Sarcoidosis is a systemic granulomatous disorder of unknown etiology that can affect any organ in the body. It is characterized by the formation of non-caseating granulomas, which are clumps of inflammatory cells that cluster together in response to an unidentified antigen. The lungs and lymph nodes are most commonly involved. Here's a detailed explanation for each of the options:

1. Dry cough: This is a common symptom of pulmonary sarcoidosis. The cough is usually persistent and non-productive, meaning it does not bring up mucus or phlegm. The presence of a dry cough is not contradicted in the statement "All are true regarding Sarcoidosis except," so this option is not the correct answer.

2. Exertional dyspnoea: Shortness of breath on exertion can occur in individuals with pulmonary sarcoidosis due to the inflammation and granuloma formation in the lungs. This symptom can be a result of the impaired lung function and decreased lung capacity caused by the disease. Therefore, this is also a true statement regarding sarcoidosis.

3. Wheezing: Wheezing is a high-pitched whistling sound that occurs during breathing, typically heard when airways become narrowed or blocked. It can be a symptom of pulmonary sarcoidosis, particularly if the disease involves the bronchi and bronchioles, leading to bronchial obstruction and airflow limitation. However, it is not the primary symptom and may be less common than the other respiratory symptoms mentioned.

4. Hemoptysis: While hemoptysis, or coughing up blood, is not a hallmark symptom of sarcoidosis, it can occur in some cases, particularly when the granulomas are located in the lungs. It is usually mild and self-limited, but severe cases can lead to significant bleeding. This is a true statement regarding sarcoidosis, as it is a possible, although less common, respiratory symptom of the disease.

Since all the options (1, 2, and 4) are true regarding Sarcoidosis

Oncofoetal antigens are substances that are normally present in the developing fetus but are found in abnormally high quantities in the tissues of certain cancer cells. These antigens are proteins that can be used as markers for the detection of certain types of cancers. The presence of these antigens in cancer cells suggests that the tumor cells have partially reverted to a more primitive, embryonic stage of development.

Explanation for each option:

1. á-Fetoprotein (AFP): This is an oncofoetal antigen. It is a glycoprotein that is produced by the liver cells of the developing fetus. In adults, the production of AFP is usually very low. However, in cases of certain cancers such as hepatocellular carcinoma (primary liver cancer) and some types of testicular cancer, the tumor cells start producing AFP in large amounts. Therefore, high levels of AFP in the blood can be indicative of these cancers.

2. Carcinoembryonic antigen (CEA): CEA is another example of an oncofoetal antigen. It is a glycoprotein that is present in the gastrointestinal tract, pancreas, and sometimes in the respiratory and reproductive systems of a developing fetus. In adults, CEA levels are typically very low. However, in certain types of cancers, such as colorectal cancer, gastric cancer, and some forms of lung, pancreatic, and breast cancer, the tumor cells may start producing large amounts of CEA, which can be detected in the blood and used as a tumor marker for these malignancies.

3. A and B: Both α-fetoprotein and carcinoembryonic antigen are examples of oncofoetal antigens, so this option is correct.

Extensive cellulitis is most accurately described by the term "phlegmon

Phlegm is a thick, viscous substance produced by the respiratory tract, especially during a respiratory infection, which can be coughed up from the lungs or expelled from the nose. It is primarily composed of mucus, dead cells, and other substances.

Phlegmon is a term that is closely related to extensive cellulitis. It refers to a severe form of cellulitis where the infection has spread deeply into the subcutaneous tissues and is accompanied by significant inflammation, including the presence of pus and necrosis. Phlegmon is characterized by intense pain, swelling, redness, and warmth in the affected area. This condition often requires aggressive medical management, including intravenous antibiotics and surgical drainage if an abscess forms. It is an advanced and severe stage of cellulitis that can lead to systemic infection if not treated properly.

Nuclear cytoplasmic asynchrony refers to a condition where the nucleus and cytoplasm of a cell do not develop at the same rate. This can occur in various forms of anemia and other pathological conditions. Here's a detailed explanation of the concept and its relevance to the options provided:

1. Megaloblastic Anemia: Megaloblastic anemia is a type of anemia characterized by the presence of large, immature, nucleated red blood cells (megaloblasts) in the bone marrow and peripheral blood. This condition is primarily caused by a deficiency in vitamin B12 or folic acid, which are essential for DNA synthesis during cell division. The nucleus of the cells divides more slowly than the cytoplasm, leading to an asynchronous development and the formation of large, abnormal cells. In megaloblastic anemia, the nucleus is often large and hyperchromatic (darkly stained), while the cytoplasm is relatively less developed and pale. Therefore, this option is the most appropriate answer.

2. Fe Deficiency Anemia: Iron deficiency anemia is the most common type of anemia worldwide, resulting from a lack of iron in the body. Iron is a critical component of hemoglobin, which is responsible for carrying oxygen in red blood cells. In this condition, the body produces smaller than normal red blood cells (microcytic) that lack hemoglobin, leading to decreased oxygen transport. The nucleus and cytoplasm of the erythrocytes are typically smaller than normal, and there is no significant asynchrony in their development. Hence, this option is not a characteristic feature of nuclear cytoplasmic asynchrony.

3. Erythroblastosis Fetalis: This is a condition that occurs when an Rh-negative mother has an Rh-positive fetus. The mother's immune system produces antibodies against the fetal red blood cells, leading to their destruction. This causes anemia in the newborn. However, erythroblastosis fetalis is not typically associated with nuclear cytoplasmic asynchrony. The anemia is a result of hemolysis (destruction of red blood cells) rather than an intrinsic defect in the development of the cells themselves. Thus, this option is not the correct answer for this characteristic feature.

correct answer is:
1. Megaloblastic anemia

This is because megaloblastic anemia is the condition where nuclear cytoplasmic asynchrony is a hallmark feature due to the disproportionate growth of the nucleus and cytoplasm in red blood cell precursors, resulting from vitamin B12 or folic acid deficiencies affecting DNA synthesis.

Mcroscopic picture of red blood cells (RBCs) in thalassemia, the following characteristics are typically observed:

1. Microcytic: The RBCs are smaller than normal (microcytic) due to the reduced hemoglobin content.
2. Hypochromic: The RBCs have a lower concentration of hemoglobin, leading to a paler appearance (hypochromic).
3. Target cells: These are RBCs that have a bullseye appearance due to an abnormal distribution of hemoglobin within the cell. Target cells are often seen in thalassemia due to the imbalance of globin chains and the resultant membrane changes.