CMI, with progressive, eruptive, and spontaneously involuting lesions all present in the same patient. This condition should be considered in the differential diagnosis of congenital or infantile-onset papules and plaques, especially those yellowish in color.

Pagetoid dyskeratosis in dermatopathology.

Pagetoid dyskeratosis (PD) is an incidental pathologic finding that appears in several skin conditions. In an attempt to better understand PD and its incidence in dermatopathology, the authors have analyzed all skin biopsies performed over the period of 1 year in our Department of Dermatology and examined their clinical and dermatopathological variables. The criteria used for a keratinocyte to be considered a PD cell were: (1) a size larger than normal, (2) the presence of pycnotic nucleus, (3) a clear halo surrounding the nucleus, and (4) a pale eosinophilic cytoplasm. A total of 3565 biopsies were analyzed, PD cells being found in 80 cases (2.24%). Melanocytic nevi were the commonest skin lesions in which PD was observed, followed by soft fibromas, angiofibromas, and acrochordons. Most lesions were located on the head, neck, and trunk. Most cases displayed fewer than 15 PD cells per field. PD cells were normally located in the mid epidermis (frequently in clusters). The biopsies usually revealed indirect signs of rubbing, although PD cells were also found in places where rubbing was unlikely. Here, the authors report the largest series of PD analyzed to date, expanding our understanding of this striking pathological observation.

Follicular mucinosis associated with nonlymphoid skin conditions.

BACKGROUND: Follicular mucinosis coexisting with lymphoproliferative disorders has been thoroughly debated. However, it has been rarely reported in association with inflammatory disorders. METHODS: Thirteen cases have been retrieved, and those with cutaneous lymphoma or alopecia mucinosa were excluded. RESULTS: Follicular mucinosis was found in the setting of squamous cell carcinoma, seborrheic keratosis, simple prurigo, acne vulgaris, dextrometorphan-induced phototoxicity, polymorphous light eruption (2 cases), insect bite (2 cases), tick bite, discoid lupus erythematosus, drug-related vasculitis, and demodecidosis. Unexpectedly, our observations revealed a preponderating accumulation of mucin related to photo-exposed areas, sun-associated dermatoses, and histopathologic solar elastosis. The amount of mucin filling the follicles apparently correlated with the intensity of perifollicular inflammatory infiltrate, which was present in all cases. The concurrence of dermal interstitial mucin was found in 7 cases (54%). CONCLUSIONS: The concurrence of interstitial dermal mucinosis or the potential role of both ultraviolet radiation and the perifollicular inflammatory infiltrates in its pathogenesis deserves further investigations. Precise recognition and understanding of this distinctive, reactive histological pattern may prevent our patients from unnecessary diagnostic and therapeutic strategies.

Further insights in trichothiodistrophy: a clinical, microscopic, and ultrastructural study of 20 cases and literature review.

BACKGROUND: Trichothiodistrophy (TTD) is a rare autosomal recessive condition that is characterized by a specific congenital hair shaft dysplasia caused by deficiency of sulfur associated with a wide spectrum of multisystem abnormalities. In this article, we study clinical, microscopic, and ultrastructural findings of 20 patients with TTD with the aim to add further insights regarding to this rare condition. Additionally, analyses of our results are compared with those extracted from the literature in order to enhance its comprehensibility. MATERIALS AND METHODS: TWENTY CASES OF TTD WERE INCLUDED: 7 from Mexico and 14 from Spain. Clinical, microscopic, scanning electron microscopy (SEM) studies and X-ray microanalysis (XrMa) were carried out in all of them. Genetic studies were performed in all seven Mexican cases. Patients with xeroderma pigmentosum and xeroderma pigmentosum/TTD-complex were excluded. RESULTS: Cuticular changes and longitudinal crests of the hair shaft were demonstrated. These crests were irregular, disorganized, following the hair longest axis. Hair shaft sulfur deficiency was disposed discontinuously and intermittently rather than uniformly. This severe decrease of sulfur contents was located close to the trichoschisis areas. Only five patients did not show related disturbances. Micro-dolichocephaly was observed in five cases and represented the most frequent facial dysmorphism found. It is also remarkable that all patients with urologic malformations also combined diverse neurologic disorders. Moreover, three Mexican sisters demonstrated the coexistence of scarce pubic vellus hair, developmental delay, onychodystrophy, and maxillar/mandibullar hypoplasia. CONCLUSIONS: TTD phenotype has greatly varied from very subtle forms to severe alterations such as neurologic abnormalities, blindness, lamellar ichthyosis and gonadal malformations. Herein, a multisystem study should be performed mandatorily in patients diagnosed with TTD.

Photoletter to the editor: Localized pyoderma gangrenosum after interferon-alpha2b injections.

We present a male patient with polycythemia vera (PV) in whom pyoderma gangrenosum (PG) was induced by subcutaneous injections of interferon-α2beta (IFN-α2b).The patient presented with a 6 cm wide necrotic ulcer on the external aspect of his left thigh, which was surrounded by an erythematous and indurated plaque. He also had a simetrical but smaller 2 cm of size ulcer on the external aspect of the right thigh. Histopathological examination showed a massive perivascular and interstitial inflammatory infiltrate. It was vastly composed of neutrophils and secondary formation of interstitial neutrophilic microabscesses was also observed.To our knowledge only two cases of PG secondary to IFN-α2b injections have been reported, none of them in a patient with PV. Physicians should be aware of these IFN-α2b-related local adverse effects as they might become extremely severe. Immediate local discontinuation of drug administration is mandatory. In order to avoid these complications, alternating injection sites is highly advisable.

Gemcitabine-associated livedoid thrombotic microangiopathy with associated sclerema neonatorum-like microscopic changes.

Gemcitabine is a deoxycytidine analog antimetabolite that is now accepted as first-line treatment for advanced and metastatic pancreatic carcinoma. Gemcitabine-related thrombotic microangiopathy associated with systemic hemolytic-uremic syndrome or thrombotic thrombocytopenia purpura has rarely been described. Herein, we report a patient who developed a livedoid thrombotic microangiopathy with no signs of associated hemolytic-uremic syndrome. Cutaneous thrombotic microangiopathy occurred after the administration of his 17th cycle and a cumulative dose of 53.65 g/m(2) of gemcitabine. Some authors have suggested that this toxicity may be dose-related, and a 10th cycle or a cumulative dose of 9-56 g/m(2) have been proposed as the prothrombotic threshold. Interestingly, dermatopathologic findings were limited to the subcutis and they consisted of small-vessel occlusion by intravascular fibrin and leukocytes, vessel wall thickening and endothelial cell swelling. Surprisingly, we observed some structures arranged radially with needle-shaped clefts resembling those of sclerema neonatorum. Awareness of this potential cutaneous toxicity by dermatologists and dermatopathologists is extremely important.