Solitary Brain Metastasis: A Rare Initial Presentation of Prostate Carcinoma.

Cerebral metastasis as an initial clinical presentation of prostate carcinoma is extremely rare. Usually, patients have widespread metastasis in the body before presenting with brain metastasis. In the absence of extensive metastasis, especially without bony metastasis, only brain metastasis is an unusual presentation of the disease. We report a case of a 59-years-old patient who presented with a lack of concentration and decreased vision. Magnetic resonance imaging (MRI) of the brain revealed a large right parietal-occipital space-occupying lesion. He underwent surgery and the pathological diagnosis of the tumor turned out to be metastatic prostate carcinoma. Further evaluation by a whole-body computed tomography (CT) scan revealed an enlarged prostate with no other metastatic deposit and a mildly raised level of prostate-specific antigen (PSA). It was possible for us to provide this patient with multi-modality treatment with the help of multidisciplinary tumor board meetings. Further studies addressing the biological as well as clinical characteristics of prostate carcinoma with this rare metastatic presentation will help us to define prognostic factors and therapeutic intervention and will help us to understand the basis of this unique presentation without bone metastasis.

Hidradenocarcinoma: Five Years of Local and Systemic Control of a Rare Sweat Gland Neoplasm with Nodal Metastasis.

Hidradenocarcinoma is a rare and locally aggressive tumor rendering a poor prognosis. Furthermore, very few cases present with nodal metastasis. Diagnosing such an entity, and then differentiating it from a benign counterpart, poses a great challenge to the clinicians. There are no established treatment guidelines for the management of this disease, particularly in patients with nodal involvement. We present a case of a young male who was diagnosed with hidradenocarcinoma of the scalp, along with a neck swelling. A thorough diagnostic evaluation was done with endoscopy, pathological, and radiological investigations. He was successfully treated with resection of the scalp lesion and right-sided neck dissection followed by adjuvant concurrent chemoradiation. He remains free of any local and distant disease after five years of regular follow-up.

Dynein light chain 8a of Toxoplasma gondii, a unique conoid-localized ß-strand-swapped homodimer, is required for an efficient parasite growth.

Dynein light chain 8 (DLC8) is a ubiquitous eukaryotic protein regulating diverse cellular functions. We show that the obligate intracellular parasite Toxoplasma gondii harbors 4 DLC8 proteins (TgDLC8a-d), of which only TgDLC8a clusters in the mainstream LC8 class. TgDLC8b-d proteins form a divergent and alveolate-specific clade. TgDLC8b-d proteins are largely cytosolic, whereas TgDLC8a resides in the conoid at the apical end of T. gondii. The apical location of TgDLC8a is also not shared by its nearly identical Eimeria (EtDLC8a), Plasmodium (PfDLC8), or human (HsDLC8) orthologs. Notwithstanding an exclusive conoid targeting, TgDLC8a exhibits a classical LC8 structure. It forms a homodimer by swapping of the ß strands that interact with the antiparallel ß' strands of the opposing monomers. The TgDLC8a dimer contains two identical binding grooves and appears to be adapted for multitarget recognition. By contrast, the previously reported PfDLC8 homodimer is shaped by binding of the ß strand with the parallel ß' strand and lacks such a distinct binding interface. Our comparisons suggest an unexpected structural and functional divergence of the two otherwise conserved proteins from apicomplexan parasites. Finally, we demonstrate that a phosphomimetic S88E mutation renders the TgDLC8a-S88E mutant monomeric and cytosolic in T. gondii, and its overexpression inhibits the parasite growth in human fibroblasts.