According to the ‘developmental constraint hypothesis’ of comparative mammalian neuroanatomy, brain growth follows predictable allometric trends. Therefore, brain structures should scale to the entire brain in the same way across mammals. Evidence for a departure from this pattern for cerebellum volume has recently been reported among the anthropoid primates. One of the mammalian groups that has been neglected in tests of the ‘developmental constraint hypothesis’ is the cetaceans (dolphins, whales, and porpoises). Because many cetaceans possess relative brain sizes in the range of primates comparative tests of the ‘developmental constraint hypothesis’ across these two groups could help to delineate the parameters of this hypothesis. In this paper, we compare relative cerebellum volumes in two cetacean species, the bottlenose dolphin (Tursiops truncatus) and the common dolphin (Delphinus delphis), with published data from anthropoid primates. We found that relative cerebellum size is significantly greater in the two dolphin species than in any of the primates, including humans. These results suggest that there is possibly expansion of brain structures independent of strictly allometric processes.

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An 89-year-old man presented with a clinically cystic 4-mm papule on the left temple. The clinical impression was a benign cyst. Pathologic examination revealed a small, symmetric-appearing, well-circumscribed, dermal-based cystic lesion with markedly atypical-appearing clear to squamoid cells lining the cyst wall, consistent with carcinoma in situ involving the cyst. The cells showed abundant glycogen-containing cytoplasm (confirmed by Periodic acid Schiff stains with and without diastase), consistent with tricholemmal differentiation, and areas of tricholemmal/pilar-type keratinization (without a granular layer), consistent with tricholemmal carcinoma in situ, most likely arising in a tricholemmal/pilar cyst. Ki-67 and p53 immunohistochemical stains were strongly positive (with more than 20% of nuclei staining on Ki-67 and more than 80% on p53) in the cyst-lining cells, further supporting the interpretation of carcinoma in situ. Multiple deeper level sections were examined but did not show any evidence of an associated invasive carcinoma. Tricholemmal (pilar) cysts are common benign adnexal lesions and atypia/dysplasia or carcinoma in situ arising within them is exceedingly rare. Previously, only one case of a tricholemmal cyst with carcinoma in situ has been reported. That case was associated with an atypical fibroxanthoma. We report only the second case of tricholemmal carcinoma in situ, most likely involving a tricholemmal cyst, which was not associated with another tumor or evidence of invasive carcinoma.

A 51-year-old woman with a past medical history of type II diabetes mellitus and dyslipidemia presented to the Dermatology Department with pain, swelling, and crusting of the lips. This was accompanied by anal pain, odynophagia, and weight loss of 20 kg since the onset of symptoms. Previous evaluations by Head and Neck Surgery, Allergy, and Infectious Diseases Departments included lip biopsy, viral and bacterial cultures, and treatment with topical antifungals, an oral antiviral, topical and oral antibiotics, and topical steroids. The biopsy and culture studies did not reveal the etiology of her condition, and the treatments did not improve her symptoms.One year after onset of her mucosal lesions, the patient developed an abdominal eruption consisting of several tense vesicles and bullae on an erythematous base (Figure 1). She also had lip edema and crusting, oral erosions and ulcerations, and an anal fissure. Histologic examination revealed suprabasal acantholysis (Figure 2), the histologic hallmark of Pemphigus vulgaris (PV) that is essential for diagnosis.1 Furthermore, direct immunofluorescence showed intercellular staining with immunoglobulin G (IgG) and complement test C3, which was also consistent with PV.After biopsy, the patient was empirically started on methylprednisolone, 48 mg daily. After confirmation of her diagnosis, the patient was also started on mycophenolate mofetil, 500 mg twice daily. The methylprednisolone was later switched to prednisone, 80 mg daily, because of gastrointestinal intolerance. Owing to minimal response after 2 months of therapy, the patient received 2 rituximab infusions of 1000 mg, 2 weeks apart. There was noticeable improvement within 2 weeks of her first dose of rituximab. DISCUSSIONPV is an autoimmune disease with the average age of onset between 40 and 60 years of age. It is characterized by involvement of the oral mucosa, such as painful oral erosions that often precede painful, cutaneous flaccid vesicles and bullae.2 Involvement of the oral mucosa is usually accompanied by severe pain that can lead to weight loss and malnutrition. Although it is a rare disease, with incidence rates between 0.1 and 0.5 per 100,000 people per year, PV has the potential for lifethreatening complications, and treatment is always indicated at the time of disease onset.3 PV can be further subdivided into mucosal dominant type, presenting with mucosal lesions and minimal skin involvement; and mucocutaneous type, which presents with skin blisters and erosions along with mucous membrane lesions. IgG antibodies against desmoglein (Dsg) 1 and Dsg 3, cadherin-type cell-to-cell adhesion molecules in desmosomes, are believed to play a role in inducing vesicle and bullae formation in PV. 4 The dysfunction in Dsg 1 and Dsg 3 results in the loss of cell-to-cell adhesion in skin membranes and mucous membranes, respectively. ABSTRACTWe report a case of a 51-year-old woman with a history of type II diabetes mellitus and dyslipidemia presenting with pain, swelling, and crusting of the lips. One year aft...